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You searched “Important Geophysical Phenomena”. Your tag search matches the following results:

Heat Waves and Heat Dome

Why in News The Pacific North-west, known for its moderate climate, is experiencing a “historic” heat wave. The heat wave is being...

20 Jul 2021 Important Geophysical Phenomena
Moon’s Wobble Effect

Why in News Recently, the National Aeronautics and Space Administration (NASA) has highlighted Moon’s Wobble as a potential problem in the...

19 Jul 2021 Important Geophysical Phenomena
Sir Chettur Sankaran Nair

Why in News A biopic on Sir Chettur Sankaran Nair will be produced. It will be based on the book, ‘The case that shook the empire’...

06 Jul 2021 Important Geophysical Phenomena
Discrete Auroras of Mars

Why in News Recently, the UAE’s Hope spacecraft has captured images of glowing atmospheric lights in the Mars night sky, known as discrete...

06 Jul 2021 Important Geophysical Phenomena
Heat Dome

Why in News Recently, the Pacific Northwest and some parts of Canada recorded temperatures around 47 degrees, causing a "historic" heat...

02 Jul 2021 Important Geophysical Phenomena
Changing Monsoon & Agriculture

This article is based on “Make a drop count: Southwest monsoon patterns are changing” which was published in The Times of India on...

01 Jul 2021 Important Geophysical Phenomena
Summer Solstice: 21st June

Why in News 21st June is the longest day in the Northern Hemisphere, technically this day is referred to as Summer solstice. In Delhi, the day...

21 Jun 2021 Important Geophysical Phenomena
Early Southwest Monsoon

Why in News After arriving at the Kerala Coast two days behind the schedule, the Southwest Monsoon has hit early across some areas of south...

16 Jun 2021 Important Geophysical Phenomena
Black Carbon and Glacier Melting

Why in News The report titled “Glaciers of the Himalayas: Climate Change, Black Carbon and Regional Resilience” says that the glaciers...

05 Jun 2021 Important Geophysical Phenomena
Cyclone Yaas

Why in News Recently, cyclone Yaas made landfall south of Balasore in Odisha. Earlier, another cyclonic storm named ‘Cyclone Tauktae’...

29 May 2021 Important Geophysical Phenomena
Total Lunar Eclipse and Supermoon

Why in News Two celestial events - Total Lunar Eclipse and Supermoon - together coincide on 26th May 2021. Key Points Supermoon: A supermoon...

26 May 2021 Important Geophysical Phenomena
Cyclone Tauktae

Why in News Recently, Cyclone Tauktae made landfall in Gujarat. The cyclone has left a trail of destruction as it swept through the coastal...

18 May 2021 Important Geophysical Phenomena
Climate Change Causing Shift in Earth’s Axis

Why in News A study published in Geophysical Research Letters of the American Geophysical Union (AGU) says that due to the significant melting of...

03 May 2021 Important Geophysical Phenomena
Sulphur Dioxide Emissions from Caribbean Volcano

Why in News The Sulphur Dioxide (SO2) emissions from a volcanic eruption in the Caribbean (La Soufriere Volcano) have reached India, sparking fear...

20 Apr 2021 Important Geophysical Phenomena
Effect of Dust on Monsoon

Why in News Recently, a study details how the Indian monsoon gets influenced by the atmospheric dust particles swept up by winds from deserts in the...

05 Apr 2021 Important Geophysical Phenomena
Sangay Volcano: Ecuador

Why in News Recently, Ecuador’s Sangay volcano erupted. Key Points About Sangay Volcano: Sangay volcano is one of the highest active...

13 Mar 2021 Important Geophysical Phenomena
Declining Rainfall in Cherrapunji

Why in News A recent study that looked at the rainfall pattern in the past 119 years found a decreasing trend at Cherrapunji (Meghalaya) and nearby...

22 Feb 2021 Important Geophysical Phenomena
Deglaciation and Threats

Deglaciation Glaciers, ice caps and continental ice sheets cover some 10% of the earth’s land surface at the present time, whereas during...

22 Feb 2021 Important Geophysical Phenomena
Glaciers

About A glacier is a large, perennial accumulation of crystalline ice, snow, rock, sediment, and water that originates on land and moves down...

15 Feb 2021 Important Geophysical Phenomena
Mapping Seismic Hazard of Eastern Himalaya

Why in News Recently, scientists have found the first geological evidence of an earthquake on the border of Assam and Arunachal Pradesh, documented...

09 Feb 2021 Important Geophysical Phenomena

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		'title' => 'Heat Waves and Heat Dome',
		'description' => '<h3>Why in News</h3>
<ul style="list-style-type: square;">
<li>The Pacific North-west, known for its moderate climate, is experiencing a<strong> &ldquo;historic&rdquo;</strong> heat wave. The heat wave is being described as a &ldquo;<a href="/daily-updates/daily-news-analysis/heat-dome" target="_blank" rel="noopener"><strong>Heat Dome</strong></a>&rdquo;. <br />
<ul style="list-style-type: circle;">
<li>It has stretched emergency services, with at least 134 people dying suddenly since the last few days in parts of Canada.</li>
</ul>
</li>
</ul>
<h3>Heat Waves and Heat Dome</h3>
<ul style="list-style-type: square;">
<li><strong>Heat Wave:</strong> <br />
<ul style="list-style-type: circle;">
<li>A heat wave is a period of abnormally high temperatures, more than the normal maximum temperature that lasts for more than two days.</li>
<li>Heat waves can occur with or without high humidity and have the potential to cover a large area, exposing a high number of people to <strong>hazardous heat.</strong></li>
<li><strong>Increasing Trend of Heat Waves:</strong><br />
<ul style="list-style-type: disc;">
<li>In the past few decades, heat waves have become larger, <strong>affecting 25% more land area in the <a href="/daily-updates/daily-news-analysis/autumnal-equinox-in-northern-hemisphere" target="_blank" rel="noopener">Northern Hemisphere</a></strong> than they did in 1980. </li>
<li>Including the <strong>ocean areas, heat waves have grown by 50%.</strong></li>
</ul>
</li>
</ul>
</li>
<li><strong>Heat Dome:</strong> <br />
<ul style="list-style-type: circle;">
<li>A heat dome occurs when the atmosphere traps hot ocean air like a lid or cap.</li>
<li>As per <strong>National Oceanic and Atmospheric Administration (NOAA), USA,</strong> a heat dome is created when strong high-pressure atmospheric conditions combine with weather patterns like <strong><a href="/to-the-points/paper1/el-nino-and-la-nina" target="_blank" rel="noopener">La Ni&ntilde;a</a>.</strong> </li>
<li>They are <strong>more likely to form during La Ni&ntilde;a years</strong> like 2021, when waters are cool in the eastern Pacific and warm in the western Pacific. creating vast areas of sweltering. </li>
<li><strong>Duration of Heat Domes:</strong> <br />
<ul style="list-style-type: disc;">
<li>According to NOAA, a heat dome typically lasts<strong> a week.</strong> </li>
<li>The formation after a week becomes too bog to keep standing and falls over, releasing the trapped air and ending the swelter. </li>
</ul>
</li>
</ul>
</li>
<li><strong>Causes of Formation of Heat Dome: </strong><br />
<ul style="list-style-type: circle;">
<li><strong>Change in Ocean Temperature:</strong> The phenomenon begins when there is a <strong>strong change (or gradient) in ocean temperatures.</strong> <br />
<ul style="list-style-type: disc;">
<li>In the process known as <strong>convection,</strong> the gradient causes more warm air, heated by the ocean surface, to rise over the ocean surface.</li>
<li>As prevailing winds move the hot air east, the northern shifts of the jet stream trap the air and move it toward land, where it sinks, <strong>resulting in heat waves.</strong></li>
</ul>
</li>
<li><strong>Change in Atmospheric Pressure:</strong> Heat waves begin when <strong>high pressure in the atmosphere moves in and pushes warm air</strong> toward the ground. This effect is fuelled by heat rising from the ocean, creating an amplification loop.<br />
<ul style="list-style-type: disc;">
<li>The high-pressure system pressing down on the ground expands vertically, forcing other weather systems to change course. <br />
<ul style="list-style-type: disc;">
<li>It even minimizes wind and cloud cover, making the air more stifling. </li>
<li>This is also why a heat wave parks itself over an area for several days or longer.</li>
</ul>
</li>
</ul>
</li>
<li><strong>Climate Change:</strong> The rising temperatures lead to hotter weather. Heat waves have been a regular phenomenon on land. <br />
<ul style="list-style-type: disc;">
<li>However, <strong>global warming has caused them to be hotter with a longer duration</strong> and an increased frequency.</li>
<li>Scientists studying the climate tend to agree that the heat waves occurring today are more likely to be a result of climate change for which humans are responsible.</li>
</ul>
</li>
</ul>
</li>
</ul>
<p><a href="http://www.drishtiias.com/images/uploads/1626762592_image1.jpg" target="_blank" rel="noopener"><img class="content-img" src="http://www.drishtiias.com/images/uploads/1626762592_image1.jpg" style="display: block; margin-left: auto; margin-right: auto;" width="700" caption="false" /></a></p>
<ul style="list-style-type: square;">
<li><strong>Impact of Heat Waves and Heat Domes:</strong><br />
<ul style="list-style-type: circle;">
<li><strong>Risk of Wildfires:</strong> The heat domes act as fuel to <strong><a href="/daily-updates/daily-news-analysis/forest-fires-a-very-big-concern" target="_blank" rel="noopener">wildfires</a></strong>, which destroys a lot of land area every year in countries like the US.</li>
<li><strong>Prevents Cloud Formation:</strong> The condition also <strong>prevents clouds from forming,</strong> allowing for more radiation from the sun to hit the ground. </li>
<li><strong>Heat Strokes and Sudden Fatalities:</strong> The very high temperatures or humid conditions pose an elevated risk of <a href="/daily-updates/daily-news-analysis/heat-waves" target="_blank" rel="noopener"><strong>heatstroke</strong></a> or<strong> heat exhaustion.</strong><br />
<ul style="list-style-type: disc;">
<li><strong>Older people and people with chronic illness</strong> such as <a href="/daily-updates/daily-news-analysis/higher-mortality-from-cardio-vascular-diseases" target="_blank" rel="noopener"><strong>heart disease</strong></a>, <a href="/daily-updates/daily-news-analysis/acute-respiratory-infections" target="_blank" rel="noopener"><strong>respiratory disease</strong></a>, and <a href="/daily-updates/daily-news-analysis/world-diabetes-day-2019#:~:text=The%20World%20Health%20Organisation%20(WHO,is%20%E2%80%9CFamily%20and%20Diabetes%E2%80%9D." target="_blank" rel="noopener"><strong>diabetes</strong></a> are <strong>more susceptible to heatstroke,</strong> as the body&rsquo;s ability to regulate heat deteriorates with age.</li>
<li>Houses without air conditioners experience an unbearable rise in temperature of their home which can lead to<strong> sudden deaths.</strong></li>
</ul>
</li>
<li><strong>Effect on Vegetation:</strong> The trapping of heat can also <strong>damage crops, dry out vegetation</strong> and result in <a href="/daily-updates/daily-news-analysis/el-ni%C3%B1o-drought" target="_blank" rel="noopener"><strong>droughts.</strong></a></li>
<li><strong>Increased Energy Demands:</strong> The sweltering heat wave also leads to rise in energy demand, especially electricity, leading to pushing up rates.</li>
<li><strong>Power Related Issues:</strong> Heat waves are often high mortality disasters.<br />
<ul style="list-style-type: disc;">
<li>Avoiding heat-related disasters depends on the resilience of the electrical grid, which can fail if electricity demand due to air conditioning use exceeds supply.</li>
<li>As a result, there is the <strong>double risk of infrastructure failure and health impacts.</strong></li>
</ul>
</li>
</ul>
</li>
</ul>
<h3>Steps for Avoiding Heat Waves</h3>
<ul style="list-style-type: square;">
<li><strong>Individual Level: </strong><br />
<ul style="list-style-type: circle;">
<li><strong>Staying Hydrated:</strong> Staying indoor and at rest in a very dry room with about 10% relative humidity, and drinking water constantly (for producing sweat), can help avoid overheating at temperatures as high as 46℃.<br />
<ul style="list-style-type: disc;">
<li>However, there is a limit to this, called the<strong> wet-bulb temperature,</strong> which considers heat and humidity, beyond which humans cannot tolerate high temperatures.</li>
</ul>
</li>
<li><strong>Altering Workout Routines:</strong> Exercising early in the morning when it is still cool or in air conditioned indoor spaces. <br />
<ul style="list-style-type: disc;">
<li>Skipping workout routines can also be considered given the extreme heat. </li>
</ul>
</li>
</ul>
</li>
<li><strong>Public Level: </strong><br />
<ul style="list-style-type: circle;">
<li><strong>Public Cooling Shelters:</strong> A number of emergency cooling shelters can be opened so that people without domestic air conditioning units can escape the heat.<br />
<ul style="list-style-type: disc;">
<li>Air-conditioned rooms and buildings are the biggest help to people caught under a heat dome.</li>
</ul>
</li>
<li><strong>Portable ACs:</strong> Portable air-conditioning units, along with fans and even ice are also useful. </li>
</ul>
</li>
<li><strong>Long Term Solutions: </strong><br />
<ul style="list-style-type: circle;">
<li><strong>Afforestation:</strong> Trees don&rsquo;t just provide much-needed shade for a sweaty city. The water evaporating from their leaves can cool a neighborhood by a few degrees during the hottest periods.<br />
<ul style="list-style-type: disc;">
<li>Tree leaves also absorb and filter local air pollution; heat waves can worsen urban smog, which may put comorbids at risk.</li>
</ul>
</li>
<li><strong>Replacing Dark Roofs:</strong> A big reason that cities are so much hotter than rural areas is that they are covered by dark roofs, roads and parking lots that absorb and retain heat. <br />
<ul style="list-style-type: disc;">
<li>Replacing the dark surfaces with lighter more reflective materials will result in a comparatively cooler environment.</li>
</ul>
</li>
<li><strong>Preparing for the Blackout:</strong> A widespread blackout during a heat wave can leave millions of people without electricity for fans or air-conditioners. <br />
<ul style="list-style-type: disc;">
<li>Smarter grids and new forecasting tools could help electric utilities prepare for heat waves. </li>
<li>Using electronic controls to pre-cool buildings before temperatures peak in the daytime.</li>
</ul>
</li>
</ul>
</li>
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		'article_id' => (int) 8909,
		'category_id' => (int) 21,
		'title' => 'Moon’s Wobble Effect',
		'description' => '<h3>Why in News</h3>
<p>Recently, the <a href="/important-institutions/drishti-specials-important-institutions-international-institution/national-aeronautics-and-space-administration-nasa" target="_blank" rel="noopener"><strong>National Aeronautics and Space Administration</strong></a> (NASA) has highlighted<strong> Moon&rsquo;s Wobble</strong> as a<strong> potential problem in the near future.</strong></p>
<h3>Key Points</h3>
<ul style="list-style-type: square;">
<li><strong>Moon&rsquo;s Wobble:</strong><br />
<ul style="list-style-type: circle;">
<li>When the Moon makes its <strong>elliptical orbit,</strong> its<strong> velocity varies and alters causing our perspective of the "light side"</strong> to appear at <strong>slightly different angles.</strong> This is what it calls the Moon&rsquo;s wobble or that is how it appears to our eyes.</li>
<li>It is a <strong>cyclical shift in the moon&rsquo;s orbit,</strong> it is a <strong>regular swaying (Oscillation) in the moon&rsquo;s orbit.</strong></li>
<li>It was first documented <strong>way back in 1728.</strong> This wobble takes<strong> over an 18.6-year</strong> period to complete. It acts as a background of <a href="/daily-updates/daily-news-analysis/rising-sea-levels" target="_blank" rel="noopener"><strong>sea level rise.</strong></a></li>
</ul>
</li>
<li><strong>Impact of Wobble on Earth:</strong><br />
<ul style="list-style-type: circle;">
<li>The moon wobble impacts the gravitational pull of the moon, and therefore, indirectly influences <strong>the ebb and flow of tides</strong> on the Earth.</li>
<li>Each wobble cycle has the <strong>power to amplify and suppress the tides on Earth.</strong><br />
<ul style="list-style-type: disc;">
<li>During<strong> half of the Moon&rsquo;s orbit of 18.6 years, the Earth's regular tides are suppressed</strong> i.e. high tides are lower than normal and low tides higher than normal (Current situation).</li>
<li>In the <strong>other half, the effect is reversed, which is called the tide-amplifying phase</strong> of the Moon.</li>
</ul>
</li>
</ul>
</li>
<li><strong>Related Concerns:</strong><br />
<ul style="list-style-type: circle;">
<li>The<strong> lunar cycle is expected to shift again by mid-2030,</strong> and in the coming phase, the <strong>tides will amplify once again.</strong></li>
<li>The upcoming changes in the lunar cycle will pose a serious threat, as the amplified <strong>high tides coupled with the rising sea levels</strong> will make the risk of flooding far greater across<strong> all coastal regions of the globe.</strong><br />
<ul style="list-style-type: disc;">
<li>It raises<strong> the baseline,</strong> and the more the baseline is raised, the smaller the weather event to cause flooding.</li>
</ul>
</li>
<li>The <strong>high tide-associated <a href="/daily-updates/daily-news-editorials/flood-management-in-india" target="_blank" rel="noopener">floods</a></strong>&mdash;also known as nuisance floods or sunny day floods&mdash;<strong>may occur in clusters that could last for months</strong> or even for longer periods.</li>
<li>This surge will be closely associated with the <strong>position of the Moon, Earth and the Sun. </strong></li>
</ul>
</li>
</ul>
<div class="border-bg">
<p><strong>Tides</strong></p>
<ul style="list-style-type: square;">
<li><strong>About:<a href="http://www.drishtiias.com/images/uploads/1626691979_image3.png" target="_blank" rel="noopener"><img class="content-img" src="http://www.drishtiias.com/images/uploads/1626691979_image3.png" style="float: right;" width="350" caption="false" /></a></strong><br />
<ul style="list-style-type: circle;">
<li>Tides can be defined as the <strong>alternate rise and fall of the ocean water. </strong></li>
</ul>
</li>
<li><strong>Occurrence:</strong><br />
<ul style="list-style-type: circle;">
<li>It is caused by the combined effects of the <strong>gravitational force</strong> exerted on Earth<strong> by the Sun,</strong> the gravitational force exerted on Earth <strong>by the Moon and rotation of the Earth.</strong></li>
</ul>
</li>
<li><strong>Types:</strong> <br />
<ul style="list-style-type: circle;">
<li><strong>Spring Tide:</strong> It occurs during the<strong> full moon and new moon days</strong> when the sun, the moon and the earth are in the same line twice each lunar month all year long, without regard to the season.</li>
<li><strong>Neap Tide:</strong> It occurs when the moon is in<strong> its first and last quarter,</strong> the ocean waters get drawn<strong> in diagonally opposite directions</strong> by the gravitational pull of sun and earth resulting in low tides.</li>
</ul>
</li>
<li><strong>Stages of Tidal Changes:<a href="http://www.drishtiias.com/images/uploads/1626691998_image5.png" target="_blank" rel="noopener"><img class="content-img" src="http://www.drishtiias.com/images/uploads/1626691998_image5.png" style="float: right;" width="350" caption="false" /></a></strong><br />
<ul style="list-style-type: circle;">
<li><strong>High tide</strong> is the stage when the tidal crest arrives at a particular location on shore, raising the local sea level.</li>
<li><strong>Low tide</strong> is the stage when the trough arrives, lowering the local sea level.</li>
<li><strong>Flood tide</strong> is a rising or incoming tide between low tide and high tide.</li>
<li><strong>Ebb tide</strong> is a falling or outgoing tide between high tide and low tide. <br />
<ul style="list-style-type: disc;">
<li>The vertical distance between high tide and low tide is the tidal range.</li>
</ul>
</li>
</ul>
</li>
<li><strong>Impact:</strong><br />
<ul style="list-style-type: circle;">
<li>Tides affect other aspects of <strong>oceanic life, including the reproductive activities</strong> of fish and ocean plants.</li>
<li>High tides <strong>help in navigation.</strong> They raise the water level close to the shores which helps the <strong>ships to arrive at the harbour more easily.</strong></li>
<li>Tides stirr the ocean water that<strong> makes habitable climatic conditions</strong> and balance the temperatures on the planets.</li>
<li>The fast movement of water<strong> during the inflow and outflow</strong> will provide a source of renewable energy to communities living along the coast.</li>
</ul>
</li>
</ul>
</div>
<p><a href="https://indianexpress.com/article/explained/explained-how-the-moon-wobble-affects-rising-tides-7410814/" target="_blank" rel="noopener"><strong>Source: IE</strong></a></p>',
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		'article_id' => (int) 8793,
		'category_id' => (int) 21,
		'title' => 'Sir Chettur Sankaran Nair',
		'description' => '<h3>Why in News</h3>
<p>A biopic on<strong> Sir Chettur Sankaran Nair</strong> will be produced.</p>
<ul style="list-style-type: square;">
<li>It will be <strong>based on the book, &lsquo;The case that shook the empire&rsquo;</strong> written by Raghu Palat and Pushpa Palat in 2019.</li>
</ul>
<p><a href="http://www.drishtiias.com/images/uploads/1625565045_image8.jpg" target="_blank" rel="noopener"><img class="content-img" src="http://www.drishtiias.com/images/uploads/1625565045_image8.jpg" style="display: block; margin-left: auto; margin-right: auto;" width="300" caption="false" /></a></p>
<h3>Key Points</h3>
<ul style="list-style-type: square;">
<li><strong>Brief Profile:</strong>
<ul style="list-style-type: circle;">
<li><strong>Born in the year 1857</strong> in <strong>Mankara village</strong> of<strong> Malabar&rsquo;s Palakkad district.</strong></li>
<li>Known for being<strong> a passionate advocate for social reforms</strong> and<strong> a firm believer in the self-determination of India.</strong></li>
<li>He was <strong>an acclaimed lawyer and judge</strong> in the Madras High Court.</li>
</ul>
</li>
<li><strong>Achievements:</strong>
<ul style="list-style-type: circle;">
<li><strong>President of INC:</strong> He was one of the early builders of the <a href="/to-the-points/paper1/important-indian-national-congress-sessions" target="_blank" rel="noopener"><strong>Indian National Congress (INC)</strong></a>, formed in 1885.
<ul style="list-style-type: disc;">
<li>In 1897, he became the <strong>youngest president of the INC</strong> in the history of the party till then, and the <strong>only Malayali to hold the post ever.</strong></li>
</ul>
</li>
<li><strong>Member of the Raleigh University Commission:</strong> In 1902, <a href="/to-the-points/paper1/reforms-and-administration-under-lord-curzon" target="_blank" rel="noopener"><strong>Lord Curzon</strong></a> appointed him a member of the <strong>Raleigh University Commission.</strong></li>
<li><strong>Knighthood:</strong> In 1904, he was appointed as Companion of the Indian Empire by the King-Emperor and in 1912 he was knighted.</li>
<li><strong>Judge in Madras High Court:</strong> He was appointed as a permanent judge in the Madras High Court<strong> in 1908.</strong></li>
<li><strong>Part of Viceroy Council:</strong> In 1915, he became part of the Viceroy&rsquo;s Council, put in charge of the education portfolio.</li>
</ul>
</li>
<li><strong>Role in Freedom Movement:</strong>
<ul style="list-style-type: circle;">
<li>As a fervent freedom fighter, he firmly believed in India&rsquo;s<strong> right for self-government.</strong></li>
<li><strong>Montagu-Chelmsford Reforms:</strong> In 1919,<strong> as part of the Viceroy&rsquo;s Executive Council,</strong> he played an important role in the expansion of provisions in the <a href="/to-the-points/paper1/government-of-india-act-1919#:~:text=Montagu%2DChelmsford%20Reforms%20which%20came,as%20Provincial%20levels%20of%20Government." target="_blank" rel="noopener"><strong>Montagu-Chelmsford reforms.</strong></a>
<ul style="list-style-type: disc;">
<li>It<strong> introduced a system of dyarchy</strong> in the provinces and<strong> increased participation of Indians in the administration.</strong></li>
</ul>
</li>
<li><strong>Resignation from the Viceroy&rsquo;s Council:</strong> When the massacre of <a href="/daily-updates/daily-news-analysis/jallianwala-bagh-massacre-2" target="_blank" rel="noopener"><strong>Jallianwala Bagh</strong></a> (13<sup>th</sup> April, 1919) happened, he resigned from the Viceroy&rsquo;s Council in protest.
<ul style="list-style-type: disc;">
<li>His resignation shook the British government. In the immediate aftermath, <strong>press censorship in Punjab was lifted </strong>and<strong> martial law terminated.</strong></li>
<li>Further, a committee was set up under<a href="/current-affairs-news-analysis-editorials/news-analysis/08-04-2019" target="_blank" rel="noopener"><strong> Lord William Hunter</strong></a> to examine the disturbances in Punjab.</li>
</ul>
</li>
<li><strong>Critical of Gandhian Methods:</strong> In his book <strong>&lsquo;Gandhi and Anarchy&rsquo;,</strong> he spelt out his critique of <a href="/to-the-points/paper4/gandhian-ideologies" target="_blank" rel="noopener"><strong>Gandhi&rsquo;s methods</strong></a>, especially those of <strong>non-violence, civil disobedience </strong>and<strong> non-cooperation.</strong>
<ul style="list-style-type: disc;">
<li>He believed that any of these movements was destined to lead to riots and bloodshed.</li>
</ul>
</li>
</ul>
</li>
<li><strong>Legal Battle against Michael O&rsquo;Dwyer:</strong>
<ul style="list-style-type: circle;">
<li><strong>Defamation Trial:</strong> Sir Chettur Sankaran Nair accused<strong> Lieutenant-Governor of Punjab, <a href="/daily-updates/daily-news-editorials/jallianwala-bagh-massacre" target="_blank" rel="noopener">Michael O&rsquo;Dwyer</a></strong> in his book, <strong>&lsquo;Gandhi and anarchy&rsquo;</strong> for being responsible for the atrocities at the <a href="/daily-updates/daily-news-analysis/jallianwala-bagh-massacre-3" target="_blank" rel="noopener"><strong>Jallianwala Bagh massacre.</strong></a>
<ul style="list-style-type: disc;">
<li>For this he faced a defamation trial filed by <a href="/daily-updates/daily-news-editorials/jallianwala-bagh-massacre" target="_blank" rel="noopener"><strong>Michael O&rsquo;Dwyer</strong></a> in England.</li>
</ul>
</li>
<li><strong>Impact of Trial:</strong> Though Nair lost the case, the trial had a resounding impact on the British empire in India.
<ul style="list-style-type: disc;">
<li>At a time when the nationalist movement was gaining momentum, Indians saw in the judgement a clear bias of the British government and an effort to shield those who committed atrocities against their own people.</li>
<li>The verdict was momentous in that it<strong> strengthened the determination of the nationalists to fight for self-government.</strong></li>
</ul>
</li>
</ul>
</li>
<li><strong>Social Reforms:</strong>
<ul style="list-style-type: circle;">
<li>As a Madras High Court judge, his best-known judgments clearly indicate his commitment to social reforms.</li>
<li>In<em><strong> Budasna v Fatima (1914),</strong></em> he passed a radical judgement when he ruled that those who converted to Hinduism cannot be treated as outcastes.</li>
<li>In a few other cases, he upheld inter-caste and inter-religious marriages.</li>
</ul>
</li>
</ul>
<p><a href="https://indianexpress.com/article/explained/chettur-sankaran-nair-lawyer-british-movie-7390007/" target="_blank" rel="noopener"><strong>Source: IE</strong></a></p>',
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	(int) 3 => object(Cake\ORM\Entity) {

		'article_id' => (int) 8789,
		'category_id' => (int) 21,
		'title' => 'Discrete Auroras of Mars',
		'description' => '<h3>Why in News</h3>
<p>Recently, the <strong>UAE&rsquo;s <a href="/daily-updates/daily-news-analysis/uae-s-hope-mars-mission" target="_blank" rel="noopener">Hope spacecraft</a></strong> has captured <strong>images of glowing atmospheric lights in the Mars night sky, known as discrete auroras.</strong></p>
<ul style="list-style-type: square;">
<li>The Hope Probe, the Arab world&rsquo;s first mission to Mars, took off from Earth in July 2020, and has been orbiting the Red Planet (Mars) since February 2021. It is expected to create the <strong>first complete portrait of the planet&rsquo;s atmosphere.</strong></li>
</ul>
<p><a href="http://www.drishtiias.com/images/uploads/1625558022_image.png" target="_blank" rel="noopener"><strong><img class="content-img" src="http://www.drishtiias.com/images/uploads/1625558022_image.png" style="display: block; margin-left: auto; margin-right: auto;" width="400" caption="false" /></strong></a></p>
<h3>Key Points</h3>
<ul style="list-style-type: square;">
<li><strong>Auroras:</strong><br />
<ul style="list-style-type: circle;">
<li>An Aurora is <strong>a display of light in the sky predominantly seen in the high latitude regions</strong> (Arctic and Antarctic). It is <strong>also known as a Polar light.</strong></li>
<li>They commonly occur at high northern and southern latitudes, less frequent at mid-latitudes, and seldom seen near the equator.</li>
<li>While <strong>usually a milky greenish color</strong>, auroras can also show red, blue, violet, pink, and white. These colors appear in a variety of continuously changing shapes.</li>
<li>Auroras are <strong>not just something that happens on Earth.</strong> If a planet has an atmosphere and magnetic field, they probably have auroras.</li>
</ul>
</li>
<li><strong>Cause of Auroras on Earth:</strong><br />
<ul style="list-style-type: circle;">
<li>Auroras are caused <strong>when charged particles ejected from the Sun&rsquo;s surface - called the solar wind - enter the Earth&rsquo;s atmosphere.</strong></li>
<li>The typical aurora is <strong>caused by collisions between charged particles from space with the oxygen and nitrogen in Earth&rsquo;s upper atmosphere.</strong></li>
<li>The electrons - which come from the<a href="/daily-updates/daily-news-analysis/1-d-simulation-code-to-study-earth-s-magnetosphere" target="_blank" rel="noopener"><strong> Earth&rsquo;s magnetosphere</strong></a>, the region of space controlled by Earth&rsquo;s magnetic field - transfer their energy to the oxygen and nitrogen atoms and molecules, making them &ldquo;excited&rdquo;.</li>
<li>When a large number of electrons come from the magnetosphere to bombard the atmosphere, the<strong> oxygen and nitrogen can emit enough light for the eye to detect, giving us beautiful auroral displays.</strong></li>
<li>In the <strong>northern part of our globe, </strong>the<strong> polar lights are called aurora borealis or Northern Lights</strong>, and are seen from the US (Alaska), Canada, Iceland, Greenland, Norway, Sweden and Finland.</li>
<li>In the <strong>south, they are called aurora australis or southern lights</strong>, and are visible from high latitudes in Antarctica, Chile, Argentina, New Zealand and Australia.</li>
</ul>
</li>
<li><strong>Discrete Auroras of Mars:</strong><br />
<ul style="list-style-type: circle;">
<li>Unlike auroras on Earth, which are seen only near the north and south poles, <strong>Discrete Auroras (DA) on Mars are seen all around</strong> the planet at night time.</li>
<li>These DAs are traced out where <strong>energetic particles excite the atmosphere</strong> after being funneled down by a patchy network of crustal <strong>magnetic fields that originate from minerals</strong> on the surface of Mars.</li>
</ul>
</li>
<li><strong>Martian Auroras are Different:</strong><br />
<ul style="list-style-type: circle;">
<li>Unlike Earth, which has a strong magnetic field, the <strong>Martian magnetic field has largely died out.</strong> This is because the molten iron at the interior of the planet - which produces magnetism - has cooled.</li>
<li>However, the <strong>Martian crust</strong>, which hardened billions of years ago when the magnetic field still existed, <strong>retains some magnetism.</strong></li>
<li>So, in contrast with Earth, which acts like one single bar magnet, <strong>magnetism on Mars is unevenly distributed</strong>, with fields strewn across the planet and differing in direction and strength.</li>
<li>These <strong>disjointed fields channel the solar wind to different parts of the Martian atmosphere</strong>, creating &ldquo;discrete&rdquo; auroras over the entire surface of the planet as charged particles interact with atoms and molecules in the sky&ndash; as they do on Earth.</li>
</ul>
</li>
<li><strong>Significance:</strong><br />
<ul style="list-style-type: circle;">
<li>Studying Martian auroras is important for scientists, for it <strong>can offer clues as to why the Red Planet lost its magnetic field and thick atmosphere</strong>&ndash; among the essential requirements for sustaining life.</li>
<li>With the information gathered during the UAE&rsquo;s Mars mission, scientists will have<strong> a better understanding of the climate dynamics of different layers of Mars&rsquo; atmosphere.</strong></li>
</ul>
</li>
</ul>
<div class="border-bg">
<p><strong>Other Mars Missions</strong></p>
<ul style="list-style-type: square;">
<li><a href="/daily-updates/daily-news-analysis/nasa-s-mars-2020-mission" target="_blank" rel="noopener"><strong>NASA's Mars 2020 Mission</strong></a> <strong>(Perseverance Rover)</strong>: The mission is designed to better understand the geology of Mars and seek signs of ancient life.</li>
<li><strong><a href="/daily-updates/daily-news-analysis/tianwen-1-china-s-mars-mission-1" target="_blank" rel="noopener">Tianwen-1: China's Mars Mission</a>:</strong> It was launched in 2019 to conduct scientific investigations into the planet&rsquo;s soil, geological structure, environment, atmosphere and water.</li>
<li><strong>India&rsquo;s <a href="/important-institutions/drishti-specials-important-institutions-national-institutions/indian-space-research-organisation-isro" target="_blank" rel="noopener">Mars Orbiter Mission (MOM)</a> or Mangalyaan:</strong> It was launched from the Satish Dhawan Space Centre in Andhra Pradesh by Indian Space Research Organisation in November 2013.</li>
</ul>
</div>
<p><a href="https://indianexpress.com/article/explained/uae-hope-orbiter-discrete-auroras-mars-7390298/" target="_blank" rel="noopener"><strong>Source: IE</strong></a></p>',
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	(int) 4 => object(Cake\ORM\Entity) {

		'article_id' => (int) 8761,
		'category_id' => (int) 21,
		'title' => 'Heat Dome',
		'description' => '<h3>Why in News</h3>
<p>Recently, the Pacific Northwest and some parts of Canada recorded temperatures around 47 degrees, causing a "historic" heat wave.</p>
<ul style="list-style-type: square;">
<li>This is a result of a phenomenon referred to as a <strong>"heat dome".</strong></li>
</ul>
<h3>Key Points</h3>
<ul style="list-style-type: square;">
<li><strong>About:</strong><br />
<ul style="list-style-type: circle;">
<li>The phenomenon begins when there is<strong> a strong change (or gradient) in ocean temperatures.</strong> In the process<strong> known as convection,</strong> the gradient causes more warm air, heated by the ocean surface, to rise over the ocean surface.</li>
<li>As prevailing <strong>winds move the hot air east,</strong> the <strong>northern shifts of the jet stream trap the air</strong> and move it toward land, where it sinks, resulting in heat waves.<br />
<ul style="list-style-type: disc;">
<li><strong>Jet streams are relatively narrow bands of strong wind</strong> in the upper levels of the atmosphere. The winds blow <strong>from west to east in jet streams</strong> but the flow often<strong> shifts to the north and south.</strong></li>
</ul>
</li>
<li>This <strong>strong change in ocean temperature from the west to the east</strong> is the reason for the<strong> heat dome (HD).</strong><br />
<ul style="list-style-type: disc;">
<li>The<strong> western Pacific ocean&rsquo;s temperatures</strong> have increased in the past few decades and are<strong> relatively more than the temperature in the eastern Pacific.</strong></li>
</ul>
</li>
<li>HD also prevents clouds from forming, allowing for more radiation from the sun to hit the ground.</li>
<li>A heat dome is<strong> effectively what it sounds like</strong> - an area of high pressure that parks over a region like a lid on a pot, trapping heat. They are more likely to form during<a href="/to-the-points/paper1/el-nino-and-la-nina" target="_blank" rel="noopener"><strong> La Ni&ntilde;a</strong></a> years like 2021, when waters are cool in the eastern Pacific and warm in the western Pacific.</li>
</ul>
</li>
</ul>
<p><a href="http://www.drishtiias.com/images/uploads/1625217033_image1.jpg" target="_blank" rel="noopener"><img class="content-img" src="http://www.drishtiias.com/images/uploads/1625217033_image1.jpg" style="display: block; margin-left: auto; margin-right: auto;" caption="false" width="628" height="454" /></a></p>
<ul style="list-style-type: square;">
<li><strong>Heat Wave:</strong><br />
<ul style="list-style-type: circle;">
<li>A heat wave is <strong>a period of abnormally high temperatures,</strong> more than the normal maximum temperature that lasts for more than two days.</li>
<li>Heat waves <strong>typically occur between March and June,</strong> and in some rare cases even extend till July.</li>
<li>Heat waves can occur with or without high humidity and have the potential to cover a large area,<strong> &ldquo;exposing a high number of people to hazardous heat.&rdquo;</strong></li>
</ul>
</li>
<li><strong>Impact on Humans (Wet-bulb temperature):</strong><br />
<ul style="list-style-type: circle;">
<li>As long as the body is producing sweat, which is then able to evaporate quickly, the <strong>body will be able to remain cool even under high temperatures.</strong></li>
<li>Wet-bulb temperature (WBT) is <strong>a limit that considers heat and humidity beyond which humans can not tolerate high temperatures.</strong></li>
<li>Temperatures beyond WBT<strong> can cause heat related illnesses including heat stroke, heat exhaustion, sunburn and heat rashes.</strong> Sometimes these can prove fatal.</li>
</ul>
</li>
<li><strong>Effects of Heat Dome:</strong><br />
<ul style="list-style-type: circle;">
<li>Those living without an air conditioner see the temperatures of their homes rising to unbearably high, leading to sudden fatalities.</li>
<li>The trapping of heat <strong>can also damage crops, dry out vegetation and result in droughts.</strong></li>
<li>The sweltering heat wave will also<strong> lead to rise in energy demand,</strong> especially electricity, leading to pushing up rates.</li>
<li>The heat domes <strong>can also act as fuel to wildfires,</strong> which destroys a lot of land area in the US every year.</li>
</ul>
</li>
<li><strong>Climate change and heat domes:</strong><br />
<ul style="list-style-type: circle;">
<li>The weather scientists have been highlighting the effects of climate change on more extreme heat waves.<br />
<ul style="list-style-type: disc;">
<li>According to a 2017 NOAA (National Oceanic and Atmospheric Administration) survey, average US temperatures have increased since the late 19<sup>th</sup> century.</li>
</ul>
</li>
<li>However, Scientists are usually wary of linking climate change to any contemporary event mainly because of the difficulty in completely ruling out the possibility of the event having been caused by some other reason, or being a result of natural variability.</li>
</ul>
</li>
</ul>
<p><a href="https://indianexpress.com/article/explained/what-is-the-heat-dome-causing-record-high-temperatures-in-parts-of-north-america-7384994/" target="_blank" rel="noopener"><strong>Source: IE</strong></a></p>',
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	(int) 5 => object(Cake\ORM\Entity) {

		'article_id' => (int) 8754,
		'category_id' => (int) 22,
		'title' => 'Changing Monsoon & Agriculture',
		'description' => '<div class="border">
<p>This article is based on <a href="https://timesofindia.indiatimes.com/blogs/toi-editorials/make-a-drop-count-southwest-monsoon-patterns-are-changing-implications-for-farming-are-huge-and-worrisome/" target="_blank" rel="noopener"><strong>&ldquo;Make a drop count: Southwest monsoon patterns are changing&rdquo;</strong> </a>which was published in The Times of India on 29/06/2021. It talks about the effect of changing southwest monsoon patterns on Indian agriculture.</p>
</div>
<p><a href="/loksabha-rajyasabha-discussions/in-depth-monsoon-respite-for-agriculture" target="_blank" rel="noopener"><strong>Southwest monsoon</strong></a> is perhaps the most important feature of India&rsquo;s climate, because it is very critical for Indian agriculture. Therefore, long-term trends in the southwest monsoon overlap with economic security.</p>
<p>A recent study by IMD on monsoon variability over a 30-year period (1989-2018) is a wakeup call. UP, Bihar and West Bengal are three of five states that have shown a significant decreasing trend in the southwest monsoon. These states have a large bearing on India&rsquo;s agriculture output.</p>
<p>With around 55% of India&rsquo;s arable land dependent on precipitation, the amount of rainfall during the current monsoon season could sway economic activity in the agriculture sector and industries linked to it.</p>
<p>The shift in monsoon may entail grave consequences for India&rsquo;s economy, food systems and people&rsquo;s well-being.Therefore, remedial measures must be taken before it is too late.</p>
<h3>Monsoon &amp; Agriculture Linkage</h3>
<ul style="list-style-type: square;">
<li>The Southwest monsoon plays a crucial role in India&rsquo;s agriculture and affects the livelihood of a fifth of the world&rsquo;s population.</li>
<li>About 80 per cent of the annual precipitation over India occurs during the summer period, supplying water to crops during the prime agricultural season. <br />
<ul style="list-style-type: circle;">
<li>Monsoon friendly crops with a high requirement of water like sugarcane, jute and paddy can easily be cultivated during southwest monsoon.</li>
</ul>
</li>
<li>The agriculture sector in India is both economically and politically important. The industry accounts for around 14% of the country&rsquo;s $2.7 trillion economy and 42% of total employment.</li>
<li>Further, about one-third of India&rsquo;s manufacturing output &mdash; which makes up around 18% of the country&rsquo;s gross domestic product &mdash; is linked to turning agricultural products into food.</li>
<li>Therefore, too much rainfall or too little or a volatile monsoon pattern, can damage crops.</li>
</ul>
<h3>Impact of Changing Monsoon</h3>
<ul style="list-style-type: square;">
<li><strong>Depletion of Water Table:</strong> In India, a little over 50% of India&rsquo;s net sown area is under rainfed farming and a large part of the irrigated area depends on groundwater extraction through borewells, which needs to be recharged with the groundwater.<br />
<ul style="list-style-type: circle;">
<li>In the event of a poor monsoon, these aquifers may not get adequately recharged, leading to water crisis.</li>
<li>Further, according to a NITI Aayog&rsquo;s report , nearly 21 Indian cities &mdash; including New Delhi, Hyderabad and Chennai &mdash; could run out of groundwater by 2020.</li>
</ul>
</li>
<li><strong>Fiscal Burden:</strong> Multiple crop failures may require the government to actively support farmers. Most likely, it may prompt the government to raise minimum support prices for all of the current season&rsquo;s crops to help support farmers&rsquo; incomes.<br />
<ul style="list-style-type: circle;">
<li>This will have a diminishing effect on investments into agricultural investments.</li>
</ul>
</li>
<li><strong>Impacting Electricity Generation:</strong> Monsoon rains can be harnessed as hydropower, a valuable energy resource. Hydropower currently provides 25% of India&rsquo;s electricity. <br />
<ul style="list-style-type: circle;">
<li>Reservoirs are filled during the southwest monsoon rains and then the water is gradually released through dams, turning turbines to create electricity year-round.</li>
<li>During years when there is little monsoon rainfall, the reservoirs are not replenished, limiting the amount of hydroelectric power produced during the year.</li>
</ul>
</li>
<li><strong>Impacting Inflation:</strong> Normal monsoon rains keep a check on food inflation due to availability of food produce. However in a situation of drought, prices soar significantly.<br />
<ul style="list-style-type: circle;">
<li>Also, if a poor monsoon results in less crop output, the country may need to import.</li>
<li>It also impacts as many as a dozen sectors which depend on monsoon either directly or indirectly.</li>
</ul>
</li>
</ul>
<h3>Way Forward</h3>
<ul style="list-style-type: square;">
<li><strong>Addressing Water Scarcity:</strong> Water availability is a national challenge. We have 18% of the world&rsquo;s population with just 4% of freshwater resources. <br />
<ul style="list-style-type: circle;">
<li>Thus, the Indian government needs to put a high priority on investing heavily in improved water storage systems for the agricultural sector.</li>
<li>It would be worthwhile to give high priority to "more crops per drop" approach, rainwater harvesting, aquifer recharge, revival of water bodies and conservation technologies.</li>
</ul>
</li>
<li><strong>Addressing Inefficient Water Use:</strong> Water use patterns are awfully inefficient in India, where Indian farmers use two to four times more water to produce a unit of any major food crop.<br />
<ul style="list-style-type: circle;">
<li>Thus, Indian agriculture needs to adopt newer, less water-intensive technologies faster.</li>
<li>In this case, it needs a doubling down on efforts such as the ongoing government of India schemes to incentivise the use of micro irrigation measures that use water more efficiently.</li>
</ul>
</li>
</ul>
<h3>Conclusion</h3>
<p>Global climate change is not a new phenomenon. The effect of climate change poses many threats; one of the important consequences is bringing about changes in southwest monsoon and its impact on agriculture.</p>
<p>As India has set a target of halving greenhouse gas emissions by 2050 [15]. There is an urgent need for coordinated efforts to strengthen the research to assess the impact of climate change on agriculture, forests, animal husbandry, aquatic life and other living beings.</p>
<table border="1" style="border-collapse: collapse; width: 100%;">
<tbody>
<tr>
<td style="width: 100%; border-style: dotted; border-color: #ff0000; background-color: #fffef7;">
<p><span style="color: #000080;"><em><strong>Drishti Mains Question</strong></em></span></p>
<p>The shift in monsoon may entail grave consequences for India&rsquo;s economy, food systems and people&rsquo;s well-being.Discuss.</p>
</td>
</tr>
</tbody>
</table>',
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		'article_id' => (int) 8658,
		'category_id' => (int) 21,
		'title' => 'Summer Solstice: 21st June',
		'description' => '<h3>Why in News</h3>
<p>21<sup>st</sup> June is the <strong>longest day</strong> in the Northern Hemisphere, technically this day is referred to as <strong>Summer solstice.</strong> In <strong>Delhi, the day length</strong> is around <strong>14 hours.</strong></p>
<ul style="list-style-type: square;">
<li>The amount of light received by <strong>a specific area</strong> in the <strong>Northern Hemisphere</strong> during the summer solstice depends on the<strong> latitudinal location</strong> of the place.</li>
<li>21<sup>st</sup> June is also observed as the <a href="/daily-updates/daily-news-analysis/international-day-of-yoga" target="_blank" rel="noopener"><strong>International Yoga Day.</strong></a></li>
</ul>
<h3>Key Points</h3>
<ul style="list-style-type: square;">
<li><strong>Meaning of the Word &lsquo;Solstice&rsquo;:</strong><br />
<ul style="list-style-type: circle;">
<li>It is a Latin word that means <strong>&lsquo;stalled sun&rsquo;.</strong> It is a natural phenomenon that<strong> occurs twice every year,</strong> once in the summer and again during winter, in <strong>each hemisphere of the earth - Summer and <a href="/daily-updates/daily-news-analysis/winter-solstice#:~:text=21st%20December%20or%20the,day%2C%20in%20the%20Southern%20Hemisphere." target="_blank" rel="noopener">Winter Solstice</a>.</strong></li>
</ul>
</li>
<li><strong>About Summer Solstice:<a href="http://www.drishtiias.com/images/uploads/1624276808_image3.png" target="_blank" rel="noopener"><img class="content-img" src="http://www.drishtiias.com/images/uploads/1624276808_image3.png" style="display: block; margin-left: auto; margin-right: auto;" width="500" caption="false" /></a></strong><br />
<ul style="list-style-type: circle;">
<li>It is the<strong> longest day and shortest night</strong> of the year in the <strong>Northern Hemisphere.</strong></li>
<li>During this, <strong>countries in the Northern Hemisphere are nearest to the Sun </strong>and the <strong>Sun shines overhead on the Tropic of Cancer (23.5&deg; North).</strong><br />
<ul style="list-style-type: disc;">
<li>At latitudes of 23.5&deg; are the Tropics of Cancer and Capricorn, north and south of the Equator.</li>
<li>At 66.5&deg; are the Arctic and Antarctic Circles, to the north and south.</li>
<li>Latitudes are a measure of a location&rsquo;s distance from the Equator.</li>
</ul>
</li>
<li>During the solstice, the<strong> Earth&rsquo;s axis &mdash; around which the planet spins,</strong> completing one turn each day &mdash; is <strong>tilted in a way that the North Pole is tipped towards the sun</strong> and the South Pole is away from it.</li>
<li>Typically, this imaginary axis passes right through the middle of the Earth from top to bottom and is always<strong> tilted at 23.5 degrees with respect to the sun.</strong></li>
<li>At the<strong> Arctic Circle,</strong> the <strong>sun never sets during the solstice.</strong></li>
</ul>
</li>
<li><strong>Greater Amount of Energy:</strong><br />
<ul style="list-style-type: circle;">
<li>This day is characterised by a greater amount of energy received from the sun. According to <a href="/important-institutions/drishti-specials-important-institutions-international-institution/national-aeronautics-and-space-administration-nasa" target="_blank" rel="noopener"><strong>NASA (National Aeronautics and Space Administration)</strong></a>, the amount of incoming energy the Earth received from the sun on this day is 30% higher at the North Pole than at the Equator.</li>
<li>The maximum amount of sunlight received by the Northern Hemisphere during this time is usually on June 20, 21 or 22. In contrast, the <strong>Southern Hemisphere receives most sunlight on December 21, 22 or 23</strong> when the northern hemisphere has its longest nights&ndash; or the<strong> winter solstice.</strong></li>
</ul>
</li>
<li><strong>Geography Behind:</strong><br />
<ul style="list-style-type: circle;">
<li>The <strong>reason behind the changing lengths of the days </strong>is the<strong> Earth&rsquo;s tilt.</strong></li>
<li>The Earth&rsquo;s axis of rotation is tilted at an angle of 23.5&deg; to its orbital plane. This tilt, <strong>combined with factors such as Earth&rsquo;s spin and orbit,</strong> leads to variations in the duration of sunlight, due to which any location on the planet receives different lengths of days.<br />
<ul style="list-style-type: disc;">
<li>The Northern Hemisphere spends half the year tilted in the direction of the Sun, getting direct sunlight during long summer days. During the other half of the year, it tilts away from the Sun, and the days are shorter.</li>
</ul>
</li>
<li>The tilt is <strong>also responsible for the different seasons on Earth.</strong> This phenomenon causes the movement of the Sun from the northern to the southern hemisphere and vice versa bringing in seasonal changes in the year.</li>
</ul>
</li>
</ul>
<div class="border-bg">
<p><strong>The Equinox</strong></p>
<ul style="list-style-type: square;">
<li><strong>Twice each year,</strong> during the equinoxes (&ldquo;equal nights&rdquo;), Earth's axis is <strong>not pointed toward our Sun, but is perpendicular to the incoming rays.</strong></li>
<li>It results in a <strong>"nearly" equal amount of daylight and darkness at all latitudes.</strong></li>
<li>The<strong> vernal or spring equinox</strong> occurs in the northern hemisphere on March 20 or 21. September 22 or 23 marks the northern hemisphere <a href="/daily-updates/daily-news-analysis/autumnal-equinox-in-northern-hemisphere#:~:text=The%20word%20equinox%20is%20derived,are%20referred%20to%20as%20Equinoxes." target="_blank" rel="noopener"><strong>autumnal or fall equinox.</strong></a></li>
</ul>
</div>
<p><a href="https://indianexpress.com/article/explained/summer-solstice-explained-why-june-21-will-be-the-longest-day-of-the-year-in-northern-hemisphere-7367636/" target="_blank" rel="noopener"><strong>Source: IE</strong></a></p>',
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	(int) 7 => object(Cake\ORM\Entity) {

		'article_id' => (int) 8614,
		'category_id' => (int) 21,
		'title' => 'Early Southwest Monsoon',
		'description' => '<h3>Why in News</h3>
<p>After arriving at the Kerala Coast two days behind the schedule, the Southwest Monsoon has hit early across some areas of south peninsular and central India.</p>
<h3>Key Points</h3>
<ul style="list-style-type: square;">
<li><strong>Cause of Early Monsoon:</strong><br />
<ul style="list-style-type: circle;">
<li><a href="/daily-updates/daily-news-analysis/cyclone-yaas#:~:text=The%20cyclone%20has%20been%20named,(October%20to%20December)%20periods." target="_blank" rel="noopener"><strong>Cyclone Yaas</strong></a>, formed in the Bay of Bengal in May, helped in bringing the crucial southwest monsoon winds over the Andaman Sea..<br />
<ul style="list-style-type: disc;">
<li>As a rule-of-thumb, the monsoon makes its onset over Kerala roughly ten days after it makes its advent over the south Andaman sea.</li>
</ul>
</li>
<li>After delaying in Kerala, <strong>fast progress was mainly due to strong westerly winds from the Arabian</strong> Sea, and also the<strong> formation of a low-pressure system over the North Bay of Bengal</strong>, that currently lies over <strong>eastern Uttar Pradesh and Bihar.</strong></li>
<li>An <strong>off-shore trough</strong>, prevailing <strong>between Maharashtra and Kerala</strong>, has helped the monsoon arrive early over Karnataka, Goa, Andhra Pradesh, Telangana, Maharashtra and southern Gujarat.</li>
</ul>
</li>
<li><strong>Further Progress:</strong><br />
<ul style="list-style-type: circle;">
<li>Over <strong>Northwest India</strong>, the monsoon becomes <strong>active only when the monsoon currents</strong> - either from the Arabian Sea or the Bay of Bengal - reach the region. As it is not expected to happen soon, the monsoon progress will remain slow.</li>
<li>Also, a stream of <strong>mid-latitude westerly winds</strong> is approaching Northwest India, which will <strong>hinder the monsoon advancement</strong> in the immediate coming days.</li>
</ul>
</li>
<li><strong>Early Monsoon and Rainfall Quantum:</strong><br />
<ul style="list-style-type: circle;">
<li>The<strong> time of monsoon onset over a region has no direct impact on the rainfall quantum</strong> received during the season, or in the monsoon&rsquo;s progress.</li>
<li>For instance, <strong>the monsoon took 42 days in 2014 and 22 days in 2015</strong> to cover the entire country. Even with such distinct ranges, <strong>India recorded deficient rainfall during both years.</strong></li>
</ul>
</li>
<li><strong>Impact on Summer-Sown Crops:</strong><br />
<ul style="list-style-type: circle;">
<li>The early arrival of monsoon rains in central and northern India will help farmers accelerate sowing of <a href="/to-the-points/paper3/cropping-patterns-and-major-crops-of-india-part-one" target="_blank" rel="noopener"><strong>summer-sown crops</strong></a> such as paddy rice, cotton, soybean and pulses, and may boost crop yields too.</li>
</ul>
</li>
<li><strong>Indications of Climate Change:</strong><br />
<ul style="list-style-type: circle;">
<li>The onset of the monsoon over various parts of the country each year can be ahead of time, in time or late. These variations are generally considered normal, given the complexity of the monsoon.</li>
<li>However, climate experts have linked <strong>extreme weather events like intense rainfall over a region within a short time span or prolonged dry spell</strong> during the four months (June-September) as indications of climate change.</li>
</ul>
</li>
</ul>
<h3>Monsoon in India</h3>
<ul style="list-style-type: square;">
<li><strong>About:</strong><br />
<ul style="list-style-type: circle;">
<li>The <strong>climate of India</strong> is described as the <strong>&lsquo;monsoon&rsquo;</strong> type. In Asia, this type of climate is found mainly in the south and the southeast.</li>
<li>Out of a total of <strong>4 seasonal divisions</strong> of India, <a href="/to-the-points/paper1/monsoon-2" target="_blank" rel="noopener"><strong>monsoon</strong> </a>occupies 2 divisions, namely:<br />
<ul style="list-style-type: disc;">
<li><strong>The southwest monsoon season</strong> - Rainfall received from the southwest monsoons is seasonal in character, which occurs between June and September.</li>
<li><strong>The retreating monsoon season</strong> - The months of October and November are known for retreating monsoons.</li>
</ul>
</li>
</ul>
</li>
<li><strong>Factors Influencing South-West Monsoon Formation:</strong><br />
<ul style="list-style-type: circle;">
<li><strong>The differential heating and cooling of land and water</strong> creates a low pressure on the landmass of India while the seas around experience comparatively high pressure.</li>
<li><strong>The shift of the position of Inter Tropical Convergence Zone (ITCZ)</strong> in summer, over the Ganga plain (this is the equatorial trough normally positioned about 5&deg;N of the equator. It is also known as the monsoon-trough during the monsoon season).</li>
<li><strong>The presence of the high-pressure area</strong>, east of Madagascar, approximately at <strong>20&deg;S over the Indian Ocean.</strong> The intensity and position of this high-pressure area affect the Indian Monsoon.</li>
<li><strong>The Tibetan plateau gets intensely heated</strong> during summer, which results in strong vertical air currents and the formation of low pressure over the plateau at about 9 km above sea level.</li>
<li><strong>The movement of the westerly jet stream</strong> to the north of the Himalayas and the presence of the <strong>tropical easterly jet stream</strong> over the Indian peninsula during summer.</li>
<li><strong>Tropical Easterly Jet</strong> (African Easterly Jet).</li>
<li><strong><a href="/to-the-points/paper1/el-nino-and-la-nina" target="_blank" rel="noopener">El Nino/Southern Oscillation (SO)</a>:</strong> Normally when the tropical eastern south Pacific Ocean experiences high pressure, the tropical eastern Indian Ocean experiences low pressure. But in certain years, there is a reversal in the pressure conditions and the eastern Pacific has lower pressure in comparison to the eastern Indian Ocean. This periodic change in pressure conditions is known as the SO.</li>
</ul>
</li>
</ul>
<p><a href="https://indianexpress.com/article/explained/southwest-monsoon-rainfall-season-kerala-coast-7360834/" target="_blank" rel="noopener"><strong>Source: IE</strong></a></p>',
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	(int) 8 => object(Cake\ORM\Entity) {

		'article_id' => (int) 8530,
		'category_id' => (int) 21,
		'title' => 'Black Carbon and Glacier Melting',
		'description' => '<h3>Why in News</h3>
<p>The report titled <strong>&ldquo;Glaciers of the Himalayas: Climate Change, Black Carbon and Regional Resilience&rdquo;</strong> says that the <a href="/to-the-points/paper1/glaciers-6" target="_blank" rel="noopener"><strong>glaciers</strong></a> are melting faster than the global average ice mass. However, the strong policy on <a href="/daily-updates/daily-news-analysis/concentration-of-black-carbon-on-gangotri-glacier" target="_blank" rel="noopener"><strong>black carbon</strong></a> can sharply cut glacier melt.</p>
<ul style="list-style-type: square;">
<li>The research report is <strong>released by the <a href="/important-institutions/drishti-specials-important-institutions-international-institution/world-bank-group" target="_blank" rel="noopener">World Bank</a></strong> and covers the <strong><a href="/daily-updates/daily-news-analysis/national-mission-on-sustaining-himalayan-ecosystem" target="_blank" rel="noopener">Himalaya</a>, Karakoram</strong>, and <a href="/daily-updates/daily-news-analysis/hindu-kush-himalayan-region" target="_blank" rel="noopener"><strong>Hindu Kush (HKHK)</strong></a> mountain ranges.</li>
</ul>
<div class="border-bg">
<p><strong>Black Carbon</strong></p>
<ul style="list-style-type: square;">
<li>Black carbon is <strong>a kind of an aerosol.</strong> <br />
<ul style="list-style-type: circle;">
<li>An <strong>aerosol</strong> is a suspension of fine solid particles or liquid droplets in the air.</li>
</ul>
</li>
<li>Among aerosols (such as brown carbon, sulphates), Black Carbon (BC) has been <strong>recognized as the second most important anthropogenic agent for climate change</strong> and the <strong>primary marker to understand the adverse effects caused by air pollution.</strong></li>
<li>It <strong>gets emitted</strong> from gas and diesel engines, coal-fired power plants, and other sources that burn fossil fuel. It <strong>comprises a significant portion of <a href="/daily-updates/daily-news-analysis/dashboard-for-monitoring-air-quality" target="_blank" rel="noopener">particulate matter or PM</a></strong>, which is an air pollutant.</li>
</ul>
<p><strong>HKHK Mountain Region:</strong></p>
<ul style="list-style-type: square;">
<li>HKHK Region <strong>spans eight countries</strong>; Afghanistan, Pakistan, India, Nepal, China, Bhutan, Bangladesh and Myanmar and also <strong>has some of the world&rsquo;s tallest mountains including <a href="/daily-updates/daily-news-analysis/new-height-for-mount-everest" target="_blank" rel="noopener">Mt. Everest</a> and K2.</strong></li>
<li>HKHK Glaciers <strong>feed into river systems</strong> including Ganga, Yangtze, Irrawaddy, and Mekong.<br />
<ul style="list-style-type: circle;">
<li>The water that runs down from glaciers <strong>feeds the agriculture</strong>, on which nearly 2 billion people are dependent upon.</li>
</ul>
</li>
<li>HKHK Region, also known as the <strong>third pole</strong>, along with China&rsquo;s Tien Shan Mountains holds most ice outside the North and the South Pole.</li>
</ul>
</div>
<h3>Key Points</h3>
<ul style="list-style-type: square;">
<li><strong>About Black Carbon:</strong><br />
<ul style="list-style-type: circle;">
<li>BC is a <strong>short-lived pollutant</strong> that is the <strong>second-largest contributor to warming the planet behind carbon dioxide (CO<sub>2</sub>).</strong> <br />
<ul style="list-style-type: disc;">
<li>Unlike other greenhouse gas emissions, BC is <strong>quickly washed out and can be eliminated from the atmosphere if emissions stop.</strong></li>
<li>Unlike historical carbon emissions it is <strong>also a localised source with greater local impact.</strong></li>
</ul>
</li>
</ul>
</li>
<li><strong>Source of Black Carbon in Himalayan Region:</strong> <br />
<ul style="list-style-type: circle;">
<li><strong>Industry</strong> (primarily brick kilns) and <strong>residential burning of solid fuel</strong> together account for 45-66% of regional anthropogenic (man-made) BC deposition, followed by <strong>on-road diesel fuels</strong> (7-18%) and <strong>open burning</strong> (less than 3% in all seasons) in the region.</li>
</ul>
</li>
<li><strong>Impact of Deposits of BC:</strong> <br />
<ul style="list-style-type: circle;">
<li>It <strong>acts in two ways</strong> hastening the pace of glacier melt:<br />
<ul style="list-style-type: disc;">
<li>By decreasing surface reflectance of sunlight.</li>
<li>By raising the air temperature.</li>
</ul>
</li>
</ul>
</li>
<li><strong>Rate of De-glaciation:</strong> <br />
<ul style="list-style-type: circle;">
<li>The rate of retreat of HKHK glaciers is <strong>estimated to be 0.3 metres per year in the west to 1.0 metre per year</strong> in the east.</li>
<li>Full implementation of <strong>current policies to mitigate BC can achieve a 23% reduction</strong> but <strong>enacting new policies</strong> and incorporating them through regional cooperation among countries can achieve enhanced benefits.<br />
<ul style="list-style-type: disc;">
<li><strong>National Mission on Sustaining Himalayan Ecosystem (NMSHE)</strong> is one such policy adopted in India. It is one of the eight missions under the <strong><a href="/to-the-points/Paper2/national-action-plan-on-climate-change" target="_blank" rel="noopener">National Action Plan on Climate Change (NAPCC)</a>.</strong></li>
</ul>
</li>
<li><strong>BC deposits can be sharply reduced</strong> through new, currently feasible policies <strong>by an additional 50%</strong> from current levels.</li>
</ul>
</li>
<li><strong>Impact of Glacier Melt:</strong><br />
<ul style="list-style-type: circle;">
<li>Glacier melt <strong>produces <a href="/daily-updates/daily-news-analysis/uttarakhand-flash-flood" target="_blank" rel="noopener">flash floods</a>, landslips, <a href="/daily-updates/daily-news-analysis/India%20lost%20One-Third%20of%20its%20Coastline%20Due%20to%20Soil%20Erosion" target="_blank" rel="noopener">soil erosion</a>, and <a href="/daily-updates/daily-news-analysis/himalayan-glaciers-impacted-by-climate-change" target="_blank" rel="noopener">glacial lake outburst floods (GLOF)</a>.</strong></li>
<li>In the short run, the higher volumes of melt water <strong>could replace receding groundwater downstream.</strong> But in the long run, decreased water availability would <strong>aggravate water shortage.</strong></li>
</ul>
</li>
<li><strong>Measures to be Taken:</strong><br />
<ul style="list-style-type: circle;">
<li>In the Himalayas, <strong>reducing black carbon emissions from cookstoves, diesel engines, and open burning</strong> would have the greatest impact and could significantly <strong>reduce radiative forcing</strong> and help to maintain a greater portion of Himalayan glacier systems. <br />
<ul style="list-style-type: disc;">
<li><strong>Radiative forcing is a measure of the change in energy balance</strong> as a result of a change in a forcing agent (e.g., greenhouse gases, aerosol, cloud, and surface albedo) to affect the global energy balance and contribute to climate change.</li>
</ul>
</li>
</ul>
</li>
<li><strong>Steps to be Taken by Regional Governments:</strong><br />
<ul style="list-style-type: circle;">
<li>Review the <strong>policies on water management</strong>, with an emphasis on basin-based regulation and use of price signals (value of a particular action) for efficiency.</li>
<li>Careful <strong>planning and use of hydropower</strong> to reflect changes in water flows and availability.</li>
<li>Increasing the <strong>efficiency of brick kilns</strong> through proven technologies.</li>
<li>There must also be greater <strong>knowledge sharing</strong> in the region.</li>
</ul>
</li>
</ul>
<p><a href="https://www.thehindu.com/sci-tech/energy-and-environment/strong-policies-on-black-carbon-can-sharply-cut-glacier-melt-says-world-bank-study/article34719913.ece/amp/" target="_blank" rel="noopener"><strong>Source: TH</strong></a></p>',
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	(int) 9 => object(Cake\ORM\Entity) {

		'article_id' => (int) 8481,
		'category_id' => (int) 21,
		'title' => 'Cyclone Yaas',
		'description' => '<h3>Why in News</h3>
<p>Recently, cyclone <strong>Yaas</strong> made landfall south of <strong>Balasore in Odisha.</strong></p>
<ul style="list-style-type: square;">
<li>Earlier, another <strong>cyclonic storm named <a href="/daily-updates/daily-news-analysis/cyclone-tauktae" target="_blank" rel="noopener">&lsquo;Cyclone Tauktae&rsquo;</a></strong> had affected the Indian states of Kerala, Gujarat, Maharashtra, Goa and Karnataka, along with two Union Territories: Daman &amp; Diu and Lakshadweep.</li>
</ul>
<h3>Key Points</h3>
<ul style="list-style-type: square;">
<li><strong>About:</strong><br />
<ul style="list-style-type: circle;">
<li>The cyclone has been <strong>named Yaas by Oman.</strong> The word Yaas has originated from the Persian language and means <strong>&lsquo;Jasmin&rsquo;</strong> in English.</li>
<li>Typically, <strong>tropical cyclones in the North Indian Ocean region</strong> (Bay of Bengal and Arabian Sea) <strong>develop during the pre-monsoon</strong> (April to June) and <strong>post-monsoon</strong> (October to December) periods.<br />
<ul style="list-style-type: disc;">
<li><strong>May-June</strong> and <strong>October-November</strong> are known to produce cyclones of severe intensity that affect the Indian coasts.</li>
</ul>
</li>
</ul>
</li>
<li><strong>Classification:</strong><br />
<ul style="list-style-type: circle;">
<li>It has been classified as a<strong> very severe cyclone.</strong></li>
<li>The <a href="https://www.thehindu.com/news/national/cyclone-yaas-makes-landfall-in-balasore-triggers-heavy-damage/article34652295.ece" target="_blank" rel="noopener"><strong>India Meteorological Department (IMD)</strong></a> classifies cyclones on the <strong>basis of the maximum sustained surface wind speed</strong> (MSW) they generate.<br />
<ul style="list-style-type: disc;">
<li>The cyclones are classified as<strong> severe</strong> (MSW of 48-63 knots),<strong> very severe</strong> (MSW of 64-89 knots), <strong>extremely severe</strong> (MSW of 90-119 knots) and <strong>super cyclonic storm</strong> (MSW of 120 knots or more).</li>
</ul>
</li>
</ul>
</li>
<li><strong>Areas Affected:</strong><br />
<ul style="list-style-type: circle;">
<li>It affected the <strong>bordering regions of West Bengal and Odisha</strong> and weakened into a cyclonic storm, leaving behind a<strong> trail of destruction on the eastern coast.</strong></li>
</ul>
</li>
<li><strong>Bay of Bengal Getting Warmer:</strong>
<ul style="list-style-type: circle;">
<li>The Bay of Bengal, where cyclone Yaas has formed, is at least <strong>two degrees warmer than what is normal for this time of the year.</strong></li>
<li>The north Bay of Bengal is exceptionally warm with temperatures up to 32 degrees.<strong></strong></li>
</ul>
</li>
<li><strong>Tropical Cyclones:</strong><br />
<ul style="list-style-type: circle;">
<li>A <a href="/to-the-points/paper1/cyclone-19" target="_blank" rel="noopener"><strong>tropical cyclone</strong></a> is an<strong> intense circular storm that originates over warm tropical oceans</strong> and is characterized by low atmospheric pressure, high winds, and heavy rain.</li>
<li>A<strong> characteristic feature of tropical cyclones is the eye,</strong> a central region of clear skies, warm temperatures, and low atmospheric pressure.</li>
<li>Storms of this type are called <strong>hurricanes in the North Atlantic and eastern Pacific and typhoons in SouthEast Asia and China.</strong> They are called<strong> tropical cyclones in the southwest Pacific and Indian Ocean region and Willy-willies in north-western Australia.</strong></li>
<li>Storms <strong>rotate counterclockwise in the northern hemisphere </strong>and <strong>clockwise in the southern hemisphere.</strong></li>
<li>The <strong>conditions favourable</strong> for the formation and intensification of tropical storms are:<br />
<ul style="list-style-type: disc;">
<li><strong>Large sea surface</strong> with temperature higher than 27&deg; C.</li>
<li>Presence of the <strong><a href="/mains-practice-question/question-31" target="_blank" rel="noopener">Coriolis force</a>.</strong></li>
<li>Small <strong>variations in the vertical wind speed.</strong></li>
<li>A pre-existing <strong>weak low- pressure area</strong> or low-level-cyclonic circulation.</li>
<li>Upper <strong>divergence</strong> above the sea level system.</li>
</ul>
</li>
</ul>
</li>
</ul>
<p><a href="http://www.drishtiias.com/images/uploads/1622281357_image2.png" target="_blank" rel="noopener"><img class="content-img" src="http://www.drishtiias.com/images/uploads/1622281357_image2.png" style="display: block; margin-left: auto; margin-right: auto;" width="750" caption="false" /></a></p>
<ul style="list-style-type: square;">
<li><strong>Naming of Tropical Cyclones:</strong><br />
<ul style="list-style-type: circle;">
<li>According to <a href="https://www.thehindu.com/news/national/cyclone-yaas-makes-landfall-in-balasore-triggers-heavy-damage/article34652295.ece" target="_blank" rel="noopener"><strong>WMO (World Meteorological Organization)</strong></a> guidelines, countries in every region are supposed to give names for cyclones.</li>
<li>The <strong>North Indian Ocean Region</strong> covers tropical cyclones formed over Bay of Bengal and Arabian Sea.</li>
<li>The 13 members, which come under the region, are <strong>Bangladesh, India, Maldives, Myanmar, Oman, Pakistan, Sri Lanka, Thailand, Iran, Qatar, Saudi Arabia, the UAE and Yemen.</strong></li>
<li>IMD, one of the six <strong>Regional Specialised Meteorological Centres (RSMC)</strong> in the world, is mandated to issue advisories and name tropical cyclones in the north Indian Ocean Region.<br />
<ul style="list-style-type: disc;">
<li>It is an agency of the <strong>Ministry of Earth Sciences.</strong></li>
</ul>
</li>
</ul>
</li>
</ul>
<div class="border-bg">
<p><strong>Bay of Bengal vs Arabian Sea (Cyclones)</strong></p>
<ul style="list-style-type: square;">
<li><strong>Bay of Bengal:</strong><br />
<ul style="list-style-type: circle;">
<li>As it is <strong>concave or shallow where when strong winds push water, it gets concentrated as a storm.</strong></li>
<li>It is <strong>shaped like a trough that makes it more hospitable for storms</strong> to gain force. Moreover, the <strong>high sea surface temperature makes matters more worse</strong> in the Bay triggering the intensity of the storms.</li>
<li>Additionally, it <strong>gets more rainfall</strong> with sluggish winds and warm air currents around it that keep temperatures relatively high all year. The <strong>constant inflow of fresh warm water from the perennial rivers</strong> like Brahmaputra, Ganga makes it further impossible to mix with the cooler water below.</li>
<li><strong>Lack of landmass between the Pacific Ocean and the Bay of Bengal</strong> tend cyclonic winds to move into the coastal areas causing heavy rainfall.</li>
<li>The <strong>absence of air movements from north-western India towards the Bay in the post-monsoon phase is also another reason</strong> for the chances of cyclones in the Bay of Bengal.</li>
</ul>
</li>
<li><strong>Arabian Sea:</strong><br />
<ul style="list-style-type: circle;">
<li>It is much <strong>calmer</strong> as the<strong> stronger winds help dissipate the heat and lack of constant fresh water</strong> helps the warm water to mix with the cool water underneath, reducing the surface temperature.</li>
<li>The Arabian Sea enjoys the <strong>locational advantage</strong> as the winds from the Pacific Ocean encounter the Western Ghats and the Himalayas cutting down on its intensity and sometimes never reaching the Arabian Sea.</li>
</ul>
</li>
</ul>
<p><a href="http://www.drishtiias.com/images/uploads/1622281491_image4.jpg" target="_blank" rel="noopener"><img class="content-img" src="http://www.drishtiias.com/images/uploads/1622281491_image4.jpg" style="display: block; margin-left: auto; margin-right: auto;" width="500" caption="false" /></a></p>
</div>
<p><a href="https://www.thehindu.com/news/national/cyclone-yaas-makes-landfall-in-balasore-triggers-heavy-damage/article34652295.ece" target="_blank" rel="noopener"><strong>Source: TH</strong></a></p>',
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	(int) 10 => object(Cake\ORM\Entity) {

		'article_id' => (int) 8457,
		'category_id' => (int) 21,
		'title' => 'Total Lunar Eclipse and Supermoon',
		'description' => '<h3>Why in News</h3>
<p>Two celestial events -<strong> Total Lunar Eclipse and Supermoon -</strong> together coincide on 26<sup>th</sup> May 2021.</p>
<h3>Key Points</h3>
<ul style="list-style-type: square;">
<li><strong>Supermoon:</strong><br />
<ul style="list-style-type: circle;">
<li>A supermoon <strong>occurs when the Moon&rsquo;s orbit is closest to the Earth</strong> at the same time that the <strong>Moon is full.</strong><br />
<ul style="list-style-type: disc;">
<li>As the <strong>Moon orbits the Earth,</strong> there is a point of time when the <strong>distance between the two is the least</strong> (called the <strong>perigee</strong>) and a point of time when the <strong>distance is the most</strong> (called the <strong>apogee</strong>).</li>
</ul>
</li>
<li>Since a <strong>full Moon</strong> appears at the point of <strong>least distance</strong> from<strong> earth,</strong> not only does it appear to be<strong> brighter</strong> but it is also<strong> larger than a regular full moon.</strong></li>
<li>According to NASA, the term supermoon was <strong>coined by astrologer Richard Nolle in 1979.</strong> In a typical year, there may be two to four full supermoons and two to four new supermoons in a row.</li>
</ul>
</li>
</ul>
<p><a href="http://www.drishtiias.com/images/uploads/1622024695_image1.jpg" target="_blank" rel="noopener"><img class="content-img" src="http://www.drishtiias.com/images/uploads/1622024695_image1.jpg" style="display: block; margin-left: auto; margin-right: auto;" width="350" caption="false" /></a></p>
<ul style="list-style-type: square;">
<li><strong>Lunar Eclipse:</strong><br />
<ul style="list-style-type: circle;">
<li><strong>About:</strong><br />
<ul style="list-style-type: disc;">
<li>Lunar eclipse<strong> takes place when the Moon moves into the Earth&rsquo;s shadow.</strong> The<strong> Earth has to be directly between the Sun and the Moon,</strong> and a lunar eclipse can <strong>only</strong> take place during <strong>a full Moon.</strong></li>
<li>First, the Moon moves into the<strong> penumbra &ndash;</strong> the part of the Earth&rsquo;s shadow where not all of the light from the Sun is blocked out. Part of the Moon&rsquo;s disc will look dimmer than a regular full Moon.</li>
<li>And then the Moon moves into the Earth&rsquo;s<strong> umbra,</strong> where direct light from the Sun is totally blocked out by the Earth. This means the only light reflecting off the Moon&rsquo;s disc has already been refracted, or bent, by the Earth&rsquo;s atmosphere.</li>
</ul>
</li>
<li><strong>Total Lunar Eclipse:</strong><br />
<ul style="list-style-type: disc;">
<li>During this, the whole of the <strong>lunar disc</strong> enters the <strong>Earth&rsquo;s umbra,</strong> so the <strong>Moon appears reddish (Blood Moon).</strong> This won&rsquo;t last forever, though.</li>
<li>After about 14 minutes, the <strong>Moon will move out of Earth&rsquo;s umbra</strong> and back into its<strong> penumbra.</strong> In <strong>total, the lunar eclipse</strong> will last a few hours.</li>
<li><strong>Red light</strong> has a <strong>longer wavelength</strong> than<strong> blue light,</strong> which gives the <strong>lunar eclipse</strong> its characteristic<strong> reddish colour.</strong> <br />
<ul style="list-style-type: disc;">
<li>On Earth, we see the same effect <strong>during sunrises and sunsets,</strong> when the sky has a more reddish glow than during the day.</li>
</ul>
</li>
</ul>
</li>
</ul>
</li>
</ul>
<p><a href="http://www.drishtiias.com/images/uploads/1622024836_image2.jpg" target="_blank" rel="noopener"><img class="content-img" src="http://www.drishtiias.com/images/uploads/1622024836_image2.jpg" style="display: block; margin-left: auto; margin-right: auto;" width="500" caption="false" /></a></p>
<div class="border-bg">
<p><strong>Total Solar Eclipse</strong></p>
<ul style="list-style-type: square;">
<li><strong>Total <a href="/daily-updates/daily-news-analysis/total-solar-eclipse-2019" target="_blank" rel="noopener">solar eclipses</a></strong> occur when the <strong>New Moon comes between the Sun and Earth</strong> and casts the darkest part of its shadow, the umbra, on Earth.<strong> A full solar eclipse,</strong> known as totality, is <strong>almost as dark</strong> as night.</li>
<li>During <strong>a total eclipse</strong> of the Sun, the Moon covers the <strong>entire disk of the Sun.</strong> In partial and annular solar eclipses, the Moon blocks only part of the Sun.</li>
<li>When the Moon completely <strong>covers the disk</strong> of the Sun, only the <strong>Sun's corona is visible.</strong></li>
<li>It is <strong>called Total eclipse</strong> because at the maximum point of the eclipse (midpoint of time of totality), the sky goes dark and<strong> temperatures can fall.</strong></li>
</ul>
<p><a href="http://www.drishtiias.com/images/uploads/1622024976_image4.jpg" target="_blank" rel="noopener"><strong><img class="content-img" src="http://www.drishtiias.com/images/uploads/1622024976_image4.jpg" width="500" caption="false" style="display: block; margin-left: auto; margin-right: auto;" /></strong></a></p>
</div>
<p><a href="https://indianexpress.com/article/explained/total-lunar-eclipse-supermoon-may-26-explained-7329540/" target="_blank" rel="noopener"><strong>Source: IE</strong></a></p>',
		'posturl' => 'total-lunar-eclipse-and-supermoon',
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	(int) 11 => object(Cake\ORM\Entity) {

		'article_id' => (int) 8390,
		'category_id' => (int) 21,
		'title' => 'Cyclone Tauktae',
		'description' => '<h3>Why in News</h3>
<p>Recently, <strong>Cyclone Tauktae</strong> made landfall in <strong>Gujarat.</strong></p>
<ul style="list-style-type: square;">
<li>The cyclone has left a trail of destruction as it swept through the coastal states of <strong>Kerala, Karnataka, Goa and Maharashtra.</strong></li>
</ul>
<h3>Key Points</h3>
<ul style="list-style-type: square;">
<li><strong>About:</strong><br />
<ul style="list-style-type: circle;">
<li><strong>Named by:</strong><br />
<ul style="list-style-type: disc;">
<li>It is<strong> a tropical cyclone, named by Myanmar.</strong> It means 'gecko', a highly vocal lizard, in the Burmese language.</li>
<li>Typically, <strong>tropical cyclones</strong> in the North Indian Ocean region<strong> (Bay of Bengal and Arabian Sea)</strong> develop during the <strong>pre-monsoon</strong> (April to June) and <strong>post-monsoon</strong> (October to December) periods. <br />
<ul style="list-style-type: disc;">
<li><strong>May-June and October-November</strong> are known to produce cyclones of severe intensity that affect the Indian coasts.</li>
</ul>
</li>
</ul>
</li>
<li><strong>Classification:</strong><br />
<ul style="list-style-type: disc;">
<li>It has <strong>weakened into a "very severe cyclonic storm"</strong> from the "extremely severe cyclonic storm".</li>
<li>The <strong>India Meteorological Department (IMD) classifies cyclones on the basis of the maximum sustained surface wind speed (MSW)</strong> they generate.</li>
<li>The cyclones are classified as <strong>severe (MSW of 48-63 knots), very severe (MSW of 64-89 knots),</strong> <strong>extremely severe (MSW of 90-119 knots)</strong> and<strong> super cyclonic storm (MSW of 120 knots or more).</strong> <strong>One knot</strong> is equal to<strong> 1.8 kmph (kilometers per hour).</strong></li>
</ul>
</li>
<li><strong>Developed in Arabian Sea:</strong><br />
<ul style="list-style-type: disc;">
<li>Tauktae is the <strong>fourth cyclone in consecutive years</strong> to have developed<strong> in the Arabian Sea,</strong> that too <strong>in the pre-monsoon period (April to June).</strong></li>
<li>After <strong>Cyclone Mekanu</strong> in 2018, which struck Oman, <a href="/daily-updates/daily-news-analysis/cyclone-vayu" target="_blank" rel="noopener"><strong>Cyclone Vayu</strong></a> in 2019 struck Gujarat, followed by <a href="/daily-updates/daily-news-analysis/cyclone-nisarga" target="_blank" rel="noopener"><strong>Cyclone Nisarga</strong></a> in 2020 that struck Maharashtra.</li>
<li>All these cyclones<strong> since 2018</strong> have been categorised either<strong> &lsquo;Severe Cyclone&rsquo; or above.</strong></li>
</ul>
</li>
</ul>
</li>
<li><strong>Arabian Sea becoming Hotbed of Cyclones:</strong><br />
<ul style="list-style-type: circle;">
<li><strong>Annually, five cyclones on average</strong> form in the Bay of Bengal and the Arabian Sea combined. Of these, <strong>four develop in the Bay of Bengal, which is warmer than the Arabian Sea.</strong></li>
<li>In <strong>2018,</strong> while the Bay of Bengal maintained its average of four cyclones a year, the <strong>Arabian Sea produced three cyclonic storms.</strong> In <strong>2019,</strong> the <strong>Arabian Sea overtook</strong> the <strong>Bay of Bengal</strong> with<strong> five cyclones to three.</strong></li>
<li>In<strong> 2020,</strong> the <strong>Bay of Bengal</strong> produced <strong>three cyclonic storms</strong> while the <strong>Arabian Sea</strong> generated <strong>two.</strong></li>
<li>In recent years, meteorologists have observed that the <strong>Arabian Sea, too, has been warming.</strong> This is a phenomenon<strong> associated with global warming.</strong></li>
<li>It has been observed that the<strong> sea surface temperature in the Arabian Sea has been rising</strong> for about 40 years. The <strong>increase</strong> in temperature is in the zone<strong> of 1.2-1.4 degree Celsius.</strong></li>
</ul>
</li>
<li><strong>Tropical Cyclone:</strong><br />
<ul style="list-style-type: circle;">
<li>A tropical cyclone is <strong>an intense circular storm that originates over warm tropical oceans</strong> and is characterized by low atmospheric pressure, high winds, and heavy rain.</li>
<li>A<strong> characteristic feature</strong> of tropical cyclones is the<strong> eye,</strong> a central region of clear skies, warm temperatures, and low atmospheric pressure.</li>
<li>Storms of this type<strong> are called hurricanes</strong> in the <strong>North Atlantic and eastern Pacific </strong>and<strong> typhoons in SouthEast Asia and China.</strong> They are called <strong>tropical cyclones in the southwest Pacific and Indian Ocean</strong> region and <strong>Willy-willies</strong> in north-western <strong>Australia.</strong></li>
<li>Storms<strong> rotate counterclockwise</strong> in the <strong>northern hemisphere</strong> and<strong> clockwise in the southern</strong> hemisphere.</li>
<li>The<strong> conditions favourable</strong> for the<strong> formation and intensification</strong> of tropical storms are:<br />
<ul style="list-style-type: disc;">
<li><strong>Large sea surface</strong> with <strong>temperature higher than 27&deg; C.</strong></li>
<li>Presence of the<strong> Coriolis force.</strong></li>
<li>Small variations in the<strong> vertical wind speed.</strong></li>
<li>A pre-existing weak low-<strong> pressure area or low-level-cyclonic circulation.</strong></li>
<li><strong>Upper divergence</strong> above the sea level system.</li>
</ul>
</li>
</ul>
</li>
<li><strong>Naming of Tropical Cyclones:</strong><br />
<ul style="list-style-type: circle;">
<li>According to <strong>WMO (<a href="/daily-updates/daily-news-analysis/state-of-the-global-climate-wmo" target="_blank" rel="noopener">World Meteorological Organization</a>) guidelines,</strong> countries in every region are supposed to give names for cyclones.</li>
<li>The <strong>North Indian Ocean Region</strong> covers tropical cyclones formed over Bay of Bengal and Arabian Sea.</li>
<li>The<strong> 13 members,</strong> which come under the region, are <strong>Bangladesh, India, Maldives, Myanmar, Oman, Pakistan, Sri Lanka, Thailand, Iran, Qatar, Saudi Arabia, the UAE </strong>and <strong>Yemen.</strong></li>
<li><a href="/daily-updates/daily-news-analysis/state-of-the-climate-report-2020-imd" target="_blank" rel="noopener"><strong>India Meteorological Department (IMD)</strong></a>, one of the six <strong>Regional Specialised Meteorological Centres (RSMC)</strong> in the world, is mandated to issue advisories and name tropical cyclones in the <strong>north Indian Ocean Region.</strong><br />
<ul style="list-style-type: disc;">
<li>It is an agency of the <strong>Ministry of Earth Sciences.</strong></li>
</ul>
</li>
</ul>
</li>
</ul>
<p><a href="https://indianexpress.com/article/explained/explained-in-cyclone-tauktae-a-continuing-new-trend-from-the-arabian-sea-7317913/" target="_blank" rel="noopener"><strong>Source: IE</strong></a></p>',
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	(int) 12 => object(Cake\ORM\Entity) {

		'article_id' => (int) 8286,
		'category_id' => (int) 21,
		'title' => 'Climate Change Causing Shift in Earth’s Axis',
		'description' => '<h3>Why in News</h3>
<p>A study published in Geophysical Research Letters of the American Geophysical Union (AGU) says that <strong>due to the significant melting of glaciers</strong> because of global temperature rise, <strong>Earth&rsquo;s axis of rotation has been moving more than usual</strong> since the 1990s.</p>
<ul style="list-style-type: square;">
<li>While this change is <strong>not expected to affect daily life</strong>, it can <strong>change the length of the day by a few milliseconds.</strong></li>
</ul>
<p><a href="http://www.drishtiias.com/images/uploads/1620037413_image%20 (1).png" target="_blank" rel="noopener"><strong><img class="content-img" src="http://www.drishtiias.com/images/uploads/1620037413_image  (1).png" style="display: block; margin-left: auto; margin-right: auto;" width="350" caption="false" /></strong></a></p>
<h3>Key Points</h3>
<ul style="list-style-type: square;">
<li><strong>Earth&rsquo;s Axis of Rotation:</strong><br />
<ul style="list-style-type: circle;">
<li>It is the <strong>line along which it spins around itself</strong> as it revolves around the Sun.<br />
<ul style="list-style-type: disc;">
<li><strong>Earth's axial tilt</strong> (also known as the obliquity of the ecliptic) is about <strong>23.5 degrees.</strong> Due to this axial tilt, the sun shines on different latitudes at different angles throughout the year. This <strong>causes the seasons.</strong></li>
</ul>
</li>
<li>The <strong>points</strong> on which the <strong>axis intersects the planet&rsquo;s surface</strong> are the <strong>geographical north and south poles.</strong><br />
<ul style="list-style-type: disc;">
<li>The <strong>location of the poles is not fixed.</strong> The <strong>axis moves</strong> due to <strong>changes in how the Earth&rsquo;s mass is distributed</strong> around the planet. Thus, the <strong>poles move when the axis moves</strong>, and the movement is called <strong>&ldquo;polar motion&rdquo;.</strong></li>
<li>Generally, polar motion is <strong>caused by</strong> changes in the hydrosphere, atmosphere, oceans, or solid Earth. But now, climate change is adding to the degree with which the poles wander.</li>
</ul>
</li>
<li>According to NASA, data from the <strong>20<sup>th</sup> century</strong> shows that the <strong>spin axis drifted about 10 centimetres per year.</strong> Meaning over a century, <strong>polar motion exceeds 10 metres.</strong></li>
</ul>
</li>
<li><strong>Findings from the New Study:</strong><br />
<ul style="list-style-type: circle;">
<li>Since the <strong>1990s, climate change has caused billions of tonnes of glacial ice to melt</strong> into oceans. This has <strong>caused the Earth&rsquo;s poles to move in new directions.</strong></li>
<li>The <strong>north pole has shifted in a new eastward direction</strong> since the 1990s, <strong>because of changes in the hydrosphere</strong> (meaning the way in which water is stored on Earth).</li>
<li>From 1995 to 2020, the average speed of drift was <strong>17 times faster</strong> than from 1981 to 1995.</li>
<li>Also, in the last four decades, the <strong>poles moved by about 4 metres in distance.</strong></li>
<li>The calculations were based on satellite data from <strong>NASA&rsquo;s Gravity Recovery and Climate Experiment (GRACE) mission.</strong></li>
<li><strong>Causes of Polar Drift:</strong><br />
<ul style="list-style-type: disc;">
<li><strong>Ice Melting:</strong><br />
<ul style="list-style-type: disc;">
<li>The faster ice melting under global warming was the most likely cause of the directional change of the polar drift in the 1990s.</li>
<li>As glaciers melt, water mass redistributes, causing shifts in the planet's axis.</li>
</ul>
</li>
<li><strong>Change in Non-Glacial Regions (Terrestrial Water Storage):</strong><br />
<ul style="list-style-type: disc;">
<li>Due to climate change and unsustainable consumption of groundwater for irrigation and other anthropogenic activities.</li>
</ul>
</li>
<li><strong>Groundwater Depletion:</strong><br />
<ul style="list-style-type: disc;">
<li>As millions of tonnes of water from below the land is pumped out every year for drinking, industries or agriculture, most of it eventually joins the sea, thus redistributing the planet&rsquo;s mass.</li>
</ul>
</li>
</ul>
</li>
</ul>
</li>
</ul>
<p><a href="https://indianexpress.com/article/explained/explained-what-new-research-says-about-climate-change-causing-a-shift-in-earths-axis-7299258/" target="_blank" rel="noopener"><strong>Source: IE</strong></a></p>',
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	(int) 13 => object(Cake\ORM\Entity) {

		'article_id' => (int) 8187,
		'category_id' => (int) 21,
		'title' => 'Sulphur Dioxide Emissions from Caribbean Volcano ',
		'description' => '<h3>Why in News</h3>
<p>The <a href="/daily-updates/daily-news-analysis/sulfur-dioxide-emission-norms-delayed#:~:text=India%27s%20sulphur%20dioxide%20(SO2,largest%20emitter%20of%20SO2." target="_blank" rel="noopener"><strong>Sulphur Dioxide (SO<sub>2</sub>) emissions</strong></a> <strong>from a <a href="/daily-updates/daily-news-analysis/sangay-volcano-ecuador" target="_blank" rel="noopener">volcanic eruption</a> in the Caribbean (La Soufriere Volcano)</strong> have reached India, sparking fear of <strong>increased <a href="/daily-updates/daily-news-editorials/air-pollution-concerted-efforts" target="_blank" rel="noopener">pollution</a> levels</strong> in the northern parts of the country and <strong>acid rain.</strong></p>
<ul style="list-style-type: square;">
<li>The <strong>Caribbean is the region</strong> roughly south of the United States, east of Mexico and north of Central and South America, consisting of the Caribbean Sea and its islands.</li>
</ul>
<h3>Key Points</h3>
<ul style="list-style-type: square;">
<li><strong>About La Soufriere Volcano:</strong><br />
<ul style="list-style-type: circle;">
<li>It is <strong>an active stratovolcano</strong> on the <strong>Caribbean island of Saint Vincent</strong> in Saint Vincent and the Grenadines.<br />
<ul style="list-style-type: disc;">
<li>A <strong>stratovolcano</strong> is a tall, conical volcano composed of one layer of hardened lava, tephra, and volcanic ash. These volcanoes are characterized by a steep profile and periodic, explosive eruptions.</li>
<li>Saint Vincent and the Grenadines, <strong>located in the southern Caribbean</strong>, consists of more than 30 islands and cays, nine of which are inhabited.</li>
</ul>
</li>
<li>It is the <strong>highest peak in Saint Vincent</strong> and has had five recorded explosive eruptions since 1718, most recently in April 2021.<br />
<ul style="list-style-type: disc;">
<li>The last time the volcano had <strong>erupted was in 1979.</strong></li>
</ul>
</li>
</ul>
</li>
</ul>
<p><a href="http://www.drishtiias.com/images/uploads/1618901971_image%202.jpg" target="_blank" rel="noopener"><strong><img class="content-img" src="http://www.drishtiias.com/images/uploads/1618901971_image 2.jpg" width="450" caption="false" style="display: block; margin-left: auto; margin-right: auto;" /></strong></a></p>
<ul style="list-style-type: square;">
<li><strong>Impact of the Eruption on Global Temperatures:</strong><br />
<ul style="list-style-type: circle;">
<li><strong>Volcanic emissions</strong> reaching the stratosphere <strong>can have a cooling effect on global temperatures.</strong></li>
<li>The most significant climate impacts from volcanic injections into the stratosphere come from the <strong>conversion of sulphur dioxide</strong> to <strong>sulphuric acid</strong>, which condenses rapidly in the stratosphere to form <strong>fine sulphate aerosols.</strong><br />
<ul style="list-style-type: disc;">
<li>The <strong>aerosols increase</strong> the <strong>reflection of radiation</strong> from the Sun back into space, <strong>cooling the Earth&rsquo;s</strong> lower atmosphere or troposphere.</li>
<li>Bigger eruptions during the past century have caused a decrease in temperature of <strong>0.27 degree Celsius</strong> or more on the Earth&rsquo;s surface for up to three years.</li>
</ul>
</li>
</ul>
</li>
<li><strong>Sulphur Dioxide and Pollution:</strong><br />
<ul style="list-style-type: circle;">
<li>SO<sub>2</sub> emissions that lead to high concentrations of SO<sub>2</sub> in the air generally also lead to the formation of other sulfur oxides (SO<sub>x</sub>). SO<sub>x</sub> can react with other compounds in the atmosphere to form small particles. These particles contribute to <strong><a href="/daily-updates/daily-news-analysis/dashboard-for-monitoring-air-quality" target="_blank" rel="noopener">Particulate Matter (PM)</a> pollution.</strong></li>
<li>Small particles may penetrate deeply into the lungs and in sufficient quantities can contribute to health problems.</li>
</ul>
</li>
<li><strong>Sulphur Dioxide and Acid Rain:</strong><br />
<ul style="list-style-type: circle;">
<li>Acid rain results <strong>when sulphur dioxide (SO<sub>2</sub>) and nitrogen oxides (NO<sub>X</sub>) are emitted into the atmosphere</strong> and transported by wind and air currents.</li>
<li>The <strong>SO<sub>2</sub> and NO<sub>X</sub> react with water, oxygen and other chemicals</strong> to form sulfuric and nitric acids. These then mix with water and other materials before falling to the ground.</li>
</ul>
</li>
</ul>
<p><a href="https://www.downtoearth.org.in/news/natural-disasters/sulphur-dioxide-from-caribbean-volcano-reaches-india-wmo-confirms-76547#:~:text=The%20sulphur%20dioxide%20(SO2)%20emissions,can%20come%20down%20with%20rainfall." target="_blank" rel="noopener"><strong>Source: DTE</strong></a></p>',
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	(int) 14 => object(Cake\ORM\Entity) {

		'article_id' => (int) 8083,
		'category_id' => (int) 21,
		'title' => 'Effect of Dust on Monsoon',
		'description' => '<h3>Why in News</h3>
<p>Recently, a study details how the <strong>Indian monsoon</strong> gets influenced by the <strong>atmospheric dust particles</strong> swept up by winds <strong>from deserts in the Middle East (Asian Deserts).</strong></p>
<p><a href="http://www.drishtiias.com/images/uploads/1617625039_image4.jpg" target="_blank" rel="noopener"><strong><img class="content-img" src="http://www.drishtiias.com/images/uploads/1617625039_image4.jpg" style="display: block; margin-left: auto; margin-right: auto;" caption="false" width="576" height="250" /></strong></a></p>
<h3>Key Points</h3>
<ul style="list-style-type: square;">
<li><strong>Dust :</strong><br />
<ul style="list-style-type: circle;">
<li>Dust is <strong>very small dry particles of earth or sand.</strong><br />
<ul style="list-style-type: disc;">
<li><strong>PM10 and PM2.5</strong> refers to dust classified by the size of particles.</li>
</ul>
</li>
<li>The<strong> natural erosion of soil, sand and rock</strong> is the <strong>most common source</strong> of dust.</li>
<li>Dust emission is common in urban areas<strong> from a range of activities such as gardening, to large scale industrial operations.</strong></li>
<li>It is<strong> known to influence monsoons, hurricanes and even fertilize rainforests.</strong></li>
<li>The <strong>dust emission scheme is extremely sensitive to <a href="/daily-updates/daily-news-editorials/climate-change-and-development-in-india" target="_blank" rel="noopener">climate change</a></strong> and understanding these mechanisms and effects of dust can help understand our <a href="/to-the-points/paper1/monsoon-2" target="_blank" rel="noopener"><strong>monsoon</strong></a> systems in the face of global climate change.</li>
</ul>
</li>
<li><strong>Effect of Dust on Monsoon:</strong><br />
<ul style="list-style-type: circle;">
<li><strong>About:</strong><br />
<ul style="list-style-type: disc;">
<li>Dust storms from the desert when lifted by strong winds can absorb solar radiation and become hot.</li>
<li>This can cause <strong>heating of the atmosphere, change the air pressure, wind circulation patterns, influence moisture transport and increase precipitation and rainfall.</strong></li>
</ul>
</li>
<li><strong>Effect on Indian Monsoon:</strong><br />
<ul style="list-style-type: disc;">
<li>Dust from the <strong>Middle East [West Asia]</strong> and also from the <strong>Iranian Plateau</strong> also influences the <strong>Indian Summer Monsoon (<a href="/daily-updates/daily-news-analysis/indian-ocean-dipole-and-the-south-west-monsoon" target="_blank" rel="noopener">South West Monsoon</a>).</strong> <br />
<ul style="list-style-type: disc;">
<li>The hot air over the Iranian Plateau can heat the atmosphere over the plateau, strengthen the circulation over the deserts of the Arabian Peninsula and increase dust emission from the Middle East [West Asia].</li>
</ul>
</li>
</ul>
</li>
<li><strong>Reverse Effect:</strong><br />
<ul style="list-style-type: disc;">
<li>Indian Summer Monsoon has a reverse effect and can <strong>increase the winds in West Asia to produce yet more dust.</strong></li>
<li>A strong monsoon can also transport air to West Asia and again pick up a lot of dust.</li>
</ul>
</li>
</ul>
</li>
<li><strong>Effect of Anthropogenic Dust:</strong><br />
<ul style="list-style-type: circle;">
<li>There is <strong>a difference of opinion,</strong> some studies found that anthropogenic<a href="/daily-updates/daily-news-analysis/aerosol-levels-hit-20-year-low" target="_blank" rel="noopener"><strong> aerosols</strong></a> emitted from the Indian subcontinent can decrease summer monsoon precipitation, while others found that absorbing aerosols such as dust can strengthen the monsoon circulation. <br />
<ul style="list-style-type: disc;">
<li><strong>Aerosols</strong> are defined as a combination of liquid or solid particles suspended in a gaseous or liquid environment.</li>
<li><strong>Anthropogenic aerosols include sulfate, nitrate, and carbonaceous aerosols,</strong> and are mainly from fossil fuel combustion sources.</li>
</ul>
</li>
<li>However, a recent study showed that they can <strong>strengthen Indian summer monsoon rainfall.</strong><br />
<ul style="list-style-type: disc;">
<li>Aerosol particles, such as dust, play an important role in the precipitation process, providing the nuclei upon which condensation and freezing take place.</li>
</ul>
</li>
</ul>
</li>
<li><strong>Role of Deserts in Monsoon:</strong><br />
<ul style="list-style-type: circle;">
<li>Deserts across the globe play important roles in monsoons.<br />
<ul style="list-style-type: disc;">
<li>The dust aerosols from deserts in <strong>West China</strong> such as the <strong>Taklamakan desert</strong> and the<strong> Gobi Desert</strong> can be transported eastward to eastern China and can influence the East Asia summer monsoon.</li>
<li>In the <strong>southwest United States,</strong> there are some small deserts that influence the <strong>North African monsoon.</strong></li>
</ul>
</li>
</ul>
</li>
<li><strong>Major Deserts of the World:</strong></li>
</ul>
<p><a href="http://www.drishtiias.com/images/uploads/1617625297_image7.png" target="_blank" rel="noopener"><strong><img class="content-img" src="http://www.drishtiias.com/images/uploads/1617625297_image7.png" style="display: block; margin-left: auto; margin-right: auto;" width="700" caption="false" /></strong></a></p>
<h3>Monsoon</h3>
<ul style="list-style-type: square;">
<li><strong>About:</strong><br />
<ul style="list-style-type: circle;">
<li>A monsoon often brings about thoughts of torrential rains, similar to a hurricane or typhoon. But there is a difference: a <strong>monsoon is not a single storm; rather, it is a seasonal wind shift over a region.</strong></li>
<li>The shift may<strong> cause heavy rains in the summer,</strong> but at other times, it may cause a dry spell.</li>
</ul>
</li>
<li><strong>Cause for Monsoon:</strong><br />
<ul style="list-style-type: circle;">
<li>A monsoon <strong>(from the Arabic mawsim, which means "season")</strong> arises due to a <strong>difference in temperatures between a land mass and the adjacent ocean.</strong></li>
<li>The sun warms the land and ocean differently, causing the winds to play "tug of war" eventually <strong>switching directions bringing the cooler, moister air from over the ocean.</strong></li>
<li>The winds reverse again at the end of the monsoon season.</li>
</ul>
</li>
<li><strong>Types:</strong><br />
<ul style="list-style-type: circle;">
<li><strong>Wet Monsoon:</strong><br />
<ul style="list-style-type: disc;">
<li>A wet monsoon typically <strong>occurs during the summer months</strong> (about April through September) bringing heavy rains.</li>
<li>On average, approximately <strong>75% of India's annual rainfall</strong> and about <strong>50% of the North American monsoon region</strong> comes during the summer monsoon season.</li>
<li>The wet monsoon begins when winds bring cooler, more humid air from above the oceans to the land.</li>
</ul>
</li>
<li><strong>Dry Monsoon:</strong><br />
<ul style="list-style-type: disc;">
<li>A dry monsoon typically occurs between<strong> October and April.</strong></li>
<li>Instead of coming from the oceans, the <strong>winds tend to come from drier, warmer climates</strong> such as from Mongolia and northwestern China down into India.</li>
<li>Dry monsoons tend to be<strong> less powerful than their summer counterparts.</strong></li>
<li>The winter monsoon occurs when "the land cools off faster than the water and a high pressure develops over the land, blocking any ocean air from penetrating." This leads to a dry period.</li>
</ul>
</li>
</ul>
</li>
<li><strong>Location:</strong><br />
<ul style="list-style-type: circle;">
<li>A monsoon forms in the tropics <strong>(between 0 and 23.5 degrees latitude north and south)</strong> and subtropics <strong>(between 23.5 degrees and 35 degrees latitude north and south).</strong></li>
<li>The <strong>strongest monsoons tend to occur in India and South Asia in the north and Australia and Malaysia in the south.</strong></li>
<li>Monsoons also occur in southern parts of North America, in Central America, northern areas of South America, and in western Africa.</li>
</ul>
</li>
</ul>
<p><a href="https://www.thehindu.com/sci-tech/science/how-asian-desert-dust-enhances-indian-summer-monsoon/article34232324.ece" target="_blank" rel="noopener"><strong>Source:TH</strong></a></p>',
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	(int) 15 => object(Cake\ORM\Entity) {

		'article_id' => (int) 7922,
		'category_id' => (int) 21,
		'title' => 'Sangay Volcano: Ecuador',
		'description' => '<h3>Why in News</h3>
<p>Recently, Ecuador&rsquo;s <strong>Sangay <a href="/daily-updates/daily-news-analysis/eruption-on-mount-etna" target="_blank" rel="noopener">volcano</a></strong> erupted.</p>
<h3>Key Points</h3>
<ul style="list-style-type: square;">
<li><strong>About Sangay Volcano:<a href="http://www.drishtiias.com/images/uploads/1615619648_image2.jpg" target="_blank" rel="noopener"><img class="content-img" src="http://www.drishtiias.com/images/uploads/1615619648_image2.jpg" style="float: right;" width="300" caption="false" /></a></strong><br />
<ul style="list-style-type: circle;">
<li>Sangay volcano is one of the <strong>highest active volcanoes in the world</strong> and one of <strong>Ecuador's most active ones.</strong></li>
<li>Sangay is the southernmost <strong>stratovolcano</strong> (a volcano built up of <strong>alternate layers of lava and ash</strong>) in the northern volcanic zone of the Andes. It is 5230 m high.<br />
<ul style="list-style-type: disc;">
<li>The Andes is the <strong>longest above water mountain range in the world</strong> and boasts some of the highest peaks.</li>
<li><strong>Sangay National Park</strong> is located in the central part of Ecuador on the Andes mountains' eastern side. It is a <a href="/to-the-points/paper1/world-heritage-sites-in-india" target="_blank" rel="noopener"><strong>world heritage site</strong></a>.</li>
</ul>
</li>
</ul>
</li>
<li><strong>Eruptions:</strong><br />
<ul style="list-style-type: circle;">
<li>The <strong>earliest</strong> report of a historical eruption was in <strong>1628</strong>. More or less continuous eruptions were reported from 1728 until 1916, and again from 1934 to the present. Sangay <strong>has had frequent eruptions in historic times</strong>, mostly of <strong>strombolian type.</strong></li>
</ul>
</li>
<li><strong>Other Major Volcanoes of Ecuador:</strong> <br />
<ul style="list-style-type: circle;">
<li>Ecuador, part of the <a href="/to-the-points/paper1/pacific-ring-of-fire" target="_blank" rel="noopener"><strong>Pacific Rim&rsquo;s &ldquo;Ring of Fire&rdquo;</strong></a> region, has eight volcanoes such as <strong>Cotopaxi</strong> (5,897m), <strong>Cayambe</strong> (5,790m), <strong>Pichincha</strong> (4,784m) etc. in its territory.</li>
</ul>
</li>
</ul>
<div class="border-bg">
<p><strong>Volcanic Eruptions</strong></p>
<ul style="list-style-type: square;">
<li><strong>About:</strong><br />
<ul style="list-style-type: circle;">
<li>Volcanic eruptions happen when <strong>lava and gas are discharged from a volcanic vent.</strong></li>
<li>The most common consequences of this are population movements as large numbers of people are often forced to flee the moving lava flow.</li>
</ul>
</li>
<li><strong>Types:</strong> Volcanic activity and volcanic areas are commonly divided into <strong>six major types:</strong><br />
<ul style="list-style-type: circle;">
<li><strong>Icelandic:</strong> <br />
<ul style="list-style-type: disc;">
<li>It is characterized by <strong>effusions of molten basaltic lava</strong> that flow from long, parallel fissures. Such outpourings <strong>often build lava plateaus.</strong></li>
</ul>
</li>
<li><strong>Hawaiian:</strong> <br />
<ul style="list-style-type: disc;">
<li>It is <strong>similar to the Icelandic variety.</strong> In this case, however, fluid lava flows from a volcano&rsquo;s summit and <strong>radial fissures</strong> to form shield volcanoes, which are quite large and <strong>have gentle slopes.</strong></li>
</ul>
</li>
<li><strong>Strombolian:</strong> <br />
<ul style="list-style-type: disc;">
<li>These involve <strong>moderate bursts of expanding gases</strong> that eject clots of incandescent lava in cyclical or nearly <strong>continuous small eruptions.</strong></li>
<li>Because of such small frequent outbursts, <strong>Stromboli volcano</strong>, located on Stromboli Island off the northeast coast of <strong>Italy</strong>, has been called the <strong>&ldquo;lighthouse of the Mediterranean.&rdquo;</strong></li>
</ul>
</li>
<li><strong>Vulcanian:</strong> <br />
<ul style="list-style-type: disc;">
<li>It is named for <strong>Vulcano Island</strong> near Stromboli, generally involving <strong>moderate explosions</strong> <strong>of gas laden with volcanic ash.</strong> This mixture forms dark, turbulent eruption clouds that rapidly ascend and expand in convoluted shapes.</li>
</ul>
</li>
<li><strong>Pelean:</strong> <br />
<ul style="list-style-type: disc;">
<li>It is associated with explosive outbursts that generate <strong>pyroclastic flows</strong>, dense mixtures of <strong>hot volcanic fragments and gas.</strong></li>
<li>The <strong>fluidized slurries</strong> produced by these eruptions are heavier than air but are of low viscosity and pour down valleys and slopes at great velocities. As a result, they are <strong>extremely destructive.</strong></li>
</ul>
</li>
<li><strong>Plinian:</strong> <br />
<ul style="list-style-type: disc;">
<li>This type is an <strong>intensely violent kind of volcanic eruption.</strong> In this type of eruption, gases boiling out of gas-rich magma generate enormous and nearly continuous jetting blasts that core out the magma conduit and rip it apart.</li>
<li>The uprushing gases and volcanic fragments <strong>resemble a gigantic</strong> <strong>rocket blast directed vertically upward.</strong> Plinian <strong>eruption clouds can rise into the stratosphere</strong> and are sometimes continuously produced for several hours.</li>
<li><strong>Lightning strikes</strong> caused by a buildup of static electricity are common close to Plinian ash clouds, adding one more element of terror to the eruption.</li>
</ul>
</li>
</ul>
</li>
</ul>
<p><a href="http://www.drishtiias.com/images/uploads/1615620904_image3.jpg" target="_blank" rel="noopener"><img class="content-img" src="http://www.drishtiias.com/images/uploads/1615620904_image3.jpg" width="750" caption="false" style="display: block; margin-left: auto; margin-right: auto;" /></a></p>
</div>
<p><a href="https://indianexpress.com/article/world/ecuadors-sangay-volcano-erupts-ash-8-kilometers-7225406/" target="_blank" rel="noopener"><strong>Source:IE</strong></a></p>',
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	(int) 16 => object(Cake\ORM\Entity) {

		'article_id' => (int) 7745,
		'category_id' => (int) 21,
		'title' => 'Declining Rainfall in Cherrapunji',
		'description' => '<h3>Why in News</h3>
<p>A recent study that looked at the <strong>rainfall pattern in the past 119 years</strong> found a <strong>decreasing trend at Cherrapunji (Meghalaya) and nearby areas.</strong></p>
<ul style="list-style-type: square;">
<li>The village of <strong>Mawsynram in East Khasi Hills district of Meghalaya</strong> has beaten Cherrapunji to become the <strong>wettest place in the world.</strong> Mawsynram receives over 10,000 millimetres of rain in a year.</li>
<li>Mawsynram is located around <strong>81 km by road from Cherrapunji</strong> however the straight line distance between the two is <strong>15.2 km.</strong></li>
</ul>
<p><a href="http://www.drishtiias.com/images/uploads/1613980587_image1.png" target="_blank" rel="noopener"><strong><img class="content-img" src="http://www.drishtiias.com/images/uploads/1613980587_image1.png" style="display: block; margin-left: auto; margin-right: auto;" width="400" caption="false" /></strong></a></p>
<h3>Key Points</h3>
<ul style="list-style-type: square;">
<li><strong>Reduction in Rainfall:</strong>
<ul style="list-style-type: circle;">
<li>The <strong>annual mean rainfall</strong> for the period <strong>1973&ndash;2019</strong> showed <strong>decreasing trends</strong> of about <strong>0.42 mm per decade.</strong>
<ul style="list-style-type: disc;">
<li>It was statistically significant along seven stations <strong>(Agartala, Cherrapunji, Guwahati, Kailashahar, Pasighat, Shillong and Silchar).</strong></li>
</ul>
</li>
</ul>
</li>
<li><strong>Reasons:</strong><br />
<ul style="list-style-type: circle;">
<li><strong>Rising Temperature:</strong><br />
<ul style="list-style-type: disc;">
<li>The <strong>changes in the Indian Ocean temperature</strong> have a <strong>huge effect</strong> on the rainfall in the region.<br />
<ul style="list-style-type: disc;">
<li>Increasing sea surface temperatures in the tropical Indian Ocean region was pointed out by the <a href="/daily-updates/daily-news-analysis/assessment-of-climate-change-over-the-indian-region-moes" target="_blank" rel="noopener"><strong>first climate change assessment report</strong></a> published by the Union Ministry of Earth Sciences in June 2020.</li>
</ul>
</li>
</ul>
</li>
<li><strong>Increased Human Activities:</strong><br />
<ul style="list-style-type: disc;">
<li>The satellite data showed that there was a <strong>reduction in the vegetation area</strong> in northeast India in the past two decades, implying that human influence also plays an important role in the changing rainfall patterns.<br />
<ul style="list-style-type: disc;">
<li>The traditional way of cultivation known as <a href="/daily-updates/daily-news-analysis/niti-aayog-report-on-shifting-cultivation" target="_blank" rel="noopener"><strong>Jhum cultivation or shifting cultivation</strong></a> is now decreased and being replaced by other methods.</li>
<li>There is sizable <a href="/daily-updates/daily-news-analysis/deforestation-rate-declined"><strong>deforestation</strong></a> in the region. The study saw the <strong>decrease in vegetation cover and increase in the areas of cropland</strong> mainly from the year 2006 onwards.</li>
<li>The analysis showed <strong>reductions in vegetation</strong> with <strong>104.5 sqkm lost per year.</strong></li>
<li>On the other hand, there were <strong>significant increases in cropland</strong> (182.1 sqkm per year) and <strong>urban and built-up lands</strong> (0.3 sqkm per year) during the period 2001&ndash;2018.</li>
</ul>
</li>
</ul>
</li>
</ul>
</li>
<li><strong>Significance of Studying the North-East Region:</strong><br />
<ul style="list-style-type: circle;">
<li>Since north-east India is mostly hilly and is an extension of the Indo-Gangetic Plains, the <strong>region is highly sensitive to changes</strong> in regional and global climate.</li>
<li>It has to be noted that the <strong>first signs of the effect of <a href="/daily-updates/daily-news-editorials/climate-change-and-development-in-india" target="_blank" rel="noopener">climate change</a></strong> will be evident for the extreme cases such as the rainfall at Cherrapunji.</li>
<li>North-east India has the <strong>highest vegetation cover</strong> in India and includes <strong>18 biodiversity hotspots of the world</strong>, indicating the importance of the region in terms of its greenery and <strong>climate-change sensitivity.</strong></li>
</ul>
</li>
</ul>
<div class="border-bg">
<p><strong>Reason for High Rainfall in Cherrapunji and Mawsynram</strong></p>
<ul style="list-style-type: square;">
<li><strong>Cherrapunji (elevation 1313 m)</strong> and <strong>Mawsynram (elevation 1401.5 m)</strong> are located on the southern slopes of the east Khasi Hills in Meghalaya. <br />
<ul style="list-style-type: circle;">
<li>Meghalaya is a mountainous state with <strong>numerous valleys and highland plateaus.</strong></li>
<li><strong>Elevation</strong> in the plateau region ranges between <strong>150 m</strong> to <strong>1,961 m ,</strong> with the central part comprising the Khasi Hills with the highest elevations.</li>
</ul>
</li>
<li>The rainfall in Cherrapunji-Mawsynram is <strong>caused by the orography favouring a monsoon wind regime.</strong></li>
<li>The northward moving moist winds from the Bay of Bengal passing over the plains of Bangladesh are <strong>forced to converge in the narrow valleys of the Khasi Hills</strong> with orography providing forced ascent that causes condensation, formation of clouds resulting in rain on the windward side of the slope.</li>
</ul>
<p><strong>Shifting Cultivation</strong></p>
<ul style="list-style-type: square;">
<li>Shifting cultivation, locally called 'Jhum', is a widely practiced system of crop cultivation among the indigenous communities of North-east India. The practice, also known as <strong>slash-and-burn agriculture</strong>, is when farmers clear land by slashing vegetation and burning forests and woodlands to create clear land for agricultural purposes.</li>
<li>This provides a <strong>very easy and very fast method</strong> of the preparation of the land for agriculture.</li>
<li>The bush and the weeds can be removed easily. The <strong>burning of waste materials provides needed nutrients for the cultivation.</strong></li>
<li>It <strong>gives</strong> a family its <strong>food, fodder, fuel, livelihood</strong> and is closely linked to their identity.</li>
<li>Because of cutting of forests and trees, this practice <strong>leads to soil erosion and may also affect the course of rivers.</strong></li>
</ul>
</div>
<p><a href="https://www.thehindu.com/sci-tech/science/wettest-place-on-earth-sees-decreasing-trend-in-rainfall/article33889697.ece#:~:text=The%20quiet%2C%20sleepy%2C%20yet%20mesmerising,to%20The%20Hindu%20subscribers%20only." target="_blank" rel="noopener"><strong>Source:TH</strong></a></p>',
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		'article_id' => (int) 7743,
		'category_id' => (int) 26,
		'title' => 'Deglaciation and Threats',
		'description' => '<h3>Deglaciation </h3>
<ul style="list-style-type: square;">
<li>Glaciers, ice caps and continental ice sheets <strong>cover some 10% of the earth&rsquo;s land surface</strong> at the present time, whereas during the ice ages, they covered about three times this amount <br />
<ul style="list-style-type: circle;">
<li>The present ice cover corresponds to about three-quarter of the world&rsquo;s total freshwater resources. </li>
</ul>
</li>
<li>The gradual melting away of a glacier from the surface of a landmass is known as <strong>Deglaciation.</strong><br />
<ul style="list-style-type: circle;">
<li>The processes that remove snow, ice, and moraine from a glacier or ice sheet are called <strong>Ablation.</strong> <br />
<ul style="list-style-type: disc;">
<li>It includes melting, evaporation, erosion, and calving.</li>
</ul>
</li>
</ul>
</li>
<li>The process of deglaciation, that intensified in the 20th century, is leaving our planet iceless. </li>
</ul>
<h3>Causes of Deglaciation</h3>
<ul style="list-style-type: square;">
<li><strong>Global warming:</strong> The atmospheric concentration of carbon dioxide, methane and other greenhouse gases (GHGs) produced by <strong>industry, transport, deforestation and burning fossil fuels,</strong> amongst other human activities, <strong>warm the planet and cause glaciers to melt.</strong></li>
<li><strong>Ocean warming:</strong> Oceans absorb 90% of the Earth's warmth, and this affects the melting of marine glaciers, which are mostly located near the poles.</li>
<li><strong>Rapid industrialisation:</strong> Since the early 1900s, many glaciers around the world have been rapidly melting, <strong>specifically, since the industrial revolution,</strong> carbon dioxide and other<strong> greenhouse gas emissions have raised temperatures,</strong> even <strong>higher in the poles,</strong> and as a result, glaciers are rapidly melting, calving off into the sea and retreating on land.</li>
</ul>
<h3>Impacts of Deglaciation</h3>
<ul style="list-style-type: square;">
<li><strong>Raised sea level:</strong> The melting glaciers have played the major role in<strong> raising average global sea level between four and eight inches</strong> (10 and 20 centimeters) in the past hundred years, according to the <a href="/daily-updates/daily-news-analysis/special-report-on-climate-change-ipcc" target="_blank" rel="noopener"><strong>Intergovernmental Panel on Climate Change (IPCC).</strong></a><br />
<ul style="list-style-type: circle;">
<li>Rising sea levels increase coastal erosion and elevates storm surge as warming air and ocean temperatures create more frequent and intense coastal storms like hurricanes and typhoons.</li>
</ul>
</li>
<li><strong>On mountain glaciers:</strong> The famed snows of <strong>Kilimanjaro</strong> have melted more than 80% since 1912. <br />
<ul style="list-style-type: circle;">
<li><strong>Glaciers in the Garhwal region</strong> of the Himalayas are retreating so fast that researchers believe that most central and eastern Himalayan glaciers could virtually disappear by 2035. </li>
</ul>
</li>
<li><strong>In the Northern Hemisphere:</strong> Spring freshwater ice breakup in the Northern Hemisphere now<strong> occurs nine days earlier</strong> than it did 150 years ago, and <strong>autumn freeze-up ten days later. </strong><br />
<ul style="list-style-type: circle;">
<li><strong>Arctic sea</strong> ice has thinned significantly over the past half century, and its extent has declined by about 10% in the past 30 years. </li>
<li>The <strong>Greenland</strong> ice sheet is disappearing four times faster than in 2003 and already contributes 20% of current sea level rise.</li>
</ul>
</li>
<li><strong>Melting of Thwaites Glacier:</strong> Also called <a href="/daily-updates/daily-news-analysis/melting-of-thwaites-glacier" target="_blank" rel="noopener"><strong>Doomsday Glacier</strong></a>, it is a 120 km wide, fast-moving glacier located in <strong>Antarctica.</strong><br />
<ul style="list-style-type: circle;">
<li>Because of its size (1.9 lakh square km), it contains enough water to raise the world sea level by more than half a metre.</li>
<li>Studies have detected the <strong>presence of warm water</strong> at a vital point beneath the Thwaites glacier as the cause of its melting.</li>
<li>Its <strong>melting already contributes 4% to global sea-level rise each year.</strong> It is estimated that it would collapse into the sea in 200-900 years.<br />
<ul style="list-style-type: disc;">
<li>Studies have found the amount of ice flowing out of it has nearly doubled over the past 30 years.</li>
</ul>
</li>
</ul>
</li>
<li><strong>Disappearance of species:</strong> Glaciers are the natural habitat of a number of animals, both terrestrial and aquatic, if the melting continues at the same rate, a number of species will become extinct.<br />
<ul style="list-style-type: circle;">
<li>It will also disturb the balance of the food chain.</li>
</ul>
</li>
</ul>
<p><a href="http://www.drishtiias.com/images/uploads/1613974001_image1.jpg" target="_blank" rel="noopener"><img class="content-img" src="http://www.drishtiias.com/images/uploads/1613974001_image1.jpg" style="display: block; margin-left: auto; margin-right: auto;" width="550" caption="false" /></a></p>
<h3>The Himalayan Glaciers</h3>
<p><strong>About</strong></p>
<ul style="list-style-type: square;">
<li>Himalayan glaciers form the largest body of ice outside the polar caps and are the source of water for the innumerable rivers that flow across the Indo-Gangetic plains. <br />
<ul style="list-style-type: circle;">
<li>Himalayan glaciers are also known as the Third Pole. </li>
</ul>
</li>
<li>Himalayan glacial snowfields store about 12,000 km3 of freshwater. </li>
<li>15,000 Himalayan glaciers form a unique reservoir which supports perennial rivers such as the Indus, Ganga and Brahmaputra which, in turn, are the lifeline of millions of people in South Asian countries (Pakistan, Nepal, Bhutan, India and Bangladesh). </li>
<li>The Gangetic basin alone is home to 500 million people, about 10% of the total human population in the region.</li>
</ul>
<p><strong>The Receding Glaciers</strong></p>
<ul style="list-style-type: square;">
<li><strong>Rate of receding:</strong> Glaciers in the Himalaya are receding faster than in any other part of the world. <br />
<ul style="list-style-type: circle;">
<li>The glaciers have been losing the equivalent of more than a vertical foot and half of ice each year since 2000; double the amount of melting that took place from 1975 to 2000.</li>
<li>According to the statistics in the last 25 years approximate 400 crore tons of ice being melted in the Himalayan glaciers.</li>
<li>The 30.2 km long <a href="/daily-updates/daily-news-analysis/concentration-of-black-carbon-on-gangotri-glacier" target="_blank" rel="noopener"><strong>Gangotri Glacier</strong> </a>has been receding alarmingly in recent years.</li>
</ul>
</li>
<li><strong>Cause of receding:</strong> The receding and thinning of Himalayan glaciers can be attributed primarily to global warming due to increase in anthropogenic emission of greenhouse gases. <br />
<ul style="list-style-type: circle;">
<li>The relatively high population density near these glaciers and consequent deforestation and land-use changes have also adversely affected these glaciers. </li>
</ul>
</li>
<li><strong>Effect on the Hindukush region:</strong> Climate change has hastened glacial melting across the <a href="/daily-updates/daily-news-analysis/hindu-kush-himalayan-region" target="_blank" rel="noopener"><strong>Hindu Kush Himalayan (HKH) region</strong></a>, home to some of the world&rsquo;s tallest peaks, including Mount Everest.<br />
<ul style="list-style-type: circle;">
<li>The recent <a href="/daily-updates/daily-news-analysis/uttarakhand-flash-flood" target="_blank" rel="noopener"><strong>glacier collapse at Nanda Devi</strong></a> in Uttarakhand&rsquo;s Chamoli district led to a massive flood in the Dhauli Ganga river and caused large-scale devastation in the upper reaches of the ecologically fragile Himalayas.</li>
</ul>
</li>
<li><strong>Air warming over HKH:</strong> Air over HKH warmed at a rate of 0.2℃ each decade from 1951 to 2014 and at an even higher rate of 0.5℃ per decade at elevations higher than 4,000 meters, as per a report prepared by the Ministry of Earth Sciences (MoES). <br />
<ul style="list-style-type: circle;">
<li>The report projected that even with the Indian government&rsquo;s commitment to mitigate greenhouse gases by 2030, the Indian Himalayas could warm by 2.6℃&ndash;4.6℃ by 2100. </li>
<li>In the worst-case scenario, the mean surface temperature over the whole region could rise by 5.2℃ by 2100.</li>
</ul>
</li>
</ul>
<p><a href="http://www.drishtiias.com/images/uploads/1613973937_image2.png" target="_blank" rel="noopener"><img class="content-img" src="http://www.drishtiias.com/images/uploads/1613973937_image2.png" style="display: block; margin-left: auto; margin-right: auto;" width="500" caption="false" /></a></p>',
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	(int) 18 => object(Cake\ORM\Entity) {

		'article_id' => (int) 7688,
		'category_id' => (int) 26,
		'title' => 'Glaciers',
		'description' => '<h3>About</h3>
<ul style="list-style-type: square;">
<li>A glacier is a large, <strong>perennial accumulation of crystalline ice, snow, rock, sediment,</strong> and <strong>water</strong> that originates on land and moves down slope under the influence of its own weight and gravity. They are <strong>sensitive indicators of changing climate.</strong></li>
<li>Out of total water on Earth, <strong>2.1% is in glaciers while 97.2% is in the oceans</strong> and inland seas.</li>
<li><strong>Condition of glacier formation:</strong><br />
<ul style="list-style-type: circle;">
<li><strong>Mean annual temperatures</strong> are close to the freezing point.</li>
<li><strong>Winter precipitation</strong> produces significant accumulations of snow.</li>
<li><strong>Temperatures throughout the rest of the year</strong> do not result in the complete loss of the previous winter&rsquo;s snow accumulation.</li>
</ul>
</li>
</ul>
<p><strong>Formation of Glacier</strong></p>
<ul style="list-style-type: square;">
<li>Glaciers begin forming in places where more snow piles up each year than melts. Soon after falling, the snow begins to compress, or become denser and tightly packed.<br />
<ul style="list-style-type: circle;">
<li>The process of snow compacting into glacial firn (dense, grainy ice) is called <strong>firnification</strong>.</li>
</ul>
</li>
<li>When the ice grows thick enough, about 50 meters (160 feet), the firn grains fuse into a huge mass of solid ice. The glacier begins to move under its own weight.<br />
<ul style="list-style-type: circle;">
<li>Different parts of a glacier move at different speeds. The flowing ice in the middle of the glacier moves faster than the base.</li>
</ul>
</li>
</ul>
<p><strong>Geographical Location</strong></p>
<ul style="list-style-type: square;">
<li><strong>91%</strong> of the Glaciers are in <strong>Antarctica</strong> and <strong>8%</strong> are in <strong>Greenland.</strong> They occupy about 10% of the world's total land area.</li>
</ul>
<p><a href="http://www.drishtiias.com/images/uploads/1613373504_image1.png" target="_blank" rel="noopener"><img class="content-img" src="http://www.drishtiias.com/images/uploads/1613373504_image1.png" width="600" caption="false" style="display: block; margin-left: auto; margin-right: auto;" /></a></p>
<p><strong>Significance:</strong></p>
<ul style="list-style-type: square;">
<li><strong>Glaciers as Reservoirs:</strong> About <strong>three-quarters</strong> of Earth's freshwater is stored in glaciers. Therefore, glacier ice is the <strong>second largest reservoir of water</strong> on Earth and the <strong>largest reservoir of freshwater</strong> on Earth.<br />
<ul style="list-style-type: circle;">
<li>The cold runoff from glaciers also affects downstream water temperatures.</li>
</ul>
</li>
<li><strong>Glaciers feeding Rivers:</strong> The <strong>Gangotri Glacier</strong>, one of the largest glaciers in the Himalayan Mountains, is <strong>the source of the Ganga River</strong>. <br />
<ul style="list-style-type: circle;">
<li>The Ganges is the most important source of freshwater and electricity in India and Bangladesh.</li>
</ul>
</li>
<li><strong>Glaciers for Aquatic Life:</strong> Many <strong>aquatic species in mountainous environments</strong> require cold water temperatures to survive which is provided by Glaciers. <br />
<ul style="list-style-type: circle;">
<li>Some <strong>aquatic insects</strong> are <strong>especially sensitive to stream temperature</strong> and cannot survive without the cooling effects of glacial meltwater.</li>
<li>Such changes in stream habitat may also <strong>adversely impact native trout</strong> and other <strong>keystone salmon species.</strong></li>
</ul>
</li>
<li><strong>Glaciers for People:</strong> Glaciers provide people with many useful resources. Glacial till <strong>provides fertile soil for growing crops</strong>.<br />
<ul style="list-style-type: circle;">
<li>Deposits of sand and gravel are used to make <strong>concrete and asphalt</strong>.</li>
</ul>
</li>
</ul>
<h3>Classification of Glaciers</h3>
<ul style="list-style-type: square;">
<li>Glaciers can be classified according to their: <br />
<ul style="list-style-type: circle;">
<li><strong>Size</strong> (i.e. ice sheet, ice cap, valley glacier, cirque glacier)</li>
<li><strong>Thermal regime</strong> (polar vs. temperate).</li>
</ul>
</li>
</ul>
<p><strong>Size Based</strong></p>
<ul style="list-style-type: square;">
<li><strong>Ice Cap:</strong> An ice cap is a dome-shaped glacier mass flowing in all directions, such as the ice cap on Ellesmere Island in the Canadian Arctic. <br />
<ul style="list-style-type: circle;">
<li>There is still some <strong>uncertainty about the full volume of glaciers and ice caps</strong> on Earth, but if all of them were to melt, <strong>global sea level would rise approximately 70 meters</strong> (approximately 230 feet), flooding every coastal city on the planet.</li>
</ul>
</li>
<li><strong>Valley Glaciers:</strong> Also called <strong>Alpine Glaciers</strong> or <strong>Mountain Glaciers</strong>, they form on mountainsides and move downward through valleys. <br />
<ul style="list-style-type: circle;">
<li>They are <strong>found in high mountains</strong> <strong>of every continent except Australia</strong> (although there are many in New Zealand). <br />
<ul style="list-style-type: disc;">
<li>Example: The <strong>Gorner Glacier in Switzerland</strong> and the <strong>Furtwangler Glacier in Tanzania</strong>.</li>
</ul>
</li>
</ul>
</li>
<li><strong>Ice Sheets:</strong> Unlike valley glaciers, ice sheets are not limited to mountainous areas. They form broad domes and spread out from their centers in all directions. <br />
<ul style="list-style-type: circle;">
<li>As ice sheets spread, they cover everything around them with a thick blanket of ice, including valleys, plains, and even entire mountains.</li>
<li>The largest ice sheets, called <strong>continental glaciers</strong>, spread over vast areas. <br />
<ul style="list-style-type: disc;">
<li>Continental glaciers <strong>cover most of Antarctica and the island of Greenland</strong>.</li>
</ul>
</li>
</ul>
</li>
<li><strong>Cirque glaciers:</strong> They are short and wide, are confined to cirques, or amphitheatres, cut in the mountain landscape.</li>
</ul>
<p><strong>Thermal Regime based:</strong></p>
<ul style="list-style-type: square;">
<li><strong>Polar Glacier:</strong> A polar glacier is defined as one that is below the freezing temperature throughout its mass for the entire year.<br />
<ul style="list-style-type: circle;">
<li>A subpolar glacier contains ice below the freezing temperature, except for surface melting in the summer and a basal layer of temperate ice.</li>
</ul>
</li>
<li><strong>Temperate Glacier:</strong> A temperate glacier is the one that&rsquo;s <strong>essentially at the melting point</strong>, so liquid water coexists with glacier ice. <br />
<ul style="list-style-type: circle;">
<li>They are found in North America, South America, Europe, Africa, and <strong>Asia</strong> and <strong>New Zealand.</strong> <br />
<ul style="list-style-type: disc;">
<li>Some of the <strong>Antarctic glaciers</strong> and <strong>Greenland&rsquo;s southern outlet glaciers</strong> are temperate.</li>
</ul>
</li>
</ul>
</li>
</ul>
<h3>Landforms Formed</h3>
<p><strong>Erosional Landforms</strong><br /><strong></strong></p>
<ul style="list-style-type: square;">
<li><strong>Glacial Valleys/Troughs:</strong> These valleys are <strong>trough-like and U-shaped</strong> with broad floors and relatively smooth, and steep sides. <br />
<ul style="list-style-type: circle;">
<li>The valleys may contain littered debris or debris shaped as <strong>moraines</strong> with swampy appearance.</li>
<li>Very deep glacial troughs filled with sea water and making up shorelines (in high latitudes) are called <strong>fjords/fiords.</strong></li>
</ul>
</li>
<li><strong>Cirques:</strong> Often are found at the heads of glacial valleys, these are the most common of landforms in glaciated mountains. <br />
<ul style="list-style-type: circle;">
<li>They are <strong>deep, long and wide troughs</strong> or basins with very steep concave to vertically dropping high walls at its head as well as sides.</li>
<li>A lake of water can be seen quite often within the cirques after the glacier disappears. Such lakes are called <strong>cirque lakes or tarn lakes.</strong></li>
</ul>
</li>
<li><strong>Horns and Serrated:</strong> Ridges Horns form through headward erosion of the cirque walls. <br />
<ul style="list-style-type: circle;">
<li>If three or more radiating glaciers cut headward until their cirques meet, high, sharp pointed and steep sided peaks called horns form.</li>
</ul>
</li>
</ul>
<p><strong>Depositional Landforms:</strong></p>
<ul style="list-style-type: square;">
<li><strong>Glacial Till:</strong> The unassorted coarse and fine debris dropped by the melting glaciers is called glacial till. <br />
<ul style="list-style-type: circle;">
<li>Some amount of rock debris small enough to be carried by such melt-water streams is washed down and deposited. <br />
<ul style="list-style-type: disc;">
<li>Such glaciofluvial deposits are called <strong>outwash deposits</strong>.</li>
<li>The outwash deposits are roughly stratified and assorted.</li>
</ul>
</li>
</ul>
</li>
<li><strong>Moraines:</strong> They are <strong>long ridges of deposits of glacial till.</strong> <br />
<ul style="list-style-type: circle;">
<li><strong>Terminal moraines</strong> are long ridges of debris deposited at the end (toe) of the glaciers.</li>
<li>Lateral moraines form along the sides parallel to the glacial valleys.</li>
<li>Many valley glaciers retreating rapidly leave an irregular sheet of till over their valley floors called <strong>ground moraines.</strong></li>
<li>The moraine in the centre of the glacial valley flanked by lateral moraines is called <strong>medial moraine.</strong> <br />
<ul style="list-style-type: disc;">
<li>They are imperfectly formed as compared to lateral moraines. Sometimes medial moraines are indistinguishable from ground moraines.</li>
</ul>
</li>
</ul>
</li>
<li><strong>Eskers:</strong> These are ridges made of sands and gravels, deposited by glacial meltwater flowing through tunnels within and underneath glaciers, or through meltwater channels on top of glaciers.<br />
<ul style="list-style-type: circle;">
<li>Over time, the channel or tunnel gets filled up with sediments. As the ice retreats, the sediments are left behind as a ridge in the landscape.</li>
</ul>
</li>
<li><strong>Drumlins:</strong> They are <strong>smooth oval shaped ridge-like features</strong> composed mainly of glacial till with some masses of gravel and sand. <br />
<ul style="list-style-type: circle;">
<li>The long axes of drumlins are parallel to the direction of ice movement.</li>
<li>They may measure up to 1 km in length and 30 m or so in height.</li>
<li>The drumlin end facing the glacier is called the stoss end and is blunter and steeper than the other end called tail.&nbsp;</li>
</ul>
</li>
</ul>
<p><a href="http://www.drishtiias.com/images/uploads/1613374293_Image1.PNG" target="_blank" rel="noopener"><img class="content-img" src="http://www.drishtiias.com/images/uploads/1613374293_Image1.PNG" style="display: block; margin-left: auto; margin-right: auto;" width="600" caption="false" /></a></p>',
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	(int) 19 => object(Cake\ORM\Entity) {

		'article_id' => (int) 7649,
		'category_id' => (int) 21,
		'title' => 'Mapping Seismic Hazard of Eastern Himalaya',
		'description' => '<h3>Why in News</h3>
<p>Recently, scientists have found the <strong>first geological evidence of an earthquake on the border of Assam and Arunachal Pradesh,</strong> documented as the <strong>Sadiya earthquake in history.</strong> This finding could contribute to a seismic hazard map of the eastern Himalaya, which can facilitate construction and planning in the region.</p>
<ul style="list-style-type: square;">
<li>This site is near the <strong>Tuting-Tidding Suture Zone-</strong> a major part of the Eastern Himalaya, where the Himalaya takes a sharp southward bend and connects with the Indo-Burma Range.</li>
</ul>
<h3>Key Points</h3>
<ul style="list-style-type: square;">
<li><strong>About:</strong> <br />
<ul style="list-style-type: circle;">
<li>Scientists from <strong>Wadia Institute of <a href="/daily-updates/daily-news-analysis/tectonically-active-zone-of-himalayas" target="_blank" rel="noopener">Himalayan Geology</a> (WIHG)</strong> carried out a mega trench excavation at <strong>Himebasti village, Arunachal Pradesh</strong> where the most recent event records the imprints of the<strong> 1697 Sadiya earthquake</strong> and analysed it with modern geological techniques.<br />
<ul style="list-style-type: disc;">
<li>WIHG is an<strong> autonomous institute</strong> under the Department of Science and Technology (DST), Government of India.</li>
</ul>
</li>
<li>Scientists found large tree trunks embedded in the<strong> youngest flood deposits at the exit of the Subansiri River</strong> (Sadiya town is located roughly 145 km southeast of Subansiri river), suggesting the <strong>post-seismic aggradation of the river</strong> following an array of<strong> aftershocks</strong> till six months.<br />
<ul style="list-style-type: disc;">
<li><strong>Aggradation</strong> is the term used in geology for the increase in land elevation due to deposition of sediment.</li>
<li><strong>Aftershocks</strong> are earthquakes that follow the largest shock of an earthquake sequence. They are smaller than the mainshock and within 1-2 rupture lengths distance from the mainshock.</li>
</ul>
</li>
</ul>
</li>
<li><strong>Significance:</strong> <br />
<ul style="list-style-type: circle;">
<li>Studying the past earthquakes help to <strong>determine the seismic potential</strong> of the region. This helps in mapping the earthquake hazard of the region and enables syncing the development activities accordingly.</li>
<li>Arunachal Pradesh, being near the <a href="/daily-updates/daily-news-analysis/india-china-conflict" target="_blank" rel="noopener"><strong>Indo-China Border</strong></a>, and sometimes centre of dispute regarding its ownership, is strategically important. <br />
<ul style="list-style-type: disc;">
<li>A number of development initiatives like constructing roads, bridges and hydropower projects are being undertaken, therefore there is an urgent need for understanding the pattern of seismicity in this region.</li>
</ul>
</li>
</ul>
</li>
<li><strong>Seismic Hazard Map of India:</strong><br />
<ul style="list-style-type: circle;">
<li>India is one of the highly earthquake affected countries<strong> because of the presence of tectonically active young fold mountains, Himalayas.</strong></li>
<li>India has been divided into <strong>four seismic zones (II, III, IV, and V)</strong> based on scientific inputs relating to seismicity, earthquakes occurred in the past and tectonic setup of the region.<br />
<ul style="list-style-type: disc;">
<li>Previously, earthquake zones were divided into five zones with respect to the severity of the earthquakes but the <strong><a href="/daily-updates/daily-news-analysis/bureau-of-indian-standards-bis-act-2016" target="_blank" rel="noopener">Bureau of Indian Standards</a> (BIS)</strong> grouped the country into four seismic zones by unifying the first two zones.</li>
<li>BIS is the official agency for publishing the seismic hazard maps and codes.</li>
</ul>
</li>
</ul>
</li>
</ul>
<p><a href="http://www.drishtiias.com/images/uploads/1612859443_image5.png" target="_blank" rel="noopener"><img class="content-img" src="http://www.drishtiias.com/images/uploads/1612859443_image5.png" style="display: block; margin-left: auto; margin-right: auto;" width="500" caption="false" /></a></p>
<ul style="list-style-type: square;">
<li><strong>Seismic Zone II:</strong><br />
<ul style="list-style-type: circle;">
<li><strong>Area with minor damage earthquakes</strong> corresponding to intensities V to VI of MM scale (MM-Modified Mercalli Intensity scale).</li>
</ul>
</li>
<li><strong>Seismic Zone III:</strong><br />
<ul style="list-style-type: circle;">
<li><strong>Moderate damage</strong> corresponding to intensity VII of MM scale.</li>
</ul>
</li>
<li><strong>Seismic Zone IV:</strong><br />
<ul style="list-style-type: circle;">
<li><strong>Major damage</strong> corresponding to intensity VII and higher of MM scale.</li>
</ul>
</li>
<li><strong>Seismic Zone V:</strong><br />
<ul style="list-style-type: circle;">
<li>Area determined by pro seismically of certain major fault systems and is seismically the most active region.</li>
<li><strong>Earthquake zone V is the most vulnerable to earthquakes,</strong> where historically some of the country&rsquo;s most powerful shocks have occurred.</li>
<li>Earthquakes with magnitudes in excess of 7.0 have occured in these areas, and have had intensities <strong>higher than IX.</strong></li>
</ul>
</li>
<li><strong>Seismic Waves, Richter Scale and Mercalli scale:</strong> <br />
<ul style="list-style-type: circle;">
<li>Seismic waves are the vibrations from earthquakes that travel through the Earth and are recorded on instruments called <strong>seismographs.</strong><br />
<ul style="list-style-type: disc;">
<li>Seismographs record a zigzag trace that shows the varying amplitude of ground oscillations beneath the instrument.</li>
</ul>
</li>
<li>The earthquake events are scaled either according to the magnitude or intensity of the shock.<br />
<ul style="list-style-type: disc;">
<li>The magnitude scale is known as the<strong> Richter scale.</strong> The magnitude relates to the energy released during the earthquake which is expressed in absolute numbers, 0-10.</li>
<li>The intensity scale or <strong>Mercalli scale</strong> takes into account the visible damage caused by the event. The range of intensity scale is from 1-12.</li>
</ul>
</li>
</ul>
</li>
</ul>
<p><a href="https://pib.gov.in/PressReleseDetailm.aspx?PRID=1696073#:~:text=Scientists%20have%20found%20the%20first,the%20town%20in%201697%20CE." target="_blank" rel="noopener"><strong>Source:PIB</strong></a></p>',
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