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Subject: Geography

  • What is Aurora Borealis?

    Northern Lights, also known as aurora borealis could be visible in regions such as in the northern parts of Illinois and Pennsylvania in the US.

    Try this PYQ:

    What is a coma, in the context of Astronomy?

    (a) Bright half of material on the comet

    (b) Long tail of dust

    (c) Two asteroids orbiting each other

    (d) Two planets orbiting each other

    Aurora

    • Auroras occur when charged particles ejected from the Sun’s surface — called the solar wind — enter the Earth’s atmosphere.
    • While flowing toward Earth, the fast-moving solar wind carries with it the Sun’s magnetic field, which disrupts the magnetosphere — the region of space around Earth in which the magnetic field of our planet is dominant.
    • When the Sun’s magnetic field approaches Earth, the protective magnetic field radiating from our planet’s poles deflects the former, thus shielding life on Earth.
    • However, as this happens, the protective fields couple together to form funnels, through which charged solar wind particles are able to stream down to the poles.
    • At the north and south poles, the charged particles interact with different gases in the atmosphere, causing a display of light in the sky.
    • This display, known as an aurora, is seen from the Earth’s high latitude regions (called the auroral oval), and is active all year round.

    Behind the name

    • In the northern part of our globe, the polar lights are called aurora borealis or Northern Lights and are seen from the US (Alaska), Canada, Iceland, Greenland, Norway, Sweden and Finland.
    • In the south, they are called aurora australis or southern lights and are visible from high latitudes in Antarctica, Chile, Argentina, New Zealand and Australia.

    Where is it observed?

    • Generally, the auroral oval is usually witnessed far up in the Polar Regions or the high latitude regions of Europe, like in Norway.
    • But occasionally, the oval expands, and the lights become visible at lower latitudes.
    • This happens during periods of high solar activity, such as the arrival of solar storms.
    • Solar activities include solar flares, solar energetic particles, high-speed solar wind and Coronal Mass Ejections (CME).

  • Revised height of Mount Everest

    Nepal and China jointly announced the new height of Mount Everest as 8,848.86 meters.

    8,848 metres — the answer to one of the most widely popular quiz questions, and a number drilled into the minds of school students around the world for decades, is set for a revision.

    Mt. Everest

    • Mount Everest or Sagarmatha, Earth’s highest mountain above sea level, is located in the Himalayas between China and Nepal -– the border between them running across its summit point.
    • Its current official elevation – 8,848.86m – places it more than 200m above the world’s second-highest mountain, K2, which is 8,611m tall and located in Pakistan-occupied Kashmir.
    • The mountain gets its English name from Sir George Everest, a colonial-era geographer who served as the Surveyor General of India in the mid-19th century.
    • Considered an elite climbing destination, Everest was first scaled in 1953 by the Indian-Nepalese Tenzing Norgay and New Zealander Edmund Hillary.

    Try this PYQ:

    Q.When you travel to the Himalayas, you will see the following:

    1. Deep gorges
    2. U-turn river courses
    3. Parallel mountain ranges
    4. Steep gradients causing land-sliding

    Which of the above can be said to be the evidences for the Himalayas being young fold mountains?

    (a) 1 and 2 only

    (b) 1, 2 and 4 only

    (c) 3 and 4 only

    (d) 1, 2, 3 and 4

    Everest’s first survey

    • The mission to measure the world’s highest peak was taken up on a serious note in 1847 and culminated with the finding of a team led by Andrew Waugh of the Royal Surveyor General of India.
    • The team discovered that ‘Peak 15’ — as Mt Everest was referred to then — was the highest mountain, contrary to the then-prevailing belief that Mt Kanchenjunga (8,582 m) was the highest peak in the world.
    • Another belief, prevailing even today, is that 8,840 m is not the height that was actually determined by the 19th-century team.
    • That survey, based on trigonometric calculations, is known as the Great Trigonometric Survey of India.

    Why is the height being revised?

    • The height of the summit, however, is known to change because of tectonic activity, such as the 2015 Nepal earthquake.
    • Its measurement over the decades has also depended on who was surveying.
    • Another debate is whether the height should be based on the highest rock point or the highest snow point.

  • Western Disturbances and winters in North

    For the past few days, Chandigarh and its neighbouring states have been experiencing unusually cold days although the night temperatures are normal.

    Try this PYQ:

    Consider the following statements:

    1. The winds which blow between 30°N and 60°S latitudes throughout the year are known as westerlies.
    2. The moist air masses that cause winter rains in the North-Western region of India are part of westerlies.

    Which of the statements given above is/are correct?

    (a) Only 1

    (b) Only 2

    (c) Both 1 and 2

    (d) Neither 1 nor 2

    Temperature anomaly in North

    • Meteorological officials have attributed the trend to the cloud cover in the region which was absent until a few days ago.
    • It is the result of a western disturbance, which has brought about a spell of precipitation in the northwest Himalaya.

    Role of clouds

    • During the day, clouds obstruct the heat from the sun from reaching the surface of the earth, reflecting some of it back into space.
    • This lowers the temperature. Cold winds blowing down from snow-bound areas in the mountains also contribute to the cooling effect.
    • At night, however, clouds act like blankets – they help retain some of the heat energy radiated back by the earth’s surface.
    • Overcast weather at night, thus, increases greenhouse warming.

    What are western disturbances?

    • In northern India, winter rains and clouds are generally caused by moisture-bearing wind systems called western disturbances.
    • They originate and gather moisture over the Mediterranean region and flow eastwards towards the Indian subcontinent.
    • When some of these winds run into mountains of the northwest Himalaya, they are forced upward.
    • At higher altitudes, the temperatures drop and water vapour gets condensed. This leads to cloud formation and eventually rain and snow.

    Other factors for severe winters in North

    • In north India, the huge temperature difference between summers and winters is due to its continentality (distance from seas and oceans).
    • Air from oceans moderates the temperature as it moves onshore, but this effect is missing in continental interiors.
    • As a result, north India has greater seasonal differences as compared to peninsular India.
    • Temperature also reduces rapidly with altitude, and thus, the Himalayan region is colder still.

  • Why has the Northeast Monsoon remained deficient this year?

    Rainfall over the Southern peninsular region has been deficient so far due to prevailing La Nina conditions according to the India Meteorological Department (IMD).

    Try this PYQ:

    Q.La Nina is suspected to have caused recent floods in Australia. How is La Nina different from El Nino?

    1. La Nina is characterized by unusually cold ocean temperature in equatorial Indian Ocean whereas El Nino is characterized by unusually warm ocean temperature in the equatorial Pacific Ocean.
    2. El Nino has an adverse effect on south-west monsoon of India, but La Nina has no effect on monsoon climate.

    Which of the statements given above is/are correct?

    (a) Only 1

    (b) Only 2

    (c) Both 1 and 2

    (d) Neither 1 nor 2

    What is the Northeast monsoon?

    • India receives rainfall during two seasons.
    • About 75 per cent of the country’s annual rainfall is received from the Southwest monsoon between June and September.
    • The Northeast monsoon, on the other hand, occurs from October to December and is a comparatively small-scale monsoon, which is confined to the Southern peninsula.
    • After the complete withdrawal of the Southwest monsoon from the country takes place by mid-October, the wind pattern rapidly changes from the south-westerly to the north-easterly direction.
    • Also called the winter monsoon, the rainfall associated with the Northeast monsoon is important for almost entire South India.

    Why it is important?

    • Tamil Nadu records about 48 per cent (447.4 mm) of its annual rainfall (943.7 mm) during these months, making it the key factor for undertaking agricultural activities and reservoir management in the state.
    • Some South Asian countries such as Maldives, Sri Lanka and Myanmar also record rainfall from October to December.

    Why there are distortions?

    • The majority of districts in Tamil Nadu remain highly rain-deficient up this time.
    • The period after the Southwest monsoon season, from October to December, is the peak time for cyclonic activity in the North Indian Ocean region — covering the Arabian Sea and the Bay of Bengal.
    • The winds associated with the formation of low-pressure systems, depressions, or cyclones influence this monsoon, and therefore, the rainfall.
    • Officials at IMD have linked it to the prevailing La Niña conditions in the Pacific Ocean.

    La Nina  link with the NE monsoon

    • While La Niña conditions enhance the rainfall associated with the Southwest monsoon, it has a negative impact on rainfall associated with the Northeast monsoon.
    • During La Niña years, the synoptic systems — low pressure or cyclones — formed in the Bay of Bengal remain significantly to the north of their normal position.
    • Besides, instead of moving westwards, these systems recurve. As they lie to the north of their normal position, not much rainfall occurs over southern regions like Tamil Nadu.

    Back2Basics: El Nino and La Nina

    • While El Niño (Spanish for ‘little boy’), the more common expression, is the abnormal surface warming observed along the eastern and central regions of the Pacific Ocean (the region between Peru and Papua New Guinea).
    • The La Niña (Spanish for ‘little girl’) is an abnormal cooling of these surface waters.
    • Together, the El Niño and La Niña phenomena are termed as El Niño Southern Oscillation (ENSO).
    • These are large-scale ocean phenomena which influence the global weather — winds, temperature and rainfall. They have the ability to trigger extreme weather events like droughts, floods, hot and cold conditions, globally.
    • Each cycle can last anywhere between 9 to 12 months, at times extendable to 18 months — and re-occur after every three to five years.
    • Meteorologists record the sea surface temperatures for four different regions, known as Niño regions, along this equatorial belt.
    • Depending on the temperatures, they forecast either as an El Niño, an ENSO neutral phase, or a La Niña.

  • Cyclone Nivar to make landfall in TN

    A developing cyclonic disturbance in the Bay of Bengal is expected to become a ‘severe cyclonic storm’ and make landfall in Tamil Nadu.

    Cyclone Nivar

    • The IMD has forecasted the development of a cyclone in the Southwest region of the Bay of Bengal, off Tamil Nadu coast.
    • It has said that it will strengthen into a cyclone. Once intensified, it would acquire its name ‘Nivar’, proposed by Iran.
    • After cyclone Gaja in 2018, this will be the second cyclone to cross Tamil Nadu in the last two years.

    Try this PYQ:

    In the South Atlantic and South-Eastern Pacific regions in tropical latitudes, cyclone does not originate. What is the reason?

    (a) Sea surface temperatures are low

    (b) Inter-Tropical Convergence Zone seldom occurs

    (c) Coriolis force is too weak

    (d) Absence of land in those regions

    Tropical Cyclone

    • A Tropical cyclone is an intense circular storm that originates over warm tropical oceans and is characterized by low atmospheric pressure, high winds, and heavy rain.
    • Cyclones are formed over slightly warm ocean waters. The temperature of the top layer of the sea, up to a depth of about 60 meters, need to be at least 28°C to support the formation of a cyclone.
    • This explains why the April-May and October-December periods are conducive for cyclones.
    • Then, the low level of air above the waters needs to have an ‘anticlockwise’ rotation (in the northern hemisphere; clockwise in the southern hemisphere).
    • During these periods, there is an ITCZ in the Bay of Bengal whose southern boundary experiences winds from west to east, while the northern boundary has winds flowing east to west.
    • Once formed, cyclones in this area usually move northwest. As it travels over the sea, the cyclone gathers more moist air from the warm sea which adds to its heft.

    Must read:

    [Burning Issue] Tropical Cyclones and India

  • Places in news: Mount Vesuvius

    The Italian Culture Ministry announced the discovery of well-preserved remains of two men, who perished during the volcanic eruption of Mount Vesuvius in 79 AD.

    Try this PYQ:

    Q.Consider the following statements:

    1. The Barren Island volcano is an active volcano located in the Indian Territory.
    2. Barren Island lies about 140 km east of Great Nicobar.
    3. The last time the Barren Island volcano erupted was in 1991 and it has remained inactive since then.

    Which of the statements given above is/are correct?

    (a) 1 only

    (b) 2 and 3 only

    (c) 3 only

    (d) 1 and 3 only

    Mount Vesuvius

    • Located in southern Italy near the coastal city of Naples, the 4,203-ft (1,281 metres) tall Vesuvius is the only active volcano in mainland Europe.
    • Vesuvius has been classified as a complex volcano (also called a compound volcano), one that consists of a complex of two or more vents.
    • It typically has explosive eruptions and pyroclastic flows –– defined as a high-density mix of hot lava blocks, pumice, ash and volcanic gas.
    • It has erupted more than 50 times and is considered among the most dangerous volcanoes in the world due to its proximity to Naples and surrounding towns.
    • Its last serious eruption, lasting two weeks, was in 1944 during World War II, which left 26 Italian civilians dead and around 12,000 displaced.

    The eruption of 79 AD

    • In 79 AD, the Roman Empire-era sister cities of Pompeii and Herculaneum were destroyed and buried during a catastrophic eruption of Vesuvius.
    • It was a catastrophic event that destroyed the ancient Roman city of Pompeii and killed around 16,000 people.
    • Pompeii, 8 km away from Vesuvius, served as a resort town on the Bay of Naples for Rome’s elite citizens, consisting of villas, cafes, marketplaces and a 20,000-seat arena.
    • In 63 AD, a major earthquake rattled the city, serving as a warning for the eruption to come. However, few residents bothered to abandon the region, known for its volatility.

  • Chinese dam projects on Brahmaputra and impact on downstream countries

    Scarcity of water in India and China

    • As India and China continue to grow demographically as well as economically amid increased consumption among its citizenry, both nations face water constraints.
    • China, which is home to close to 20 per cent of the world’s population, has only 7 per cent of its water resources.
    • Severe pollution of its surface and groundwater caused by rapid industrialisation is a source of concern for Chinese planners.
    • China’s southern regions are water-rich in comparison to the water-stressed northern part.
    • The southern region is a major food producer and has significant industrial capacity as a consequence of more people living there.
    • India is severely water-stressed as well.
    • Similar to China, India has 17 per cent of the world’s population and 4 per cent of water.
    • As in China, an equally ambitious north-south river-linking project has been proposed in India.

    Impact on downstream states

    • The construction of several dams along the Yarlung (Brahmaputra) river on the Chinese side has been a repeated cause for concern for Indian officials and the local people.
    • China has an ambitious plan to link its south and north through canals, aqueducts and linking of major rivers to ensure water security.
    • In pursuit of these goals, China, being an upper riparian state in Asia, has been blocking rivers like the Mekong and its tributaries, affecting Southeast Asian countries like Thailand, Vietnam, Laos and Cambodia.
    • It has caused immense damage to the environment and altered river flows in the region.
    • China sees these projects as a continuation of their historic tributary system as the smaller states have no means of effectively resisting or even significant leverage in negotiations.

    Challenges for India

    • There are now multiple operational dams in the Yarlung Tsangpo basin with more dams commissioned and under construction. These constructions present a unique challenge for Indian planners.
    • 1) Dams will eventually lead to degradation of the entire basin:
    • Silt carried by the river would get blocked by dams leading to a fall in the quality of soil and eventual reduction in agricultural productivity.
    • 2) The Brahmaputra basin is one of the world’s most ecologically sensitive zones.
    • It is identified as one of the world’s 34 biological hotspots.
    • This region sees several species of flora and fauna that are endemic to only this part of the world.
    • The river itself is home to the Gangetic river dolphin, which is listed as critically endangered.
    • 3) The location of the dams in the Himalayas pose a risk.
    • Seismologists consider the Himalayas as most vulnerable to earthquakes and seismic activity.
    • The sheer size of the infrastructure projects undertaken by China, and increasingly by India, poses a significant threat to the populations living downstream.
    • Close to a million people live in the Brahmaputra basin in India and tens of millions further downstream in Bangladesh.
    • 4) Damming Brahmaputra would result in water security in an era of unprecedented shifting climate patterns.
    • This security extends beyond water, as there is the potential to significantly change the flow rate during times of standoffs and high tensions.

    Way forward

    • Both sides must cease new constructions on the river and commit to potentially less destructive solutions.
    • Building a decentralised network of check dams, rain-capturing lakes and using traditional means of water capture have shown effective results in restoring the ecological balance while supporting the populations of the regions in a sustainable manner.

    Conclusion

    There are alternate solutions to solving the water crisis.  It is in the interest of all stakeholders to neutralise this ticking water bomb.

  • Strengthening the public health capacities in disasters

    The article highlights the importance of the robust public healthcare system for the disaster preparedness and suggests linking it with the primary healthcare.

    Reactive approach to disasters

    • In 2005, India enacted the Disaster Management Act, which laid an institutional framework for managing disasters across the country.
    • Under the Act, reactive, ad hoc measures applied in the event of a disaster, was to be replaced with a systematic scheme for prevention, mitigation, and responding to disasters of all kinds.
    • Disaster management considerations were to be incorporated into every aspect of development and the activities of different sectors, including health.
    • While some headway has indeed been achieved, the approach continues to be largely reactive.
    • Significant gaps remain particularly in terms of medical preparedness for disasters.

    Medical preparedness for disasters

    • Two important lessons emerge:-
    • First, health services and their continuing development cannot be oblivious to the possibility of disaster-imposed pressures.
    • Second, the legal framework for disaster management must push a legal mandate for strengthening the public health system.

    Role of private health sector during disaster

    • Instances of overcharging during Covid illustrates how requisitioning of private sector services during disasters can hardly be a dependable option in the Indian context.
    • This is particularly important since the future development of hospital care services is being envisaged chiefly under publicly financed health insurance, which would very likely be private-sector led.
    • The Indian private sector landscape, characterised by weak regulation and poor organisation, is incapable for mounting a strong and coordinated response to disasters.
    • During disasters, the limited regulatory ability could be further compromised.
    • While publicly financed insurance could be a medium to introduce some order into this picture, a large majority of private hospitals in the country are small enterprises which cannot meet the inclusion criteria for insurance.
    • Many of these small hospitals are also unsuitable for meeting disaster-related care needs.
    • Punitive action against non-compliant requisitioned hospitals becomes tricky during disasters since health services are already inadequate.
    • Private hospitals are known to prefer lucrative and high-end ‘cold’ cases, especially under insurance, and are generally averse to infectious diseases and critical cases with unpredictable profiles.

    Need for strong public sector capacities

    • Due to the above-cited limitations of the private sector, strong public sector capacities are imperative for dealing with disasters.
    • While the Disaster Management Act does require States and hospitals to have emergency plans, medical preparedness is a matter of policy, and, therefore, gaps are pervasive.
    • There is a strong case for introducing a legal mandate to strengthen public sector capacities via disaster legislation.
    • There is also scope for greater integration of disaster management with primary care.
    • Primary care stands for things such as multisectoral action, community engagement, disease surveillance, and essential health-care provision, all of which are central to disaster management.

    Way forward

    •  Evidence supports the significance of robust primary care during disasters, and this is particularly relevant for low-income settings.
    • Synergies with the National Health Mission, concurrently with the Disaster Management Act in 2005, could be worth exploring.
    • Interestingly, the National Health Mission espouses a greater role for the community and local bodies, the lack of which has been a major criticism of the Disaster Management Act.
    • Making primary health care central to disaster management can be a significant step towards building health system and community resilience to disasters.

    Consider the question “Robust public healthcare system is indispensable for the disaster preparedness which could be achieved through making the primary healthcare central to the disaster management. Comment.

    Conclusion

    While the novel coronavirus pandemic has waned both in objective severity and subjective seriousness, valuable messages and lessons lie scattered around. It is for us to not lose sight and pick them up.

  • Cyclonic storms during October

    October to December period is among the favourable months for the development of cyclones in the Bay of Bengal and the Arabian Sea. This year, however, October passed without witnessing a cyclonic storm.

    Must read: [Burning Issue] Tropical Cyclones and India

    https://www.civilsdaily.com/burning-issue-tropical-cyclones-and-india/

    When do cyclones form and hit Indian coasts?

    • About 80 cyclones are formed around the world annually, out of which five are formed in the Bay of Bengal and the Arabian Sea, together known as the North Indian Ocean.
    • India’s east and west coasts are prone to cyclones with the maximum associated hazards—rain, heavy winds and storm surge— faced by coastal districts of West Bengal, Odisha and Andhra Pradesh.
    • Cyclones in the North Indian Ocean are bi-modal in nature, that is, they occur during two seasons— April to June (pre-monsoon) and October to December (post-monsoon).
    • Of these, May and November remain the most conducive for the development of cyclones.

    When have cyclones skipped October, previously?

    • Cyclonic disturbances— either in the form of a well-marked low pressure, depression or a deep depression— are common in October.
    • Ocean disturbances enter the Bay of Bengal from the South China seaside and head towards the Indian coast.
    • IMD officials have attributed it to the weak La Nina conditions along the equatorial Pacific Ocean.
    • Cooler than normal sea surface temperatures over this region—termed as La Nina— has been prevailing since August this year.

    Madden Julian Oscillation (MJO)

    • Because Madden Julian Oscillation (MJO) was positioned in a favourable phase, the low-pressure systems intensified maximum up to a deep depression.
    • MJO is kind of an eastward-moving cyclic weather event along the tropics that influences rainfall, winds, sea surface temperatures and cloud cover. They have a 30 to 60-day cycle.
    • Most importantly, there was the high wind shear noted between the different atmospheric levels, last month.
    • The vertical wind shear— created due to significant wind speed difference observed between higher and lowers atmospheric levels— prevented the low-pressure systems and depression from strengthening into a cyclone.

  • Using the crucial expertise of CAPFs

    The article emphasises the role played by the CAPFs in dealing with the disasters.

    Dealing with the disasters

    • When disaster strikes our country, be it natural or man-made, the government summons the Central Armed Police Forces (CAPFs) to carry out the task of overcoming the disaster.
    • The CAPFs help in carrying out rescue and relief operations, and also mitigates the pains and problems arising out of the disaster.

    Role played by CAPFS during Covid

    • CAPFs comprise the Central Reserve Police Force (CRPF), Border Security Force, Central Industrial Security Force, Sashastra Seema Bal, Assam Rifles and the ITBP.
    • Even before the country got to know about the COVID-19, the Indo-Tibetan Border Police (ITBP) had already set up its 600-bed quarantine centre in Chawla on the outskirts of New Delhi.
    • The Union Ministry of Health and Family Welfare had roped in specialists from the Safdarjung Hospital to coordinate with ITBP officials.
    • Doctors and paramedical personnel of other CAPFs were also roped in.
    • The expertise acquired by ITBP personnel and the Standard Operating Procedure prepared by the ITBP came handy for the States and other police forces in establishing their own quarantine centres and COVID-19 hospitals.

    Role of NDRF during Covid-19

    • NDRF personnel are wholly drawn from the CAPFs.
    • So, they form a good reserve of trained personnel when they go back to their parent force after their stint with NDRF.
    • With 12 battalions of the NDRF— each comprising 1,149 personnel — spread across the country, its experts have the core competency to tackle biological disasters like COVID-19.
    • Such personnel can be deployed at quarantines centres after short-term courses.
    • A proposal mooted by NITI Aayog last year, to conduct a bridge course for dentists to render them eligible for the MBBS degree, could be revived, and such doctors could be on stand-by to help in such emergency crises.

    Conclusion

    It is these CAPF personnel who give a semblance of existence of government administration even in the remotest corners of the country. Their versatile experience can be utilised to the nation’s advantage.

    B2BASICS:

    CAPF

    The Central Armed Police Forces refers to uniform nomenclature of five security forces in India under the authority of Ministry of Home Affairs. Their role is to defend the national interest mainly against the internal threats.