Arctic Amplification
Source: The Hindu
GS III:  Environment and Conservation

What is discussed under Arctic Amplification?

1. Polar amplification?
2. What is arctic amplification?
3. Causes of arctic amplification
4. Consequences of arctic warming 
5. Impact of arctic warming on India

Why in News?

• Researchers from the Finnish Meteorological Institute concluded from their study published in Communications Earth & Environment that the Arctic is warming four times faster than the rest of the earth.
• The warming is more concentrated in the Eurasian part of the Arctic.
• The Barents Sea north of Russia and Norway is warming at an alarming rate of seven times faster than the global average.

What Is Polar Amplification?

• The phenomenon of any change in the net radiation balance, such as greenhouse gas intensification and solar output, causing a greater change in temperature near the poles than the global average.

  

• Commonly referred to as the ratio of polar warming to tropical warming.
• The greenhouse effect will cause higher-than-normal surface temperatures.
• The poles will be warmer and equatorial areas will be cooler than their local net radiation balances would predict in places where the atmosphere or an ocean is able to transfer heat poleward.
• Therefore, when the global mean temperature is lower than a reference climate, the poles will cool the most.
• When the global mean temperature is greater, the polar regions will warm the most.
• Two types of polar amplification:
  • Arctic amplification: Polar amplification of the earth’s north pole.
  • Antarctic amplification: Polar amplification of the earth’s south pole.
• The enormous Southern Ocean, which surrounds Antarctica, is absorbing most of the excess heat in the atmosphere.
• So, Antarctic warming is not much alarming now.

What Is Arctic Amplification?

• Northern latitudes have more pronounced polar amplification
• The Arctic region consists of all landmasses and seas north of 66.5° latitude (arctic circle).
• Over the past 30 years, the Arctic has warmed at roughly four the rate as the entire globe.
• As per WMO, Verkhoyansk, a Siberian town experienced the highest temperature of 38°C, the highest ever recorded temperature in the Arctic region.  
• Global warming and climate change are impacting the Arctic more than the rest of the world.

Causes of Arctic Amplification 

Global warming

• Global warming has accelerated due to human activities raising the planet’s average temperature by 1.1 degrees Celsius.

Ice–albedo feedback

• It is a measure of how much light that hits a surface (area of ice caps, glaciers, and sea ice) is reflected without being absorbed.
  • Albedo: Measure of reflectivity of the surface
• Ice is very reflective, therefore, some of the solar energy is reflected back to space.
• As the sea ice melts, the Arctic Ocean will be more capable of absorbing solar radiation, thereby driving the amplification.
• Ice–albedo feedback is responsible for 40% of polar amplification.

Laps rate

• It is the rate at which the temperature drops with elevation decreases with warming.
• Lapse rate feedback is 15% of polar amplification.

Changing Ocean currents

• Ocean currents normally bring in warmer water from the Pacific, and colder water exits out of the Arctic into the Atlantic.
• Such currents may be changing because more melting ice is injecting the Arctic Ocean with freshwater. 

Changes in cloud cover

• Spring season exhibits significant trends in Arctic average cloudiness.
• Decreased cloud cover causes surface cooling because clouds have a warming influence in spring.

Changes in atmospheric water vapour content 

• Enhanced surface moisture fluxes associated with sea ice reductions drive humidity increase.

Declining sea ice cover and thickness

• The polar ice is on the water; as the oceans warm, warmer water helps melt the Arctic ice.

Consequences of Arctic Warming 

• Thinning of Greenland ice sheet
• Rise in sea level
• Impact on biodiversity:
  • The acidification of water and changes in the salinity levels are impacting biodiversity, including the marine and the dependent species.
• Thawing of permafrost
  • The permafrost thawing releases carbon and methane, the major greenhouse gases responsible for global warming.
• Increase in rainfall
• Death of fauna
• Disease outbreak
  • The permafrost melt will release dormant viruses and bacteria that might potentially cause sickness.
  • In 2016, thawing permafrost in Siberia caused an anthrax epidemic that claimed approximately 2,000 000 reindeer.

Impact of Arctic Warming on India

• According to the World Meteorological Organization’s report,  ‘State of Global Climate in 2021’, the sea level along the Indian coast is rising faster than the global average rate.
• The melting of sea ice in the northern areas, particularly the Arctic, is one of the main causes of this increase.
• The link between changing Arctic and monsoons in the subcontinent is growing in importance due to:
  • The extreme weather events the country faces
  • The heavy reliance on rainfall for water and food security
• A team of Indian and Norwegian scientists published a study in 2021 titled “A possible relation between Arctic sea ice and late season Indian Summer Monsoon Rainfall Extremes.”
• According to the study, reduced sea ice in the Barents-Kara sea region can cause extreme rainfall events in the second half of the monsoon, in September and October.
• Changes in atmospheric circulation due to melting sea ice and the Arabian Sea temperatures cause increased moisture and intense rainfall events. 

Steps taken by India

• In 2014, India deployed IndARC, India’s first moored-underwater observatory in the Kongsfjorden fjord, Svalbard.
• Aim of the observatory is to monitor the impact of the changes in the Arctic Ocean on the tropical processes such as the monsoons. 

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