ANTARCTICA’S SEA ICE

Disclaimer: Copyright infringement not intended.

Context

• As of date, Antarctica's sea ice extent reached a historic low of about 14.2 million square kilometers, significantly below the normal extent of 16.7 million square kilometers for this time of year.
• The sea ice cover in Antarctica has deviated by over six standard deviations, indicating a highly anomalous event.

Highlights

Causes of Reduced Sea Ice Extent

• Impact of High Temperatures in the Northern Hemisphere: Correlation with northern hemisphere temperatures: The northern hemisphere's warming has repercussions for Antarctica's climate, leading to the reduction in sea ice cover.
• Influence of warm air from the north: The transportation of warm air from the northern regions to Antarctica is contributing to the low ice condition.
• Southern Ocean and Climate Change: The Southern Ocean encircling Antarctica normally freezes to form sea ice during peak winter (September or early October) and melts during summer (December to February).

Alarming trend

• From 2015 onwards, there has been a significant drop in winter sea ice extent, compared to record highs observed in the years 2012 to 2014.

Implications and Climate Concerns

Environmental Impact

• Impact on marine life: The record low sea ice extent poses potential threats to marine life accustomed to colder temperatures.
• Feedback loop: Reduced sea ice leads to a warmer ocean surface, causing further ice melt and potential disruption to ecosystems.

Glacial and Ice Shelf Stability

• Melting of glaciers and ice shelves: Warmer ocean waters can accelerate the melting and thinning of glaciers and ice shelves that extend over the ocean.
• Destabilization risk: As floating ice shelves disintegrate, glaciers may break up, leading to increased ice flow into the ocean and further sea level rise.

Rising Global Sea Levels

• Existing sea level rise: The global mean sea level has already increased by 21-24 centimeters since 1880, according to the National Aeronautics and Space Administration (NASA).
• Potential for further rise: Continued loss of ice from Antarctica could exacerbate the sea level rise, impacting coastal areas and human settlements worldwide.

Conclusion

• Urgent need for action: The unprecedented decrease in Antarctica's sea ice extent highlights the importance of addressing climate change on a global scale.
• Environmental implications: The warming of Antarctica's climate and its consequences for the ecosystem necessitate attention and measures to mitigate further damage.
• Climate change mitigation and adaptation: Sustainable practices, international cooperation, and policy interventions are crucial in combatting the challenges posed by global warming and its effects on the polar regions.

Antarctica

Location and Size

• Antarctica is the southernmost continent on Earth, situated entirely within the Antarctic Circle.
• It covers an area of approximately 14 million square kilometers (5.4 million square miles), making it the fifth-largest continent.

Climate

• Antarctica is the coldest place on Earth, with average temperatures ranging from about -60°C (-76°F) in winter to -20°C (-4°F) in summer.
• It is considered a polar desert, with very little precipitation. The interior receives less than 50 millimeters (2 inches) of snowfall annually.

Ice Sheet and Ice Volume

• Antarctica contains about 70% of the world's freshwater ice, with an estimated volume of around 26.5 million cubic kilometers (6.4 million cubic miles).
• The Antarctic ice sheet averages about 2,100 meters (7,000 feet) in thickness, but in some areas, it can be as thick as 4,776 meters (15,670 feet).

Research Stations

• Multiple countries operate scientific research stations on the continent, conducting studies on various disciplines, including climate, geology, biology, and astronomy.
• The number of research stations fluctuates throughout the year, with a peak population during the summer months.

Flora and Fauna

• Due to its extreme cold and isolation, Antarctica has limited biodiversity. Few plants, such as mosses and lichens, can survive in its coastal regions.
• The surrounding Southern Ocean, however, is rich in marine life, including various species of fish, krill, seals, and several types of penguins.

Antarctic Treaty System

• Antarctica is governed by the Antarctic Treaty System, which came into effect in 1961. It designates the continent as a scientific preserve and prohibits military activities, mineral mining, and nuclear testing.
• The treaty has been signed by 54 countries, ensuring that Antarctica is used exclusively for peaceful and scientific purposes.

Ozone Hole

• Antarctica is famously associated with the annual depletion of the ozone layer during the Southern Hemisphere's spring (September to November).
• The "ozone hole" is caused by the release of human-made chlorofluorocarbons (CFCs) and other ozone-depleting substances, leading to significant environmental concerns.

Inaccessibility

• Antarctica is one of the most remote and difficult-to-access places on Earth. Harsh weather conditions and the presence of icebergs and pack ice make navigation challenging.
• Only a few vessels, including icebreakers, can access certain areas, and air travel is limited to specific research bases and runways.

https://www.downtoearth.org.in/news/climate-change/antarctica-s-sea-ice-is-at-its-lowest-extent-ever-recorded-90833