Antarctica’s Deep-Winter Heatwave

Antarctica is experiencing its second intense winter heatwave in two years, with ground temperatures averaging 10°C above normal since mid-July and reaching up to 28°C higher on some days.

Status of Temperatures in East Antarctica

• Current Temperature Levels: Temperatures in East Antarctica range between minus 25°C to minus 30°C.
• Typical Winter Temperatures: Normally, deep-winter temperatures in this region vary between minus 50°C to minus 60°C.

About Heat Wave

• Heat Wave: A heat wave is a period of unusually high temperatures, exceeding normal maximum temperatures for the summer season.
• Timing: Heat waves commonly occur between March and June, and occasionally extend into July.
• Trends: Global climate change is leading to more frequent and intense heat waves, with higher peak temperatures and longer durations.

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Reasons for the Heatwave in Antarctica

• Weakening of the Polar Vortex

  • The primary culprit behind the heatwave is the weakening of the polar vortex.
    • The polar vortex is a band of cold air and low-pressure systems that circulates around the Earth’s poles in the stratosphere.
  • Normally, this vortex keeps cold air trapped and prevents warm air from entering.
  • However, large-scale atmospheric waves disrupted the vortex this year, allowing warm air to infiltrate the region.

• Reduced Antarctic Sea Ice

  • Sea Ice Role: Sea ice helps maintain low temperatures in polar regions by reflecting sunlight back into space and acting as a barrier between the cold air and warmer water below.
    • A significant decline in Antarctic sea ice extent contributed to the heatwave.
      • Less sea ice means more sunlight is absorbed, leading to warmer temperatures.

• Accelerated Warming in Antarctica

• • Antarctica is warming at a rate of 0.22°C to 0.32°C per decade, nearly twice as fast as the global average due to climate change. 
    • This rapid warming makes the region more susceptible to extreme weather events like heat waves.
      • The overall trend of global warming exacerbates the impact of other factors.

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Consequences of Antarctica’s Heatwave

• Ecosystem Disruption

• • Biodiversity Impact: The heatwave could disrupt Antarctic ecosystems, affecting species that depend on cold, stable conditions. 
    • This could lead to changes in the food chain and impact global biodiversity.
  • Habitat Loss: As ice melts, habitats for cold-adapted species like penguins and seals may shrink, leading to potential declines in their populations.

• • Antarctic Ice Sheet Impact: The heatwave could accelerate the loss of the Antarctic Ice Sheet, which, along with the Greenland Ice Sheet, is crucial for global ice reserves.
    • The Antarctic Ice Sheet is vital for global ocean circulation, which distributes heat, carbon, nutrients, and freshwater.
  • Global Sea Level Threat: If melted, the Antarctic Ice Sheet, which holds over 60% of the world’s freshwater, could significantly raise global sea levels and displace millions living near coastlines.

• Feedback Loops and Further Wrming

  • Albedo Effect: The loss of ice reduces the Earth’s albedo, or its ability to reflect sunlight. 
    • Less ice means more sunlight is absorbed by the ocean, leading to further warming and accelerated ice melt.
  • Potential Runaway Warming: This process could create a feedback loop, where warming leads to more ice melt, which in turn leads to further warming, potentially pushing the Antarctic climate system toward irreversible changes.

• Global Climate Implications

• • Extreme Weather: Changes in Antarctic conditions could influence global weather patterns, leading to more extreme weather events such as heatwaves, storms, and floods in other parts of the world.
  • Impact on Global Carbon Cycle: The disruption of the ocean circulation system could affect the global carbon cycle, potentially leading to higher concentrations of carbon dioxide in the atmosphere and exacerbating global warming.
    • Slowing Circulation: Melting ice is reducing surface water salinity and density, slowing down ocean circulation and impacting climate regulation.

Significance of Antarctica

• Climate Regulation: 
  • Climate regulation: Antarctica ice sheet reflects a lot of solar energy which helps to control temperature of the earth. 
  • Ocean circulation: It plays a major role in ocean circulation which impacts the climate patterns around the world. 
• Freshwater Storage: Antarctica ice sheet is the largest reservoir of freshwater on the earth.
  • It holds around 60 metres of sea level equivalent. 
• Biodiversity: Despite its harsh climatic condition, it supports various wildlife including penguins, seals, and various seabirds.
• Scientific Research: Ice cores in Antarctica provide useful data on Earth’s climate history over a million of years. 
  • It acts as a natural laboratory for studying life in harsh environments and understanding the whole ecosystem. 

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India’s Endeavour at Antarctica

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