Deep-winter heatwave in Antarctica

Source- This post on Deep-winter heatwave in Antarctica has been created based on the article “What’s causing Antarctica’s deep-winter heatwave, what could be its fallout?” published in “Indian Express” on 9 August 2024.

Why in News?

Antarctica is currently experiencing a significant heatwave during its deep winter, with temperatures unusually high for this time of year.

What is happening?

In East Antarctica, where deep-winter temperatures typically range between -50°C to -60°C, the current temperatures are between -25°C and -30°C. These temperatures are about 10°C higher than normal, with some days seeing increases of up to 28°C.

Reason behing occurance of this heatwave:

1. Weakened Polar Vortex: The polar vortex is a band of cold air that usually traps cold temperatures over Antarctica during the winter. However, this year, large-scale atmospheric waves have disturbed the vortex, causing it to weaken.

2. Warm Air Infiltration: As the polar vortex weakened, it allowed warmer air to enter Antarctica, causing the unexpected rise in temperatures.

3. Reduced Sea Ice: The reduction in the extent of Antarctica Sea ice is another contributing factor. Sea ice reflects sunlight and keeps the air cool. With less ice, the region absorbs more heat, leading to warmer temperatures.

Potential Consequences of the Heatwave

1. Ice Sheet Melting

i) Antarctic Ice Sheet: The heatwave is likely to cause further melting of the Antarctic Ice Sheet, which contains more than 60% of the world’s freshwater.

ii) Sea Level Rise: Melting ice sheets could raise global sea levels, potentially submerging coastal cities and displacing millions of people. Even a small rise in sea level could have severe consequences for populations living near the coast.

2. Impact on Global Climate

i) Disruption of Ocean Circulation: The melting ice affects the global ocean circulation system, which helps regulate climate. Freshwater from the ice reduces the salinity and density of ocean water, slowing down the circulation.

ii) Intensified Global Warming: A slower ocean circulation system means oceans will absorb less heat and CO2, potentially leading to more extreme weather events like floods and droughts.

UPSC Syllabus: Environment