SHRINKING ANTARCTICA’S SEA ICE (Syllabus: GS Paper 1 - Geography)

News-CRUX-10     28th July 2023        
Samadhaan

Context: As the northern hemisphere shatters new temperature records, Antarctica in the southern hemisphere is also bearing the brunt of warm temperatures.


Key Points

  • Despite it being peak winter in the southern hemisphere, the sea ice cover in Antarctica has deviated from the 1991-2020 average by over six standard deviations (SD). 
    • One SD is a measure of how much an observation deviates from the mean. 
  • The Southern Ocean that encircles Antarctica freezes to form sea ice every year, reaching its maximum at the end of winter, which is September or early October in the Southern Hemisphere. 
  • In the summer months, which last from December to February, the sea ice melts due to warmer temperatures and longer hours of sunlight.
  • The lack of sea ice is causing temperatures to warm further. 
  • The bright surface of sea ice is known to reflect incoming sunlight into space.
  • Winds from the north are transporting warm air to Antarctica. This could be contributing to the low ice condition.
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