ANTARCTICA’S DEEP-WINTER HEATWAVE: CAUSES AND CONSEQUENCES

Why in the news?

  • Antarctica is experiencing an unprecedented deep-winter heatwave due to a weakened polar vortex and reduced sea ice.
  • This could accelerate ice sheet loss and impact global weather patterns.
ANTARCTICA'S DEEP-WINTER HEATWAVE: CAUSES AND CONSEQUENCES - UPSCsource:britanica

About Current Heatwave in Antarctica:

  • Record Temperatures: Antarctica is experiencing a deep-winter heatwave, with temperatures 10°C above average and up to 28°C higher on some days.
  • Temperature Ranges: In East Antarctica, temperatures are between -25°C and -30°C, compared to the usual -50°C to -60°C.

Causes of the Heatwave:

  • Weakened Polar Vortex: The disruption of the polar vortex has allowed warmer air to enter Antarctica. This disturbance, caused by large-scale atmospheric waves, is rare and expected only once every two decades.
  • Reduced Sea Ice: The decrease in Antarctic sea ice, which was at a record low in June, contributes to higher temperatures. Less ice means less sunlight is reflected back to space and more heat is absorbed.

Potential Impacts:

  • Ice Sheet Loss: The heatwave could accelerate the loss of the Antarctic Ice Sheet, which contributes to rising global sea levels. Recent heat waves have already caused significant ice loss, including a major ice sheet collapse in 2022.
  • Global Effects: Melting ice impacts global ocean circulation, reducing salinity and density, which disrupts heat and carbon transport. This can intensify global warming and increase extreme weather events.
Key Facts about Antarctica:

  • Location: Southernmost continent on Earth, covered by a vast ice sheet.
  • Climate: Experiences extreme cold temperatures, with seasonal melting of sea ice every summer (December to February).
  • Ice Coverage: Sea ice melts during the austral summer and refreezes in winter.
  • Role: Crucial in influencing global atmospheric and oceanic systems due to its ice sheet’s impact on sea levels and climate.
  • Research: Vital for climate and environmental research due to its unique and extreme conditions.

About Marine Heat Waves (MHWs):

  • Definition: An extreme weather event where sea surface temperatures rise 3-4°C above the average for at least five consecutive days.
  • Duration: MHWs can persist for weeks, months, or even years.
  • Impact: Can lead to significant ecological and environmental consequences, including coral bleaching, disruption of marine ecosystems, and impact on fisheries.
  • Monitoring: Tracked and reported by agencies like the National Oceanic and Atmospheric Administration (NOAA).
  • Significance: Increasingly common due to climate change, affecting marine biodiversity and coastal communities.