As per the data from US National Snow and Ice data Center (NSIDC), the combined extent of Arctic and Antarctic sea ice dropped from 15.93 million sq km to 15.76 million sq km in marking a record low. 

Sea Ice

• About: Sea ice refers to the free-floating ice in the polar regions. While it generally expands during the winter and melts in the summers, some sea ice remains year-round. 
  • Note that this is different from icebergs, glaciers, ice sheets, and ice shelves, which form on land.
• Global Distribution: Arctic Sea Ice: Covers 40% of total global sea ice. Antarctic Sea Ice: Accounts for 60%, with larger seasonal fluctuations.
• Role in Climate Regulation
  • Enhancing Albedo: Reflects solar radiation, preventing excessive heating.
  • Absorbing Ocean Heat: Reduces average ocean temperature by storing subsurface heat.
  • Preventing Ocean Acidification: Lowers ocean temperature, reducing CO₂ absorption, helping protect coral reefs.

Extent of ice dip in Arctic and Antarctic

• Overall Decline:  77,800 sq km of sea ice lost per year since the late 1970s (NSIDC estimate).
• Arctic Sea Ice Decline: 1981-2010: Shrinking at a rate of 12.2% per decade (minimum extent in September).
• Antarctic Sea Ice Trends
• • Before 2015: Slight year-on-year increase observed.
  • 2014-2017: Lost 2 million sq km of ice—4 times the size of Spain

Reasons behind the dip

• Transformed Wind Pattern: More vulnerable to wind-driven breakup due to its mobility and thinness. Warmer air and waters accelerated melting at the end of the southern hemisphere summer.
• Ice shelf melting: Higher temperatures caused the edges of Antarctic ice sheets to erode.
• Atmospheric changes: The studies suggested the subsurface warming of the Southern Ocean has pushed the Antarctic sea ice melt. 
• Higher air temperature: The regions like the Barent sea witnessed some storms due to which the Arctic ice has become thinner and more fragile over the years. 
  • Also, higher than usual air temperatures in areas such as Svalbard, Norway resulted in further loss of sea ice.

Impact of Declining Sea Ice Cover

• Increased Heat Absorption: Less ice means more ocean surface exposed, absorbing more solar radiation. Loss of reflective ice cover accelerates polar warming.
• Disruption of Ocean Circulation: Freshwater from melting ice reduces salinity and density, slowing deep-water currents. Weakening of ocean overturning affects global climate, marine ecosystems, and ice shelf stability.

Conclusion

Understanding the contributing factors for dip in ice cover and its potential consequences is essential for developing effective mitigation and adaptation strategies. 

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