Stories
Goa Scientists Uncover 250-Year History of Antarctic Polynya Events
- •Researchers in Goa reconstructed 250 years of Antarctic polynya events, revealing the Maud Rise Polynya is a recurring phenomenon, not a rare one-time occurrence.
- •The study, published in "The Cryosphere," identified 25 potential opening events of the Maud Rise Polynya between 1774 and 2016 using a 122-meter ice core.
- •Polynyas are open-water areas within sea ice, crucial for heat and gas exchange, influencing deep-ocean convection, carbon cycling, and ocean circulation.
- •Scientists developed a polynya index from four ice-core indicators to overcome limitations in understanding pre-satellite era events.
- •The findings suggest recurring polynya activity due to persistent favorable atmospheric and oceanic conditions, offering insights into climate change impacts.
Key Questions Answered
Researchers at the National Centre for Polar and Ocean Research analysed a 122-metre ice core drilled at Djupranen Ice Rise in coastal Dronning Maud Land. They developed a polynya index by combining four ice-core indicators including sea-salt sodium flux, oxygen isotope ratios, deuterium excess, and annual snow accumulation to cover the period from 1774 to 2016.
The Maud Rise Polynya, also known as the Weddell Polynya, is a large area of open water surrounded by sea ice located over the Maud Rise seamount in the eastern Weddell Sea. It is considered significant because open-ocean polynyas facilitate heat and gas exchanges between the ocean and atmosphere, and they can influence deep-ocean convection, carbon cycling, and ocean circulation.
The Maud Rise Polynya reached an extent of more than 300,000 square kilometres during 1974-1976, and it later reappeared on a smaller scale during the winters of 2016 and 2017 when the opening exceeded 40,000 square kilometres.
