GEOGRAPHY

Studies have shown that the 40-year low of Antarctic sea ice is related to thermal action


In February, Antarctic sea ice covered 1.92 million square kilometers, the lowest in four decades. What is it that brings antarctic sea ice range to an “all-time low”? On April 19, Advances in Atmospheric Science released the latest study in the form of a cover article, in which yang Qinghua’s team of sun yat-sen university professors, Liu Jiping, a professor at the State University of New York, and Yu Lejiang, an associate researcher at the China Polar Research Center, and other researchers analyzed the minimum event of sea ice range from the perspective of sea ice revenue and expenditure. The results showed that in the southern hemisphere summer, thermodynamic action dominated sea ice changes; in spring, thermal and dynamic processes together influenced sea ice changes.

Antarctic sea ice is an important component of the polar climate system, influencing the flux exchange at the atmosphere-ocean interface and participating in complex atmosphere-sea-ocean interactions in the Southern Ocean. In the past 40 years, contrary to the rapid decline of Arctic sea ice, the Antarctic sea ice range has shown a steady and slow growth trend, and then it has decreased rapidly, and the sea ice range has dropped to a record in the summer of 2017. But only five years later, that record for the lowest value was broken again.

Lead author Wang Jinfei, a doctoral student at Sun Yat-sen University’s School of Atmospheric Sciences, said antarctic sea ice melted early in early September 2021 and that the range of sea ice began to be significantly below average since February 8, 2022. Summer Antarctic sea ice range anomalies are mainly located in the West Amundsen Sea, east Ross Sea, western Antarctic Peninsula, North Weddell Sea and northwest Indian Ocean, and spring sea ice anomalies are mainly located in the West Weddell Sea, The Belinskojin Sea and the Eastern Indian Ocean.

“In the summer, the heat transfer to the poles and the net heat flux on the surface are unusually high, resulting in increased melting of sea ice. In the spring, dynamics cause amundsen Sea Ice to be transported northward and melted, accompanied by a decrease in coastal sea ice thickness, while the surface net heat flux primarily melts Weddell Sea Ice. Wang Jinfei said.

The early and accelerated melting of Antarctic sea ice could have a huge impact on the polar climate and ecosystems, and could also face a huge catastrophe for penguins living in antarctica.

It is understood that the emperor penguin needs just the right thickness of sea ice when hatching the cubs, and the time of sea ice melting is advanced, resulting in the emperor penguin baby being covered with mud and easy to die of temperature loss. The rapid melting of sea ice can also cause baby penguins to get into the water too early, and when they have not yet changed into waterproof feathers, the mortality rate will be higher. “The back of a lone penguin on the cover of this issue on the surface of the gradually melting ice hopes to make everyone more concerned about the threats facing the Antarctic climate and ecosystem.” Lin Zheng, editor of Advances in Atmospheric Science, said.

Yang Qinghua said that this study only conducts a preliminary analysis of the lowest antarctic sea ice event from the local scale, and further research is needed on the factors leading to these local atmospheric and ocean anomalies, such as the remote correlation between the middle and low latitude sea temperature anomalies and the atmospheric circulation at high latitudes, the stability of ocean formations in the Southern Ocean, the natural variability and the contribution of human activities.

191650363390_.pic.jpg

Advances in Atmospheric Science paper cover (Courtesy of the editorial board of the journal)

“At the same time, the low values of Antarctic sea ice in 2016-2017 and 2021-2022 may indicate that Antarctic sea ice has entered a new phase of extreme events.” Yang Qinghua said. (Source: China Science Daily Gao Yali)

Related paper information:https://doi.org/10.1007/s00376-022-2087-1



Source link

Related Articles

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to top button