In November 2020,the eastern Arctic experienced an extensive extreme warm anomaly(i.e.,the second strongest case since 1979),which was followed by extreme cold conditions over East Asia in early winter.The observed Ar...In November 2020,the eastern Arctic experienced an extensive extreme warm anomaly(i.e.,the second strongest case since 1979),which was followed by extreme cold conditions over East Asia in early winter.The observed Arctic warm anomaly in November 2020 was able to extend upwards to the upper troposphere,characterized as a deep Arctic warm anomaly.In autumn 2020,substantial Arctic sea-ice loss that exceeded the record held since1979,accompanied by increased upward turbulent heat flux,was able to strongly warm the Arctic.Furthermore,there was abundant northward moisture transport into the Arctic from the North Atlantic,which was the strongest in the past four decades.This extreme moisture intrusion was able to enhance the downward longwave radiation and strongly contribute to the warm conditions in the Arctic.Further analysis indicated that the remote moisture intrusion into the Arctic was promoted by the large-scale atmospheric circulation patterns,such as the wave train propagating from the midlatitude North Atlantic to the Arctic.This process may have been linked to the warmer sea surface temperature in the midlatitude North Atlantic.展开更多
基金supported by the Guangdong Major Project of Basic and Applied Basic Research [grant number 2020B0301030004]the National Natural Science Foundation of China [grant numbers 42025502 and 41875118]+1 种基金the Research Council of Norway project BASIC [grant number 325440]the State Scholarship Fund of the China Scholarship Council [grant number 202109045003]
文摘In November 2020,the eastern Arctic experienced an extensive extreme warm anomaly(i.e.,the second strongest case since 1979),which was followed by extreme cold conditions over East Asia in early winter.The observed Arctic warm anomaly in November 2020 was able to extend upwards to the upper troposphere,characterized as a deep Arctic warm anomaly.In autumn 2020,substantial Arctic sea-ice loss that exceeded the record held since1979,accompanied by increased upward turbulent heat flux,was able to strongly warm the Arctic.Furthermore,there was abundant northward moisture transport into the Arctic from the North Atlantic,which was the strongest in the past four decades.This extreme moisture intrusion was able to enhance the downward longwave radiation and strongly contribute to the warm conditions in the Arctic.Further analysis indicated that the remote moisture intrusion into the Arctic was promoted by the large-scale atmospheric circulation patterns,such as the wave train propagating from the midlatitude North Atlantic to the Arctic.This process may have been linked to the warmer sea surface temperature in the midlatitude North Atlantic.
