Changes of relationship between Arctic sea ice and East Asian winter monsoon under global warming and their mechanisms
In order to further understand the relationship between Arctic sea ice and East Asian Winter Monsoon(EAWM),as well as its variations under global warming,this paper investigated variation features and mechanisms of the relationship between Arctic sea ice concentration and EAWM during the period of 1953-2021 by using slide correlation analysis,linear regression and composite analysis,together with the EAWM north mode and south mode selected to measure the intensity and variation of EAWM.Results detected significant changes of the relationship between Barents Sea's sea ice concentration in November and EAWM north mode from positive correlation during 1962-1977 to negative correlation during 1983-1999 and to insignificant relationship after 2000.With regard to mechanisms of the changes during 1962-1977,when November Barents Sea ice concentration and EAWM showed positive correlation,the anomalous atmospheric circulations in November maintained till winter and caused negative phase of Arctic Oscillation(AO)on Eurasian continent,which strengthened EAWM and transferred the cold dry air from mid-to-high latitude Eurasian mainland to Barents sea at the meantime,thus causing the sea ice concentration to increase.The negative correlation during 1983-1999,on the contrary,was the result of sea ice concentration's impact on EAWM.Sea ice concentration in Barents Sea significantly decreased and further induced negative phase of AO in winter,thus strengthening EAWM by strengthening East Asian trough and East Asian westerly jet.The relationship between Arctic sea ice and EAWM after 2000 was insignificant,during which the relationship between EAWM and AO became more significant.This article investigated changes of the relationship between Arctic sea ice and EAWM,which can help better understand and predict the interannual variation of EAWM.
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