Abstract:
Using the monthly data of sea ice concentration,precipitation,sea surface temperature,500 hPa geopotential height,and 850 hPa wind field under RCP8.5 scenario of MPI-ESM-LR model,a comparative analysis of the difference of relationship between spring Arctic sea ice and East Asian summer precipitation before and after Arctic sea ice abrupt change and explore its possible causes.The results show that 1)The abrupt change of Arctic sea ice has caused changes in the Arctic Sea Ice Concentration (SIC) and ENSO's influence on East Asian summer precipitation.Before the abrupt change,SIC and ENSO jointly affect the interannual variation of precipitation;after the abrupt change,ENSO dominates the EOF's first mode of precipitation,and SIC dominates the EOF's second mode of precipitation;2)Before the abrupt change of Arctic sea ice,ENSO and SIC affected the 850 hPa wind field in the whole east Asia through the 500 hPa meridional wave train,and eventually leading to a tripole-type precipitation mode.After the sudden change,ENSO affects the 850 hPa wind field in South China through the 500 hPa meridional wave train,leading to the dipole spatial mode of rainfall,which dominates the EOF's first mode of precipitation;Meanwhile,SIC influences the wind field of 850 hPa in the north through the 500 hPa zonal wave train in east Asia and finally dominates the EOF's second mode of precipitation.3)Rapid change in Arctic sea ice,the regional differences of East Asia observed from the effects of ENSO and SIC on summer precipitation.Before the abrupt change of Arctic sea ice,ENSO and SIC jointly affected rainfall in North and South China;after the abrupt change of Arctic sea ice,SIC mainly affected precipitation in North China,and ENSO mainly affected rainfall in South China.