The Boreal Summer Rainfall Changes in Eastern China and Associated Spatial Heterogeneous Jets Variations During the Arctic Amplification Period

Abstract

Arctic surface temperature rising has been three times faster than the globe, referred to as the Arctic amplification (AA). However, the changes of boreal summer rainfall in eastern China and associated physical mechanisms during the AA period are still under investigation. In this study, we explored the boreal summer meridional quadrupolar rainfall changes in eastern China during the AA period, distributed as positive-negative-positive-negative anomaly pattern form north to south in eastern China. This pattern is significantly linked with the heterogeneous variations of the polar front jet (PJ) and subtropical jet (SJ), as the PJ displaced poleward over the Eurasia and the SJ displaced equatorward from the North Atlantic to East Asia. Such movement of different branches of jets are referred as the wavier jets that can be maintained by the negative phase of East Atlantic-Europe Pacific teleconnection (−EAUP), which might be associated with the positive phase of the Victoria mode over the North Pacific, the tripole sea surface temperature mode over the North Atlantic, and the reduction of sea ice concentration over Arctic. This study has emphasized the role of the heterogeneous variations of PJ and SJ playing on boreal summer quadrupolar rainfall changes in eastern China during the AA period.