摘要
The profound impact of solar irradiance variations on the decadal variability of Earth’s climate has been investigated by previous studies.However,it remains a challenge to quantify the energetic particle precipitation(EPP)influence on the surface climate,which is an emerging research topic.The solar wind is a source of magnetospheric EPP,and the total energy input from the solar wind into Earth’s magnetosphere(Ein)shows remarkable interdecadal and interannual variability.B ased on the new Ein index,this study reveals a significant interannual relationship between the annual mean Einand Eurasian cold extremes in the subsequent winter.Less frequent cold events are observed over Eurasia(primarily north of 50°N)following the higher-than-normal Ein activity in the previous year,accompanied by more frequent cold events over northern Africa,and vice versa.This response pattern shows great resemblance to the first empirical orthogonal function of the variability of cold extremes over Eurasia,with a spatial correlation coefficient of 0.79.The pronounced intensification of the positive North Atlantic Oscillation events and poleward shift of the North Atlantic storm track associated with the anomalously higher Ein favor the anomalous extreme atmospheric circulation events,and thus less frequent extreme cold temperatures over northern Eurasia on the interannual time scale.It is further hypothesized that the wave-mean flow interaction in the stratosphere and troposphere is favorable for the connection of Ein signals to tropospheric circulation and climate in the following winter.
基金
supported by the National Key R&D Program of China(Grant No.2016YFA0600703)
the National Natural Science Foundation of China(Grant Nos.41875118,41605059 and 41505073)
the Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.KYCX18_0997)
the funding of the Jiangsu Innovation&Entrepreneurship Team
the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions
supported by the International Space Science Institute(ISSI)in Beijing,through the working team“Dynamical signatures of energetic particle precipitation in atmospheric re-analyses”(ID:32,2019)。
