资源环境科技发展态势分析平台

This study reveals that the winter East Asian jet stream (EAJS) shows a strong variability in its zonal location; this topic has received less attention compared with the EAJS intensity and meridional location variability in previous studies. We show that the mid-to-high latitude climate system is mainly responsible for the EAJS eastward shift and the tropical system is closely related with the EAJS westward shift. In the EAJS east-located years, North Pacific Oscillation undergoes a positive phase, which can enhance the eastern part of the EAJS over the North Pacific, favouring the eastward shift of the EAJS. In the west-located years, the tropical convection over the Indian Ocean is strong, which can strengthen the zonal angular momentum transport from the Tropics to subtropical westerly belt. Consequently, the western part of the EAJS enhances and the EAJS shifts westward. In addition, the east-located EAJS is related to the intensified Aleutian Low and East Asian trough, and thus, Northeast China, Korean Peninsula, and Japan experience low temperatures. On the other hand, the west-located EAJS is associated with the weakened mid-Asian ridge and cold-temperature advection over southern East Asia, and thus, regions from mid-Asia southeastward to southern China experience cold temperatures. Therefore, the zonal location of the EAJS is a potentially good index of the northern or southern East Asian anomalous temperature pattern.