https://phys.org/news/2018-05-positive-feedback-east-asian-mid-latitude.html

"We found a close relationship between the surface air temperature in the Russian Far East and the northern flank of the EAJ and revealed a positive feedback mechanism between them," she said.

LIN's study indicated that related to a warmer surface in the Russian Far East, the westerly decelerates in the northern flank of the EAJ. The anticyclonic circulation anomaly related to a weakened westerly in the northern flank of the EAJ induced surface warming in the Russian Far East and the warmer surface could in turn act as a heat source and induce a local anticyclonic circulation anomaly in the upper troposphere, therefore decelerating the westerly in the northern flank of the EAJ.