The Eurasian Jet Streams as Conduits for East Asian Monsoon Variability

Abstract

This article gives a brief review on how the jet streams over the Eurasian continent influence the East Asian monsoon on intraseasonal to interdecadal time scales and discusses the seasonal predictability and change. The wave train along the Eurasian jet streams is found to be crucial for East Asian monsoon variability. Interaction of the upper-level Rossby wave train with the Siberian High causes changes in winter monsoon climate over East Asia. In the case of summer, the Silk Road pattern, embedded in the Asian jet in association with western North Pacific circulation and the Pacific-Japan pattern, alters the strength and phase of the monsoon. Current coupled models showed limited skills in seasonal prediction of the Eurasian jet variations and their influences on the East Asian monsoon variability. The Eurasian jets as conduits for East Asian monsoon variability involve multiple feedbacks. Its interaction with low-level circulation mostly determines the degree of strength of variations in the monsoon climate. Global warming projections based on RCP 4.5 and 8.5 in the CMIP5 (the Coupled Model Intercomparison Project phase 5) models indicate that the mean Asian jet strengthens in future during winter, but no change is reported during summer.