The Modulation of South Tibetan Plateau Precipitation to the Interdecadal Variations of Summer Eurasia Teleconnection
Based on reanalysis data,present study examines the interdecadal variations of Summer Eur-asia teleconnection(SEAT)from 1958 to 2020 and the modulation of South Tibetan Plateau precipitati-on(STP)to these variations.The results show that SEAT has experienced a significant interdecadal phase shift around 1998,from positive to negative phase.SEAT manifests as a clearly wave train propa-gates from west to east along the subtropical jet,with three anticyclonic anomalous circulation centers over the North Atlantic,the Caspian Sea and the Korean Peninsula and two cyclonic anomalous circula-tion centers located in Central Europe and Mongolia.As the phase shift of SEAT,the circulation pat-terns in above regions have reversed.At the same time,there have been significant anomalies in precipi-tation and temperature on the Eurasian continent.Furthermore,present study finds that there is a sig-nificant correlation between SEAT and STP.On the one hand,the condensation latent heat generated by STP will stimulate Rossby wave trains and then propagate downstream.On the other hand,the re-lease of condensation latent heat will also influence the upward(downward)motion in South Tibetan Plateau,which resulting in divergence(convergence)in the upper air.The vorticity advection anomalies associated with divergence(convergence)will serve as a source of Rossby waves to promote the mainte-nance and propagation of SEAT.Further analysis indicates that changes in the Atlantic Multi-decadal Oscillation(AMO)affect the STP through atmospheric bridge effect,which alters the meridional gradi-ent of tropospheric temperature in South Asia,affecting precipitation in South Asia and the South Tibet-an Plateau,and ultimately modulates the interdecadal variations of SEAT.
万方数据
维普
