第一届未来大气科学论坛

Using observations, reanalysis data sets, a linear barotropic model, and a state-of-art chemistry-climate model, we investigated the influence of Arctic stratospheric polar vortex (SPV) and ozone variabilities on surface air temperature (SAT) and precipitation in Asia. An out‐of‐phase interannual linkage between the SPV in December‐January and SAT in February during 1979–2022 has been observed, that is, a strong (weak) SPV corresponds to a cooling (warming) over Asia. This relationship is independent of the Arctic Oscillation. The influence of the SPV on SAT over Asia cannot be solely explained by radiative processes, but is instead related to circulation anomalies in the troposphere. Specifically, the influence of the SPV on Asian SAT is mediated through the "downward control" mechanism. A strong SPV signal propagates downward to the Atlantic sector, weakening the Northeast Atlantic-East Europe-Asia tripolar teleconnection wave train. This weakens planetary wave propagation from the North Atlantic to Asia, leading to negative geopotential height anomalies and cyclonic circulation anomalies over the region. These circulation anomalies, accompanied by anomalous northerly winds, are beneficial to the colder air transportation from the higher latitudes to Asia, facilitating a surface cooling over Asia. We also found the robust influences of March Arctic stratospheric ozone (ASO) on the differences in the precipitation and evaporation in April over Eastern China. When ASO decreases in March, it tends to result in a higher and colder tropopause in the polar, a stronger subtropical jet stream, an intensified local Hadley circulation accompanied by anomalous downward motion over Eastern China, and consequently, drying in this region, and vice versa. These findings suggest that Arctic stratospheric variability could serve as potential predictors for temperature and precipitation changes in East Asia.
 

平流层极涡，臭氧，温度