Weakening of Antarctic stratospheric planetary wave activities in early austral spring since the early 2000s: a response to sea surface temperature trends

Abstract. Using multiple reanalysis datasets and modeling simulations, the trends of Antarctic stratospheric planetary wave activities in early austral spring since 2000s are investigated this study. We find that September have weakened significantly year 2000, which is mainly related to weakening tropospheric sources extratropical Southern Hemisphere. As ozone also shows clear shift around impact recovery on activity examined through numerical simulations. Significant lower stratosphere changes atmospheric state for propagation some extent, inducing a slight decrease vertical flux upper troposphere (UTLS). However, environment middle over subpolar region not significant. The has minor contribution significant September. Further analysis indicates trend sea surface temperature (SST) 20∘ N–70∘ S well linked activities. model simulations reveal SST Hemisphere (20–70∘ S) tropics (20–20∘ induce 1 component geopotential height Hemisphere, subsequently leads flux. In addition, both data indicate Brewer–Dobson circulation (BDC) been 2000 due