Abstract
The Antarctic stratospheric sudden warming (SSW) occurred on August 30,
2019, and was a vortex displacement minor warming event. We investigated
variations in gravity waves (GWs) before and after this rare Antarctic
SSW event using two satellite measurements (AIRS and CIPS) and
reanalysis data (GEOS-5 FP). The observations showed that the GW
activities decreased after the SSW onset, with a weakening of zonal
wind. The decrease in GW activity coincided with a reversal of the zonal
wind around September 8 in GEOS-5 FP. The temporal variation of GWs was
similar to that of Arctic GWs during vertex displacement minor SSWs. The
decline in GW activities was probably caused by wind filtering and polar
night jet breaking. However, the GW activities over the Andes and the
Antarctic peninsula decreased at the onset, although the westly wind was
40–60 ms-1. This decrease could have been caused by
wave saturation.