Observation of the two-day wave near the southern summer stratopause

Temperature and H2O measurements from the Upper Atmospheric Research Satellite Microwave Limb Sounder (UARS MLS) data sets during southern hemisphere summer of 1991–92 are analyzed using the asynoptic mapping method. Results show a prominent wavenumber 3 two-day wave confined to latitudes between 60°S and 4°N and to altitudes above 2 hPa. The temperature wave amplitude increases upward to the upper limit of the observations and maximizes at 2.0 K near 0.465 hPa. The H2O wave amplitude reaches a maximum of 0.25 ppmv near 1 hPa. Evidence suggestive of wave breaking and meridional mixing associated with the interaction between this wave and a lower frequency wavenumber 1 is shown.