Morphology of the Lower Stratospheric Gravity Wave Activity

In this study we investigated the gravity wave activity in the lower stratosphere during a 12-year period from 2002 to 2013. Using the temperature profiles observed by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument onboard the Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics (TIMED) satellite, we retrieved the temperature perturbations and evaluated the potential energy Ep which is corresponding to the gravity wave activity. The values of Ep were related to the topographic distribution especially mountain ranges, and larger over continents than oceans. The monthly mean values of Ep showed a quasi-biannual variation which is correlated to the zonal wind filed in the equatorial region, and an annual variation at mid-and high-latitudes. The climatological behaviors of Ep were compared with deep convections in the tropical region, and more evidence showed that the gravity wave activity was affected not only by convective activities but also other large-scale meteorological systems in mid-latitudes.