Global Gravity Wave Activities In The Stratosphere Observed By COSMIC Satellites

The global morphologies of potential energy density Ep from stratospheric gravity waves(GWs)are revealed by temperature profiles of COSMIC satellite from January 2007 to February 2013.The connection between Gws and longitudes,latitudes,altitudes and seasons were discussed mainly.Besize,the medium-term variability of GWS in different latitudes was indicated.Finally,the variability of GWs activity was discussed during SSW.In the equatorial region,the activity of GWs are very strong all throughout the year and show clear QBO structure.The large gravity wave Ep values found in tropics between-20° and 20° could be mainly consistent with strong convective regions.In the mid-and high-latitudes,the GWs are strong in winter and weak in summer.In the mid-latitudes,the activities of GWs on continent are stronger than that on the sea in both hemispheres.Meanwhile,the activities of GW in Andes are relatively obvious except summer.In the high-latitudes,the distribution of GW remains stable in southern hemisphere,but in the northern hemisphere,some regions enhance and another weaken.By Lomb-scargle spectra analysis to GW pertur--bation,we found that QBO mainly in low latitude and AO and SAO in the mid-and high-latitude regions.During the period of 2008,2009,2010 and 2013 major SSW events,the Gws activity in polar region enhanced.Just like the enhancement of temperature,the enhancement of Gws progressed downward along with zonal wind.After SSW events,the Gws activity in the polar region weaken.