Long-term observations of gravity wave activity in the lower stratosphere with GPS radio occultation data

94. SCHMIDT, T., FABER, A., DE LA TORRE, A., LLAMEDO, P., ALEXANDER, P. Y WICKERT, J.

Queenstown

Conferencia; SPARC; 2014

Global gravity wave (GW) parameters (potential energy and vertical flux of absolutehorizontal momentum) are retrieved from GPS radio occultation (RO) data.The RO technique uses GPS signals received aboard low Earth orbiting satellites foratmospheric limb sounding. Atmospheric temperature profiles are derived with high verticalresolution. The GPS RO technique is sensitive to GWs with small ratios of vertical tohorizontal wavelengths.Since 2006 the six-satellite U.S./Taiwan FORMOSAT-3/COSMIC mission delivers about2000 global distributed radio occultations daily. This gives the possibility for thedetermination of the absolute momentum flux (MF) as an important parameter for thequantification of GW influence to the atmospheric circulation.In this presentation we discuss MF distributions in the lower stratosphere derived fromtriples of spatio-temporal nearby temperature fluctuation profiles for different seasons. Theresults are compared with other MF climatologies. Possibilities and limitations of themethod will be addressed. In addition to the MF results long-term climatologies and trendsof the potential energy and vertical wavelengths derived from several RO missions since2001 will be presented.