Long-term global GW activity in lower and middle atmosphere from CHAMP, GRACE and COSMIC radio occultation data between 2001 and 2010

LLAMEDO, P.; DE LA TORRE, A.; ALEXANDER, P.; HIERRO, R.; SCHMIDT, T.; HASER, A.; WICKERT, J.

Congreso; AGU Chapman Conference on Atmospheric Gravity Waves and Their Effects on General Circulation and Climate; 2011

We discuss the long-term global tropospheric-stratospheric gravity wave (GW) activity expressed by the specific potential energy derived from GPS radio occultation data, as retrieved by CHAMP, GRACE and COSMIC Low Earth Orbit (LEO) satellites between 2001 and 2010. Systematic annual and interannual features as a function of longitude, latitude and time are shown, extending and/or modifying results and features pointed out in previous climatologies. Possible over/under estimations due to the data processing are also remarked. The GW analysis is based on the correct extraction of the perturbation component of the individual measured temperature profiles by applying different filtering techniques. We test a new filtering procedure that considerably reduces the usually observed wave activity enhancement at the tropopause. After applying a bandpass filter, the perturbation component is detrended again to force a zero mean. For reference, we create known systhetic perturbation components added to background tempertature profiles to compare the ability of the different filtering methods. This filtering procedure considerably reduces a systematic over estimation of the wave activity observed in previous climatologies, mainly at tropopause regions.