Seasonal analysis of gravity waves over the southern Andes and the Antarctic Peninsula by means of GPS radio occultations

D. LUNA; P. ALEXANDER; A. DE LA TORRE; P. LLAMEDO; T. SCHMIDT; J. WICKERT

Bologna

Congreso; Sparc; 2008

The Global Positioning System (GPS) Radio Occultation (RO) technique has global coverage and is capable of generating high vertical resolution temperature profiles of the troposphere and lower stratosphere with sub-Kelvin accuracy and long-term stability, regardless of weather conditions. Fluctuations in these profiles give information about gravity wave potential energy per unit mass (Ep).  This study employed 6261 temperature profiles obtained by the CHAMP (CHAllenging Minisatellite Payload) and SAC-C (Satélite de Aplicaciones Científicas-C)  missions over the years 2002-2005. An analysis of monthly averages of Ep showed enhancements during September and October in the wave activity over the whole area. Some of the most energetic RO events were detected over zones where the topography is expected to play an important role, however intense RO events were also found over the ocean too.According to the morphology of the mountains in the studied region, near-meridional alignment of the line of sight (LOS), would improve the detection of mountain waves. Nevertheless, no predominant orientation for the LOS was found for RO with high Ep values.