Mountain waves above the southern andes, drake passage and antarctic peninsula

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

Bremen, Alemanaia

Congreso; 38th COSPAR Scientific Assambly 2010; 2010

COSPAR

From satellite data, it was observed that this region is one of the most energetic on Earth for the vertical propagation of gravity waves (GWs). The Drake Passage is one of the stormiest places on earth, and thus also a signicant source of large amplitude GWs from other mechanisms than topographic forcing. From GPS radio occultation proles, WRFV3 mesoscale model simulations initialized by ECMWF and wavelet analysis, we study the main stationary modes usually present in this area. In particular, we describe the systematic propagation of up to three large amplitude GW stationary modes generated by the mountain forcing of the strong eastward winds. Wavelet analyses at constant pressure levels reveal that these modes exhibit a prevailing eastward component and horizontal wavelengths between tens and hundred kilometers. They are described as a function of latitude, longitude, height and season. Their amplitudes, vertical and horizontal wavelengths and directions of propagation are described.