A new approach to global gravity wave momentum flux determination from GPS radio occultation data

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

Atmospheric Measurement Techniques D

Copernicus

Lugar: Amsterdam; Año: 2013 vol. 6 p. 2907 - 2933

1867-8610

GPS Radio Occultation (RO) is a well-established technique for obtaining global gravity wave (GW) information. RO uses GPS signals received aboard low Earth orbiting satellites for atmospheric limb sounding. Temperature profiles are derived with high vertical resolution and provide a global coverage under any weather conditions offering the possibility for global monitoring of the vertical temperature structure and atmospheric wave parameters. The six satellites constellation COSMIC/FORMOSAT-3 delivers approximately 2000 temperature profiles daily. In this study, we use a method to obtain global distributions of horizontal gravity wave wavelengths, to be applied in the determination of the vertical flux of horizontal momentum transported by gravity waves. The horizontal wavenumber is derived by the ratio of the phase shift and the spatial distance between adjacent temperature fluctuation profiles at a given altitude, following the method by Ern et al. (2004). A new method for the determination of the real horizontal wavelength from triads of vertical profiles is presented and applied to the COSMIC data. The horizontal and vertical wavelength, the specific potential energy (Ep) and the vertical flux of horizontal momentum (MF) are calculated and their global distribution is discussed.