Summary: Absolute values of gravity wave momentum flux
derived from satellite data
Manfred Ern and Peter Preusse
Institute for Chemistry and Dynamics of the Geosphere I, Forschungszentrum Jušlich, Jušlich, Germany
M. Joan Alexander
Colorado Research Associates, Boulder, Colorado, USA
Christopher D. Warner
Centre for Atmospheric Sciences, University of Cambridge, Cambridge, UK
Received 10 March 2004; revised 18 June 2004; accepted 20 July 2004; published 19 October 2004.
 Temperature data obtained by the Cryogenic Infrared Spectrometers and Telescopes
for the Atmosphere (CRISTA) are analyzed for gravity waves (GWs). Amplitude,
phase and vertical wavelength are determined from detrended temperature height profiles.
The retrieved phases are utilized to estimate the horizontal wavelengths. At 25 km altitude
an equatorial maximum of horizontal wavelength with a decrease toward mid and high
latitudes is found. Simultaneous estimates of both horizontal and vertical wavelengths and
temperature amplitudes allow the direct calculation of GW momentum flux (MF) from
satellite observations for the first time. However, histograms of horizontal wavelength
distributions indicate severe undersampling which prevents the retrieval of the
propagation directions of the waves, and suggests our MF estimates may be too low,
particularly at the high latitudes. Therefore an empirical aliasing correction has been applied.