Parameterization of internal gravity waves and turbulence in the stratosphere using scintillation measurements by GOMOS on Envisat
Viktoria Sofieva(1), Alexandre S. Gurvich(2), Francis Dalaudier(3) and Valery Kan(4)
(1) Finnish Meteorological Istitute, P.O. Box 503, 00101 Helsinki, Finland
(2) A.M. Oboukhov Institute of Atmospheric Physics, Pyzhevsky 3, 119017 Moscow, Russian Federation
(3) Service d'Aeronomie du CNRS, BP 3, 91371 VERRIERES-LE-BUISSON CEDEX, France
(4) A.M. Oboukhov Institute of Atmospheric Physics, Pyzhevsky 3, 119017 Moscow, Russian Federation
The upward propagating waves and their breaking into turbulence are of fundamental importance for the dynamics and mixing within the middle atmosphere. Exploitation of stellar scintillation is a new approach that allows studying air density irregularities in the stratosphere.
In this work, we present algorithms for reconstruction of IGW (internal gravity waves) and turbulence parameters using scintillation measurements by the GOMOS (Global Ozone Monitoring by Occultation of Star) fast photometers on board the Envisat satellite.
The forward model is based on two-component spectral model of air density irregularities: one of the components is generated by locally isotropic turbulence, the second, anisotropic one, is a consequence of the internal gravity waves activity.
The retrieval of parameters of IGW and turbulence spectra - structure characteristics, inner and outer scale of the anisotropic spectrum – is based on the maximum likelihood method.
The developed algorithms are tested on simulated and real data. It is shown that the measured scintillation spectra are in good agreement with the proposed model. It is demonstrated that structure characteristics, inner and outer scales on the IGW component can be reconstructed from scintillation spectra at altitudes above 25 km. The reconstructed parameters are in good agreement with previous analyses.
Further analysis of the GOMOS scintillation data will give information about global distribution of IGW and turbulence parameters in the stratosphere.
Keywords: ESA European
Space Agency - Agence spatiale europeenne,
observation de la terre, earth observation,
satellite remote sensing,
teledetection, geophysique, altimetrie, radar,
chimique atmospherique, geophysics, altimetry, radar,