Skip to Main content Skip to Navigation
Theses

Inversion des mesures radiométriques haute-fréquence au-dessus des surfaces continentales

Abstract : The main objective of this thesis is to study the potential and the feasibility of atmospheric temperature and humidity profile retrievals over land using microwave sounding measurements and especially AMSUA and-B ones. Indeed, microwave measurements are assimilated over oceans in many meteorological centres but remain insufficiently exploited over land. The land emissivity is high (almost close to 1.0) and is highly variable with surface characteristics. Consequently, it is difficult to separate the relative contributions of the surface and the atmosphere to the measured radiances. An important part of this work has been dedicated to the land emissivity estimation at AMSU frequencies (23-150 GHz) and scanning conditions (from -58° to +58° with respect to nadir). The land emissivity calculations have been conducted over the globe and using cloud free data from year 2000. The land AMSU emissivities have been evaluated by examining their angular and spectral dependences and by comparison to SSM/I emissivities. Theses analyses permit the development of a microwave land emissivity parameterization for frequencies ranging from 23 to 150 GHz and scanning angles up to 58°. Thereafter and with a good knowledge of the surface (emissivity and skin temperature), the feasibility of the AMSU temperature and humidity profiles has been studied by conducting an information content analysis. This study shows that AMSU measurements when combined with a reliable surface emissivity and skin temperature could produce valuable estimations of the atmospheric temperature and humidity profiles especially at atmospheric low levels.
Document type :
Theses
Complete list of metadata

Cited literature [103 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-00524882
Contributor : Fatima Karbou Connect in order to contact the contributor
Submitted on : Saturday, October 9, 2010 - 11:36:33 AM
Last modification on : Wednesday, October 20, 2021 - 12:24:08 AM
Long-term archiving on: : Thursday, October 25, 2012 - 4:46:44 PM

Identifiers

  • HAL Id : tel-00524882, version 1

Collections

INSU | CNRS | CETP | UVSQ

Citation

Fatima Karbou. Inversion des mesures radiométriques haute-fréquence au-dessus des surfaces continentales. Planète et Univers [physics]. Université de Versailles-Saint Quentin en Yvelines, 2004. Français. ⟨tel-00524882⟩

Share

Metrics

Record views

134

Files downloads

236