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Analysis of Water Vapor Correction for CloudSat W-Band Radar

Josset, D. B., S. Tanelli, Y. Hu, J. Pelon, and P. Zhai (2013), Analysis of Water Vapor Correction for CloudSat W-Band Radar, IEEE Trans. Geosci. Remote Sens., 51, 3812-3825, doi:10.1109/TGRS.2012.2228659.

We analyzed different models to estimate absorption MPM at W-band by gaseous species by taking advantage of the col- ECMWF located CloudSat–Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) measurements. We used the power backscattered by the surface in the green visible wavelength GMAO of the lidar of CALIPSO as a reference to infer CloudSat’s 94-GHz ocean surface backscatter in clear air and infer the attenuation introduced by gaseous absorption. Different millimeter-wave propagation models (MPMs) and different sources to determine GAMSRE the profile of atmospheric thermodynamic state are used to estimate CloudSat attenuation. These estimates are compared to the observations to calculate the residual dispersion. We show here that we need to adjust the empirical constants of preexisting GMODIR water vapor absorption models to minimize the dispersion. Our results indicate an overestimation of absorption by the water vapor continuum at 94 GHz in Liebe-based MPM. We also propose a new empirical model to better represent the absorption of the water vapor continuum near 94 GHz. When this model is used in MPM85 combination with the Advanced Microwave Scanning Radiometer MPM85∗ for the Earth Observing System water vapor path and the Global Millimeter-wave propagation model. European Centre for Medium Range Weather Forecast. Global Modeling and Assimilation Office. In this paper, it relates to the thermodynamical inputs coming from the ancillary meteorological data provided by the GMAO. Acronym used when the GMAO humidity profiles are adjusted to the integrated water vapor path (IWVP) of AMSR-E. Acronym used when the GMAO humidity profiles are adjusted to the IWVP of the MODerate-resolution Imaging Spectroradiometer (MODIS) infrared product. Model of Liebe version of 1985. Model of Liebe “reduced” version of 1985 containing only the main absorption lines. Modeling and Assimilation Office water vapor vertical profile MPM85∗ CO Model of Liebe version of 1985. “Reduced”

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