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The GIFTS team has pioneered the algorithms for routine extractions of
temperature and moisture profiles from polar and geostationary
satellite spectral radiances. The concept of improving vertical
sounding resolution by observing a large number of spectral channels
(i.e., spectra) with high spectral resolution is the scientific basis
for the EOS-PM Atmospheric Infrared Radiation Sounder AIRS, the NPOESS
Cross-track Interferometer Sounder (CrIS), and the Advanced
Geosynchronous Sounder (AGS). The spectral radiance to temperature
and moisture profile inversion has been studied extensively. Researchers at University of Wisconsin - Cooperative Institute for Meteorological Satellite Studies (UW-CIMSS) have pioneered the process of tracking discontinuities in radiance fields (images) over predefined time intervals to infer atmospheric motion. Wind extraction algorithms have been operationally implemented by NOAA. These algorithms are fully automated and calculate vector displacements from cloud and water vapor motions in sequential satellite imagery at high spatial resolution. The GOES contains three quasi-independent water vapor absorption bands employed collectively to produce water vapor wind vectors which represent the upper-tropospheric flow (200-500 Mb) in cloud-free regions. The complementary nature of the vectors derived from each individual spectral band allows for a spatially coherent wind field that can benefit both qualitative analysis and data assimilation. However, due to the small number (3) and relatively broad weighting functions associated with these channels, the vector height assignment is ambiguous and is the major limitation in the use of these wind data. In spite of height assignment limitations, the GOES wind vectors have proven useful to subjective analyses of storm events. In addition, the quantitative information has resulted in positive impacts on numerical forecasts. However, improved assimilation strategies and parameterizations are constantly emerging, placing increasing demands on observation quality. An advanced profile sensing capability, such as GIFTS, is a necessary step for improved observations of the initial atmospheric state as needed for improved forecasts. |