Validation of GOES Sounder Moisture Profiles: Comparisons with In-situ and Remote Observations

Since April 1994 a new generation of geostationary sounders has been measuring atmospheric radiances in eighteen infrared spectral bands. Retrieved temperature and moisture profiles from these data have been generated in clear skies every hour over much of North America and adjacent oceans since July 1995. This study will focus on validation of these retrievals, as well as the accompanying first guess profiles used to generate the retrievals. First, the standard approach for GOES retrieval validation against the conventional twice-daily, co-located radiosondes will be shown. This approach is less than ideal for several reasons. These include differing instrument measurement characteristics, co-location errors, measurement time differences, and radiosonde errors. An alternative, more comprehensive validation approach will also be examined. This approach uses data from the Department of Energy Atmospheric Radiation Measurement (DOE ARM) program Southern Great Plains Cloud and Radiation Testbed (SGP CART) site central facility, located near Lamont, Oklahoma. Comparisons of GOES retrievals with Cross-Chain Loran Sounding System (CLASS) radiosondes, launched at other than synoptic times, will be shown. In addition, five-minute resolution microwave radiometer (MWR) data is also available at the SGP CART site. These data are considered an accurate, stable reference for total precipitable water (TPW) during non-precipitating periods. In this study, both GOES-8 and -10 retrieved moisture will also be compared to the MWR TPW.