A study of clouds using satellite radiance data in comparison with raingage network and radar observations

Date

1980-06

Journal Title

Journal ISSN

Volume Title

Publisher

Texas Tech University

Abstract

The objective of this study was to use Geostationary Operational Environmental Satellite (GOES) visible and infrared radiance data to determine cloud characteristics, including cloud population, albedo, cloud top temperature and height, as well as the changes of cloud parameters with time. Verification of the satellite-derived results was achieved by comparison with the corresponding raingage network measurements and observations by radar.
Four cases, 22, 24 and 27 June and 8 July 1977, have been chosen for this study. All four occurred during the operational period of the 1977 Texas HIPLEX (High Plains Cooperative Program) field season when visible and infrared images and digital radiance data, surface and rawinsonde data, precipitation analyses from the raingage network as well as PPI and RHI radar displays were available. In the first portion of this study, visible radiance data were used to determine cloud populations, percent cloud cover and cloud albedos, while cloud top temperatures were computed from the infrared data. Cloud top heights have been determined by using the cloud top temperature and comparing with rawinsonde data obtained from the nearest station. The second portion of the study compared the results derived from satellite data with raingage network measurements and radar observations in the Texas HIPLEX area. The analysis indicated that the information derived from satellite, radar and raingage data correlated closely on the four case study days. The precipitation analyses indicated that two of the four case study days had heavy rain but the others had little or none. Synoptic, subsynoptic, and small-scale features were investigated to determine the mechanisms of precipitation. PPI radar displays from a WSR-57 radar at Midland and both digital PPI and RHI data from a M-33 radar at Snyder were used in this investigation. On 22 June a squall line, a subsynoptic feature, and on 8 July a cold front, a synoptic feature, triggered the development of a line of convective clouds which produced the observed precipitation.

Description

Keywords

Cloud forecasting, Meteorological satellites, Rain gauges, Clouds, Radar meteorology

Citation