A Statistical Examination of Nimbus-7 SMMR Data and Remote Sensing of Sea Surface Temperature, Liquid Water Content in the Atmosphere and Surface Wind Speed

Abstract

The Nimbus 7 Scanning Multichannel Microwave Radiometer (SMMR) brightness temperature measurements over the global oceans have been examined with the help of statistical and empirical techniques. Such analyses show that zonal averages of brightness temperature measured by SMMR, over the oceans, on a large scale are primarily influenced by the water vapor in the atmosphere. Liquid water in the clouds and rain, which has a much smaller spatial and temporal scale, contributes substantially to the variability of the SMMR measurements within the latitudinal zones. The surface wind not only increase the surface emissivity but through its interactions with the atmosphere produces correlations, in the SMMR brightness temperature data, that have significant meteorological implications. It is found that a simple meteorological model can explain the general characteristics of these data. With the help of this model, methods are developed for investigation of surface temperature, liquid water content in the atmosphere, and surface wind speed over the global oceans. Monthly mean estimates of the sea surface temperature and surface winds are compared with ship measurements. Estimates of liquid water content in the atmosphere are consistent with earlier satellite measurements.