USE OF SATELLITE CLOUD PICTURES TO ESTIMATE AVERAGE RELATIVE HUMIDITY BELOW 500 MB., WITH APPLICATION TO THE GULF OF MEXICO AREA

Abstract

This paper describes a scheme for classifying the cloudiness, as determined from satellite TV pictures, of small areas in the vicinity of radiosonde stations. The classification number, c, was correlated with the observed average relative humidity below 500 mb., H?, at radiosonde stations within a few hundred miles of the Gulf of Mexico and the western Caribbean Sea. For over 100 dates distributed throughout the year the relationship was found to be H? = 24.6 + 7.30 c, with a correlation coefficient of 0.78. There is a slight suggestion of seasonal and latitudinal trends. Examples show suggested average relative humidity distributions based on observations made from meteorological satellites over the waters adjacent to the southeastern United States.