An approximate but accurate method of stereo-height computations from overlapping images of geosynchronous satellites is presented. The method was applied to determine the height of ITCZ clouds from GMS-1 and GOES West images. The cloud-top topography of severe thunderstorms over the United States was obtained from GOES East and West images along with IR temperature measurements by both satellites. It was found that the IR temperature is 5 to l0° warmer than the expected temperature of overshooting tops.
It is suspected that the warm IR temperature is caused by the stratospheric cirrus located 1 to 3km above the anvil top, which was found repeatedly during the Lear Jet Experiment in 1971-1978. The cirrus is generated in the wake of overshooting tops as they sink violently into the anvil cloud. The radiometric characteristics of the cirrus uncouple the heighttemperature relationship at the overshooting height, resulting in an uncertainty that the cloud-top warming may mean either sinking cloud top and/or increasing cirrus.