Collocation over the same cloud element is very difficult as the satellite sensors have different FOVs, viewing times, and viewing angles. This is caused primarily by the larger noise in the VAS sensor which inhibits CO2 slicing solutions for smaller cloudy versus clear radiance contrasts and identifies the cloud as low opaque in the infrared window solution. The geographical distribution of the probabilities of high clouds above 500 hPa in each season computed from VAS and HIRS are presented in Figure C1. The cloud cover patterns are similar. The geographical distribution of cloud reports from HIRS is similar to that from VAS, especially when a small VAS view angle is maintained.
T refers to the corresponding infrared optical depth.
T refers to the corresponding infrared optical depth. T refers to the corresponding infrared optical depth. T refers to the corresponding infrared optical depth. Back to the main text of the paper.