Satellite Observed Sensitivity of Tropical Clouds and Moisture to Sea Surface Temperature on Various Time and Space Scales. Part I: Focus on High Level Cloud Situations over Ocean

This study examines variations in high cloud properties and relative humidity (RH) with sea surface temperature (SST) over tropical oceans (30°N–30°S) using spaceborne lidar microwave radiometer observations. The mean values the tropics indicate that middle-tropospheric RH increases, covers decrease altitudes rise SST. These signatures are consistent hypotheses proposed literature. analysis of this same data set but at scale local processes shows different behaviors for SSTs <302 K >302 K. Between 299 302 K, RH, opaque cover, top altitude increase together SST, while optically thin cover decreases. Over clouds increases. Interestingly, (not top) increases monotonically SST from to 305 on a range space time scales, remains higher than clouds. observed relationships scales compared simulations global atmospheric model. Despite systematic biases, model reproduces sensitivity rather well fails reproduce balance between cover.