Observed dynamic and radiative characteristics of tropical deep convective and anvil clouds for different UT stabilities

This study aims to investigate the control of upper tropospheric (UT) stability characterizing deep convective clouds over the tropical oceans from CloudSat and CALIPSO observations. To this end, the vertical structure of convective systems is examined with focus on deep convective cores and anvil clouds classified by a cluster-analysis method developed previously. The UT stability is decomposed into four classes, from the most unstable to the most stable. Different UT stabilities are found to have systematic variability in convective dynamic structure. The highly unstable UT as found over the West Pacific ITCZ exhibits very strong vertical motion, accompanied by very deep convective clouds and extensive anvil clouds. As the UT becomes more stable, as is typical of the East Pacific ITCZ, the deep convective cloud tops shift to a slightly lower level, and the anvil cloud fraction is found to be lower. The all-sky radiative effect remains cooling even with the anvil cloud heating, except for the most unstable UT, where the cloud radiative heating overwhelms the gaseous cooling. As such, the anvil radiative effects change even in sign depending on UT stability.