Contrasting characteristics of continental and oceanic deep convective systems at different life stages from CloudSat observations

Abstract

The deep convective system (DCS) has large impacts on the radiation balance, global circulation and consequent the climate change. However, a reasonable representation of the DCS characterization in numerical models is limited by the understanding of its evolutionary mechanism. In this study, we investigate the land-ocean DCS contrast using three years (2015–2017) of cloud profiling radar (CPR) observations from the CloudSat satellite based on a connected area DCS identification approach. We identify the DCS life stages through a buoyancy determination, and conduct a composite image method to provide robust internal statistical structure of the morphology, radar reflectivity and microphysical properties of oceanic and continental DCS during each life stage. Reasonable evolutionary mechanisms of DCSs over ocean and land is proposed. It is found that the continental DCS height is strongly influenced by the intense of convection, and its volume decrease when heavy precipitation occurs. While the oceanic DCS can maintain a larger volume due to the sufficient water vapor supply. It often presents with dispersed stratified precipitation and the main procedure of its dissipation is the cloud edge entrainment. Our results may provide a pathway to evaluate the life cycle and evolution mechanism of DCS from model simulation.