As strong cooling agents in the climate system, marine low-level clouds are an important component of the climate system. Demonstrating how marine low-level clouds respond to anomalies in the atmospheric general circulation in the present climate has the potential to be illustrative of how low clouds might change in a future climate. We examine how thermodynamic factors that control low cloud occurrence change during an ENSO cycle and then how low clouds observed by the CloudSat and CALIPSO satellites vary. In addition to the well-known decrease in marine low clouds in the Northeast Pacific during El Niño onset in June, July and August (JJA), we also find significant increases in the low cloud occurrence on the flanks of the anomalously warm water in the Equatorial Central Pacific during December, January and February (DJF). These low cloud changes are linked to measurable changes in the Earth’s energy budget with net warming of the Earth system during JJA and cooling of the Earth system during DJF.
This is the python code to create the figures for the paper about the above research.
