A Statistical Analysis of Seasonality of Cloud Microphysics, Biogenic Aerosols and Rainfall Over Ocean Using The A-Train Satellites

Abstract:

Aerosols can have a powerful influence on climate through their direct and indirect radiative effects. Indirect radiative effects are based on the way in which aerosols interact and alter cloud optical and microphysical properties. One area of interactions occurs during cloud formation when aerosols act as Cloud Condensation Nuclei (CCN) or Ice Nuclei (IN), and can modify cloud particle/droplet size and number distributions, and hence, influence Earth’s radiation budget. Dominant sources of ocean-derived aerosols that may serve as CCN include sea spray and biogenicly formed aerosol. In this study, we use 10-years of global observations from the A-Train satellites to show seasonal variations of cloud droplet number concentrations, ocean chlorophyll concentrations, distributions of aerosol angstrom parameter and rainfall. Potential cloud-aerosol interactions are explored by considering seasonal and spatial correlations between derived microphysical properties of clouds and aerosols. This study is aimed to better understand the cloud-aerosol interactions over southern ocean and tropical Pacific linked to the ENSO events.