Precipitation susceptibility estimate in warm marine clouds using multi-sensor aerosol and cloud products from A-Train satellites

Description

Quantifying precipitation susceptibility to aerosols is important for understanding aerosol-cloud interactions and for further constraining aerosol indirect effects. However, it has been challenging to derive precipitation susceptibility from different data sets and different studies have shown large discrepancy. In this study, multi-sensor aerosol and cloud products from satellite observations, including those from CALIPSO, CloudSat, MODIS and AMSRE from June, 2006 to December, 2013, are analyzed to estimate the precipitation susceptibility in warm marine clouds, and results are further compared with estimates from in situ observations. Our results show that precipitation susceptibility calculated with respect to cloud droplet number concentrations (CDNC) is much larger than that calculated with respect to aerosol index (AI) from satellite observations, due to the weak dependency of CDNC on AI. Precipitation intensity susceptibility (SI) to aerosols in satellite observations is shown to be sensitive to different cloud water products while precipitation frequency susceptibility (SPOP) estimated from a different data set is similar. Our results further showed that precipitation susceptibility strongly depends on atmospheric stability, which is a robust feature across different aerosol and cloud data sets. Comparison with in situ observations from the VOCALS-Rx field campaign and over the ARM Azores site helps to further quantify the uncertainty in satellite observations.