Simulations of aerosol, cloud, and precipitation effects in comparison with ARM data

Description

The objectives of our proposal are to evaluate the capabilities of the CAM5 model to capture aerosol-cloud-precipitation interactions, to identify weaknesses, and to ascertain possible improvements. This study will be carried out through a combination of cloud system resolving model (CSRM) studies, studies with CAM5 and the CAM5 single column model (SCM), and comparison of both with ARM measurements. Here, we carry out simulations with a CSRM model for large and small aerosol burdens. We compare these with ARM data to test the response of the CSRM low-level clouds to increases in aerosols. We choose situations where the large-scale forcing, as determined with the ARM RUC data are similar, so that most of the response of the clouds is caused by the change in aerosol burden. Our plan is to also simulate these situations using the CAM5 single column model and then to degrade the CSRM physics in order to understand the causes of any differences.