Sensitivity study on scale dependence of WRF–Chem simulations of marine stratocumulus observed during VOCALS-REx

This study focuses on gaining an understanding of how interactions between aerosols and clouds impact marine stratocumulus clouds, as well as how model resolved scales affect the simulated clouds and aerosol characteristics in WRF-Chem (the chemistry version of the Weather Research and Forecasting model). The WRF-Chem (V3.2) simulations are conducted using both mesoscale (15 km) and cloud system-resolving scales (3 km) with fully coupled aerosol-cloud-interaction modules. With focus on pockets of open cells (POCs) and closed cells, the simulations are evaluated against observations of cloud structures, cloud microphysics, cloud optical properties, and aerosol characteristics. The evaluation uses extensive in-situ and remotely sensed data from a variety of platforms deployed during the VOCALS-REx (VAMOS Ocean-Cloud-Atmosphere-Land Study Regional Experiment). We anticipate gaining a detailed understanding of the physiochemical processes that drive the life cycle of POCs, and gaining some insight on the scale dependence of WRF-Chem in simulating the POCs over the Southeast Pacific.