Convective Transport of Aerosols at Hydrostatic and Non-Hydrostatic Scales using the Model for Prediction Across Scales

Using uniform- and variable-resolution meshes with the Model for Prediction Across Scales (MPAS) allows us to contrast the impact of parameterized versus explicit convective transport of aerosols on aerosols-clouds-precipitation processes in a global framework. We recently added the aerosol-aware option of the Thompson cloud microphysics scheme and convective transport of those aerosols in the scale-aware Grell-Freitas parameterization of deep convection available in MPAS. At present, "water-friendly" and "ice-friendly" aerosols are simply entrained in subgrid- scale convective updrafts and downdrafts, and detrained at cloud-tops, but without influencing condensation in convective plumes. We hypothesize that including the convective transport of aerosols will help improve vertical profiles of the cloud liquid and ice water content in convective clouds and precipitation compared to those without convective transport at hydrostatic scales. We expect that including subgrid-scale convective transport will help reduce biases compared to forecasts at convection permitting scales.

We present results of 3-day forecasts of the 11^th June 2012 mesoscale convective system that was observed during the Deep Convective Clouds and Chemistry (DC3) field campaign. We run our forecasts with a 15 km uniform-resolution mesh and a 15-3 km variable-resolution mesh with mesh refinement centered of the Continental United States. Results focus on the impact of parameterized versus explicit convective transport of cloud condensation nuclei on the lifecycle of the mesoscale convective system and surface precipitation. Limited comparisons against DC3 measurements will be discussed.