Deep Convective Transport in Cumulus-Parameterized and Cloud-Resolved WRF-Chem Simulations of an MCS and Storms from Different Convective Regimes during the DC3 Field Campaign

Deep convective transport of surface moisture and pollution from the planetary boundary layer (PBL) to the upper troposphere and lower stratosphere (UTLS) may affect the radiation budget and climate. This study focuses on using a WRF-Chem simulation to analyze the deep convective transport in a mesoscale convective system (MCS) observed during the 2012 Deep Convective Clouds and Chemistry (DC3) field campaign, and comparing its results with those from a multiple supercell case and an air mass thunderstorm case that occurred in the same field campaign. Chemical tracers are used to evaluate the simulated convective transport and storm dynamics. In the fine resolution cloud resolved runs, lightning data assimilation is used to improve the model simulation. The analysis of vertical flux divergence shows that the transport of boundary layer insoluble trace gases is relatively weak in the MCS case. The weak deep convective transport of boundary layer tracers in the strong MCS is unexpected and is caused by the injection into low levels of mid-level clean air by a strong rear inflow jet. Furthermore, in each system, the magnitude of tracer vertical transport is more closely related to the vertical distribution of mass flux density than the vertical distribution of trace gas mixing ratio. In the 12 km and 36 km coarse resolution runs, we tried different cumulus parameterizations, and the GF scheme produces the best result in terms of precipitation. The model simulations are further improved by tuning the closure methods in the GF scheme. The model simulated sub-grid convective transport and redistribution of the trace gases are evaluated by comparing them with the aircraft measurement and cloud resolved runs.