On polarimetric radar signatures of deep convection for model evaluation: Columns of specific differential phase observed during MC3E

The representation of deep convection in general circulation models is in part informed by cloud-resolving models (CRMs) that function at higher spatial and temporal resolution; however, recent studies have shown that CRMs often fail at capturing the details of deep convection updrafts. With the goal of providing constraint on CRM simulation of deep convection updrafts, ground-based remote sensing observations are analyzed and statistically correlated for four deep convection events observed during the Midlatitude Continental Convective Clouds Experiment (MC3E). Since positive values of specific differential phase K_DP observed above the melting level are associated with deep convection updraft cells, so-called K_DP columns are analyzed using two scanning polarimetric radars in Oklahoma: the National Weather Service Vance WSR- 88D (KVNX) and the Department of Energy C-band Scanning Atmospheric Radiation Measurement (ARM) Precipitation Radar (C-SAPR). KVNX and C-SAPR K_DP volumes and columns are then statistically correlated with vertical winds retrieved via multi-Doppler wind analysis, lightning flash activity derived from the Oklahoma Lightning Mapping Array, and KVNX differential reflectivity Z_DR. Results indicate strong correlations of K_DP volume above the melting level with updraft mass flux, lightning flash activity, and intense rainfall. Analysis of K_DP columns reveals signatures of changing updraft properties from one storm event to another as well as during event evolution. Comparison of Z_DR to K_DP shows commonalities in information content of each, as well as potential problems with Z_DR associated with observational artifacts.