Relationship Between Convective Systems and the Production and Maintenance of Associated Cold Pools

There is a clear importance of understanding the roles of representing convective cold pools, and properly representing those processes in multi-scale meteorological models. In particular, the strong coupling between vertical velocities and surface-based outflows is not well represented in convective parametrization schemes. The main goal of this work is to understand the relationships between the morphological properties of convective systems and the production and maintenance of cold pools using radar-derived microphysical and kinematic observations as well as in-situ and remotely-sensed thermodynamic and kinematic measurements. For this, we take advantage of Oklahoma Mesonet observations, NEXt-generation RADar (NEXRAD) and the Department of Energy-Atmospheric Radiation Measurement (DOE-ARM) and National Aerospace and Space Administration (NASA) radar networks and the vast amount of observations available from the Midlatitude Continental Convective Clouds Experiment (MC3E). In particular, this analysis is centered around deep convective systems and associated cold pools that took place on May 23, 2011. The observational analysis of reflectivity composite from KTLC and KVNX NEXRAD radars and temporal and spatial evolution of surface variables, such as temperature and humidity from both the Oklahoma MESONET and ARM weather stations, led to the satisfactory detection of cold pools for this day. These analyses were co-located with RHI scans from the C-band Scanning ARM Precipitation Radar (C-SAPR), which provided further information of the vertical structure of the cold pool at fine vertical resolution as well as attendant kinematic and hydrometeor evolution cross section plane. The temperature profile evolution from Atmospheric Emitted Radiance Interferometers (AERIs) also provided further information regarding the vertical structure of the cold pool, which agreed in space and time with analyses from the MESONET/ARM weather station analysis.

MC3E observations were also used to characterize the kinematic structures of the observed convective systems (updraft and downdraft properties) and cold pools using traditional multi-Doppler retrievals as well as 3-D variational assimilation approaches. Three-dimensional wind retrievals provided by Mariko Oue and Pavlos Kollias confirmed the vertical structure of the kinematic flows as seen in the C-SAPR’s RHI and provided valuable information of the 3D structure of the cold pool throughout the day. Finally, the potential role(s) of hydrometeor evolution on the evolution of the cold pools, and subsequent feedbacks onto the convective evolution and the formation of new convective updrafts and latent cooling’s impacts on cold pool maintenance are also explored via hydrometeor classification from the KVNX NEXRAD polarimetric datasets.