Characteristics of the atmospheric boundary-layer structure and cloud properties for precipitating convection with data assimilation

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Description

The major objective of this study is to create realistic estimates of high-resolution (~1-kilometer horizontal grid size) atmospheric boundary-layer structure and the characteristics of precipitating convection, including updraft and downdraft cumulus mass fluxes and cold pool properties from analyses that assimilate the surface mesonet observations of wind, temperature, and water vapor mixing ratio and available profiling data from single or multiple surface stations. Specifically, data assimilation experiments have been conducted for the major convective cases during the Midlatitude Continental Convective Clouds Experiment (MC3E) using the mesoscale community Weather Research and Forecasting (WRF) model and its data assimilation system. The Oklahoma Mesonet observations and the data obtained from six MC3E sounding stations over the region around the Southern Great Plains (SGP) site have been assimilated. Results show that the data assimilation has resulted in realistic analyses and simulations of the initiation and evolution of precipitating convection. Then, these analyses and simulations obtained from the data assimilation are being used to characterize the convective properties and atmospheric boundary-layer structures associated with precipitating convections. The interaction between convectively generated cold pools and convection as well as the characteristics of vertical velocity statistics in the convective systems are being examined. In addition, the WRF high-resolution analyses are also being compared with the standard ARM large-scale forcing.