Interactions between Cumulus Convection and Its Environment Revealed by MC3E Sounding Array

Description

After decades of efforts, accurately representing cumulus convection is still one of the most challenging tasks in weather and climate models. This is primarily because the interaction between cumulus convection and its environment has not been fully understood. The interactions between cumulus convection and its environment can be examined by analyzing the large-scale budgets of temperature and moisture using the sounding data collected from major field campaigns. Previous budget diagnostic studies have been mostly on tropical convective systems given the dominant role that they play in the global water cycle. Only a few studies have been carried out in the midlatitudes with the data collected decades ago. Using the data collected by the recent MC3E field campaign, this study computes the large-scale budgets of temperature and moisture through the constrained variational objective analysis. Typical midlatitude continental convective systems that often occur in the central United States, including well-organized squall lines and scattered storms, were observed during MC3E. The focus here is to elucidate the variations in large-scale conditions as well as diabatic heating and drying structures in these convective cloud systems. The goal is to understand how the large-scale atmospheric structure interacts with the organization of the MC3E convective systems. Impacts of uncertainties in surface precipitation on the derived heat and moisture budgets as well as how they vary with different analysis domain sizes are also discussed. This work is performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.