Retrievals of Convective Detrainment Heights Using Ground-Based Radar Observations

To better constrain model simulations, more observations of convective detrainment heights are needed. For the first time, ground-based S band radar observations are utilized to create a comprehensive view of irreversible convective transport over a 7-year period for the months of May and July across the United States. The radar observations are coupled with a volumetric radar echo classification scheme and a methodology that uses the convective anvil as proxy for convective detrainment to determine the level of maximum detrainment (LMD) for deep moist convection. The LMD height retrievals are subset by month (i.e., May and July), by morphology (i.e., mesoscale convective system, MCS, and quasi-isolated strong convection, QISC), and region (i.e., northcentral, southcentral, northeast, and southeast). Overall, 135,890 deep convective storms were successfully sampled and had a mean LMD height of 8.6 km or tropopause-relative mean LMD height of −4.3 km; however, LMD heights were found to extend up to 2 km above the tropopause. May storms had higher mean tropopause-relative LMD heights, but July storms contained the highest overall LMD heights that more commonly extended above the tropopause. QISC had higher mean tropopause-relative LMD heights and more commonly had LMD heights above the tropopause while only a few MCSs had LMD heights above the tropopause. The regional analysis showed that northern regions have higher mean LMD heights due to large amounts of diurnally driven convection being sampled in the southern regions. By using the anvil top, the highest possible convective detrainment heights extended up to 6 km above the tropopause.