Deep-inflow approach to mesoscale-organized and unorganized deep convection and the likely role of coherent structures

Representations of strongly precipitating deep-convective systems in climate models face two major challenges: 1) high sensitivity to approximations of turbulent entrainment of environmental air; 2) an unclear path to inclusion of mesoscale-organized systems. An alternative to traditional turbulent entrainment assumptions in deep convective parameterizations – Deep-Inflow Mixing – is presented, based on radar wind profiler observations of vertical mass flux from the Department of Energy GoAmazon2014/5 campaign. Updraft buoyancy computed with deep-inflow mixing and tropospheric thermodynamic properties yields predictive relationships to precipitation in both mesoscale-organized and unorganized convection. Results from reanalysis and satellite data show that this holds more generally: buoyancy from deep-inflow mixing yields a strong relation to precipitation across the tropics. Physical interpretation points to a strong role for coherent inflow typical of organized convection. This simultaneously provides a key step toward representing mesoscale-organized convection in climate models and removes a problematic dependence on traditional entrainment rates.