Classification and Characterization of Tropical Precipitation Based on High-Resolution Airborne Vertical Incidence Radar. Part II: Composite Vertical Structure of Hurricanes versus Storms over Florida and the Amazon

Abstract

High-resolution airborne measurements of vertical incidence radar reflectivity and Doppler velocity, as well as coincident upwelling 85-GHz radiances, are analyzed for several Atlantic Ocean hurricanes and for numerous convection-generated systems in Florida and Amazonia. Characteristic reflectivity, hydrometeor motion, and vertical air motion profiles of convective and stratiform precipitation are compared and related to their ice-scattering signature, with an emphasis on the difference between hurricanes and convection-generated storms. Hurricanes are found to be largely and clearly stratiform, displaying a remarkably narrow echo and vertical velocity spectrum. Air currents are inferred to be rising steadily at all levels, even in stratiform regions. Land-based, convection-generated stratiform regions tend to experience low-level descent and mid- to upper-level ascent, although the vertical velocity variability is large. Florida storms produce little stratiform precipitation. Their spectrum of echo and updraft strengths is broad, including some of the highest reflectivities aloft, resulting in very low 85-GHz radiances. Amazonian storms are relatively weak and are more ?maritime? in echo, vertical velocity, and ice-scattering characteristics, when compared with those in Florida, especially during a westerly low-level wind regime.