Flow Simulations from Spatial Patterns of Reconstructed Precipitation Radar Patterns of Hurricanes

Gorgucci et al. (2006) showed that a parameter space defined by several polarimetric radar variables could be used to characterize the shape of raindrops. This study has been extended using the so-called self-consistency analysis to identify rainfall regimes, specifically warm rain coalescence compared to the melting of large ice particles that have grown by riming. For a given rainfall regime, the behavior of Kdp/Z (where Kdp is the specific differential phase and Z is the linear reflectivity) plotted against Zdr (differential reflectivity) in rain-only regions is useful in identifying precipitation physics. Kdp is proportional to water mass content and mass-weighted oblateness ratio, whereas Zdr is a measure of particle oblateness of the largest drops in a sample volume. Z is proportional to concentration and diameter. Using data from polarimetric radar observations at several places (both tropical and mid-latitude) around the globe we demonstrate microphysical variability in rainfall associated with intraseasonal variability, differences in organization (isolated convection vs. organized), and regional variability. Several of these datasets have resulted from TRMM and GPM field campaigns, including the Mid-Latitude Continental Convective Clouds Experiment (MC3E) and Iowa Flood Studies (IFloodS). Implications for Z-based rain estimation as used by the TRMM and GPM precipitation radars will be discussed. This technique could also be applied to the nation's NEXRAD WSR-88DP data to better understand the microphysical characteristics of rainfall across the U.S.