JpGU-AGU Joint Meeting 2020

Presentation information

[E] Poster

A (Atmospheric and Hydrospheric Sciences ) » A-AS Atmospheric Sciences, Meteorology & Atmospheric Environment

[A-AS09] Cloud-Resolving Model Simulations for Climate and Weather Studies

convener:Toshihisa Matsui(NASA Goddard Space Flight Center), Masaki Satoh(Atmosphere and Ocean Research Institute, The University of Tokyo), Wei-Kuo Tao(NASA Goddard Space Flight Center)

[AAS09-P01] Polarimetric Radar Characteristics of Simulated and Observed Intense Convective Cores for a Midlatitude Continental and Tropical Maritime Environment

*Toshihisa Matsui1,2, Brenda Dolan3, Takamichi Iguchi1,2, Steven A. Rutledge3, Wei-Kuo Tao1, Stephen Lang1,4 (1.NASA Goddard Space Flight Center, 2.ESSIC University of Maryland, 3.Colorado State University, 4.Science Systems and Applications, Inc)

Keywords:Polarimetric radar, continental and maritime deep convection, cloud-resolving model

This study contrasts midlatitude continental and tropical maritime deep convective cores using polarimetric radar observables and retrievals from selected deep convection episodes during the MC3E and TWPICE field campaigns. The continental convective cores produce stronger radar reflectivities throughout the profiles, while maritime convective cores produce more positive differential reflectivity (Zdr) and larger specific differential phase (Kdp) above the melting level. Hydrometeor identification retrievals revealed the presence of large fractions of rimed ice particles (snow aggregates) in the continental (maritime) convective cores, consistent with the Zdr and Kdp observations. The regional cloud-resolving model simulations with bulk and size-resolved bin microphysics are conducted for the selected cases, and the simulation outputs are converted into polarimetric radar signals and retrievals identical to the observational composites. Both the bulk and the bin microphysics reproduce realistic land and ocean (L-O) contrasts in reflectivity, polarimetric variables of rain drops, and hydrometeor profiles, but there are still large uncertainties in describing Zdr and Kdp of ice crystals associated with the ice particle shapes/orientation assumptions. Sensitivity experiments are conducted by swapping background aerosols between the continental and maritime environments, revealing that background aerosols play a role in shaping the distinct L-O contrasts in radar reflectivity associated with raindrop sizes, in addition to the dominant role of background thermodynamics.