Radar reflectivity as a proxy for convective mass transport

A methodology for using radar reflectivity as a direct observation of vertical transport of mass from the boundary layer to the upper troposphere and lower stratosphere is investigated and the level of maximum detrainment (LMD) is proposed. The case investigated is the 26 January 1999 squall line from the TRMM-LBA field campaign. Echo top heights and dual-Doppler derived divergence profiles are used to define the mass detrainment range. Anvil ice water content, with a simple correction for ice fall-speed, is found to be a good proxy for both the LMD, which for the storm analyzed is 13.75 km, and for the detrainment range of 6 to 20 km. More cases need to be analyzed to confirm the strength of this methodology, but the case study presented shows a strong correlation between anvil properties determined from radar reflectivity and the mass detrainment profile. Thus, radar reflectivity can be used as an indicator of the LMD to test model convective and transport parameterizations. Application of this methodology to non-dual Doppler radar (e.g. NEXRAD network) will be discussed.