Toward Improving Ice Water Content and Snow-Rate Retrievals from Radars. Part I: X and W Bands, Emphasizing CloudSat

• DOI: 10.1175/jamc-d-15-0290.1
• Publication Date: 2016-04-06T20:45:56Z
• Authors: Andrew J. Heymsfield; Sergey Y. Matrosov; Norman B. Wood
• Keywords: Liquid water content

Abstract Microphysical data and radar reflectivities ( Z e , −15 < 10 dB) measured from flights during the NASA Tropical Clouds, Convection, Chemistry Climate field program are used to relate at X W band ice water content (IWC). Because nearly collocated IWC were each directly measured, – relationships could be developed directly. Using particle size distributions masses evaluated based on direct measurements, reflectivity–snowfall rate S ) also derived. For dB, herein yield larger than given by retrievals earlier relationships. The sensitivity of reflectivity distribution size-dependent mass, shape, orientation introduces significant uncertainties in retrieved quantities since these factors vary substantially globally. To partially circumvent uncertainties, a W-band relationship is relating four years global CloudSat observations immediately above melting layer rain rates base layer. supporting assumptions that mass flux constant through layer, air temperature 0°C, well constrained. Where > this conforms relationships, but for dB it yields higher . not all retrieval algorithms estimate either or both authors use large aircraft-derived dataset can then estimated vice versa.