HAL will be down for maintenance from Friday, June 10 at 4pm through Monday, June 13 at 9am. More information
Skip to Main content Skip to Navigation
Journal articles

The Measured Relationship between Ice Water Content and Cloud Radar Reflectivity in Tropical Convective clouds.

Abstract : In this paper we use unprecedented bulk measurements of ice water content (IWC) up to approximately 5 gm-3 and 95 GHz radar reflectivities (Z95) to analyze the statistical relationship between these two quantities and its variability. The unique aspect of this study is that these IWC – Z95 relationships do not use assumptions on cloud microphysics or backscattering calculations. IWCs greater than 2 gm-3 are also included for the first time in such analysis, owing to improved bulk IWC probe technology and a flight program targeting high ice water content. Using a single IWC – Z95 relationship allows for the retrieval of IWC from radar reflectivities with less than 30% bias and 40-70% rms difference. These errors can be reduced further down to 10-20% bias over the whole IWC range using the temperature variability of this relationship. IWC errors largely increase for Z95> 15-16 dBZ, due to the distortion of the IWC – Z95 relationship by non-Rayleigh scattering effects. A non-linear relationship is proposed to reduce these errors down to 20% bias and 20-35% rms differences. This non-linear relationship also outperforms the temperature-dependent IWC – Z95 relationship for convective profiles. The joint frequency distribution of IWC and temperature within and around deep tropical convective cores shows that at the -50°C ± 5°C level – the cruise altitude of many commercial jet aircraft – IWCs greater than 1.5 gm-3 were found exclusively in convective profiles.
Complete list of metadata

Cited literature [49 references]  Display  Hide  Download

Contributor : Catherine Cardon Connect in order to contact the contributor
Submitted on : Monday, November 9, 2020 - 4:49:16 PM
Last modification on : Tuesday, November 16, 2021 - 5:14:56 AM
Long-term archiving on: : Wednesday, February 10, 2021 - 7:34:55 PM


Publisher files allowed on an open archive



Alain Protat, Julien Delanoë, J. W. Strapp, E. Fontaine, D. Leroy, et al.. The Measured Relationship between Ice Water Content and Cloud Radar Reflectivity in Tropical Convective clouds.. Journal of Applied Meteorology and Climatology, American Meteorological Society, 2016, 55 (8), pp.1707-1729. ⟨10.1175/JAMC-D-15-0248.1⟩. ⟨insu-01322886⟩



Record views


Files downloads