The Measured Relationship between Ice Water Content and Cloud Radar Reflectivity in Tropical Convective Clouds
| Autor: | Alfons Schwarzenboeck, Alain Protat, Marc Weber, Fabien Dezitter, Julien Delanoë, Craig R. Davison, Delphine Leroy, Lyle Lilie, Alice Grandin, Emmanuel Fontaine, John W. Strapp |
|---|---|
| Přispěvatelé: | Australian Bureau of Meteorology [Melbourne] (BoM), Australian Government, SPACE - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Met Analytics Inc. [Toronto], Laboratoire de météorologie physique (LaMP), Centre National de la Recherche Scientifique (CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS), Science Engineering Associates Inc., National Research Council of Canada (NRC), Airbus [France], Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) |
| Rok vydání: | 2016 |
| Předmět: |
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
Convection 020301 aerospace & aeronautics Atmospheric Science Jet (fluid) 010504 meteorology & atmospheric sciences Meteorology Scattering 02 engineering and technology [SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology Atmospheric sciences 01 natural sciences law.invention Altitude 0203 mechanical engineering law Content (measure theory) Convective storm detection Range (statistics) Environmental science Radar 0105 earth and related environmental sciences |
| Zdroj: | Journal of Applied Meteorology and Climatology Journal of Applied Meteorology and Climatology, American Meteorological Society, 2016, 55 (8), pp.1707-1729. ⟨10.1175/JAMC-D-15-0248.1⟩ Journal of Applied Meteorology and Climatology, 2016, 55 (8), pp.1707-1729. ⟨10.1175/JAMC-D-15-0248.1⟩ |
| ISSN: | 1558-8432 1558-8424 |
| DOI: | 10.1175/jamc-d-15-0248.1 |
| Popis: | In this paper, unprecedented bulk measurements of ice water content (IWC) up to approximately 5 g m−3 and 95-GHz radar reflectivities Z95 are used 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 g m−3 are also included for the first time in such an analysis, owing to improved bulk IWC probe technology and a flight program targeting high ice water content. Using a single IW–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 > 16 dBZ, as a result of the distortion of the IWC–Z95 relationship by non-Rayleigh scattering effects. A nonlinear relationship is proposed to reduce these errors down to 20% bias and 20%–35% rms differences. This nonlinear 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° ± 5°C level, the cruise altitude of many commercial jet aircraft, IWCs greater than 1.5 g m−3 were found exclusively in convective profiles. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|