Microphysical observations during FASTEX from airborne doppler radar and in-situ measurements

• Published in: Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere
• Main Authors: Protat, Alain, Lemaître, Yvon, Bouniol, Dominique, Black, R.
• Other Authors: Centre d'étude des environnements terrestre et planétaires (CETP), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), NOAA Atlantic Oceanographic and Meteorological Laboratory (AOML), National Oceanic and Atmospheric Administration (NOAA)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2000
• Subjects: [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]; [SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology; North Atlantic
• Online Access: https://hal.science/hal-01660290; https://doi.org/10.1016/S1464-1909(00)00159-3

International audience A major objective of FASTEX is to document the three-dimensional dynamic and microphysical structure of the North-Atlantic frontal cyclones in their mature stage at different scales of motion. In this paper, we combine the airborne Doppler radar and microphysical 2D-C and 2D-P probes data to recover the 3D microphysical and radiative properties of the IOP16 and IOP12 frontal cyclones (terminal fall velocity, cloud and precipitation water contents, precipitation fall rate, effective radius). The first step is to derive statistical relationships between the microphysical quantities and reflectivity from the 2D-P and 2D-C probes. Then, the Doppler-derived 3D reflectivity field is combined with these statistical relationships to access the 3D microphysical fields. However, before completing these steps, it is mandatory (i) to get an absolute calibration of the radar, and (ii) to determine the type of ice particles. For this purpose, we developed a new statistical method to retrieve statistical relationships between terminal fall speed and reflectivity from Doppler radar data. It is shown that the comparison between the radar-derived and in-situ reflectivities and statistical relationships in liquid and ice phases permit to overcome those two problems.