Comparison of airborne in-situ, airborne radar-lidar, and spaceborne radar-lidar retrievals of polar ice cloud properties sampled during the POLARCAT campaign

• Published in: Journal of Atmospheric and Oceanic Technology
• Main Authors: Delanoë, Julien, Protat, Alain, Jourdan, Olivier, Pelon, Jacques, Papazzoni, Mathieu, Dupuy, Régis, Gayet, Jean-François, Jouan, Caroline
• Other Authors: 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), Centre for Australian Weather and Climate Research (CAWCR), Laboratoire de météorologie physique (LaMP), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), TROPO - LATMOS
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2013
• Subjects: Aircraft observations; Cloud retrieval; Lidars/Lidar observations; Radars/Radar observations; Remote sensing; Satellite observations; [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]; [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology; [SDE.MCG]Environmental Sciences/Global Changes; [SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology; Arctic
• Online Access: https://hal.science/hal-00730535; https://hal.science/hal-00730535/document; https://hal.science/hal-00730535/file/%255B15200426%2520-%2520Journal%2520of%2520Atmospheric%25.pdf; https://doi.org/10.1175/JTECH-D-11-00200.1

International audience This study illustrates the high potential of RALI, the French airborne radar-lidar instrument, for studying cloud processes and evaluating satellite products when we have satellite overpasses. We demonstrate, for an Arctic Nimbostratus ice cloud collected on 1 April 2008 during the POLARCAT campaign, the capability of this synergistic instrument to retrieve cloud properties and to characterize the cloud phase at scales smaller than a kilometer which is crucial for cloud process analysis. A variational approach, which combines radar and lidar, is used to retrieve IWC, extinction and effective radius. We show that the combination of radar and lidar provides better retrievals than stand-alone retrievals, and that in general the radar overestimates and the lidar underestimates IWC. As the sampled ice cloud was simultaneously observed by CloudSat and CALIPSO satellites, we show a new way to assess satellite cloud products by combining in-situ and active remote sensing measurements. It was then possible to compare RALI to three satellite ice cloud products: CloudSat, CALIPSO and DARDAR.