Open AccessComparison of Airborne In Situ, Airborne Radar–Lidar, and Spaceborne Radar–Lidar Retrievals of Polar Ice Cloud Properties Sampled during the POLARCAT Campaign
Author(s) -
Julien Delanoe͏̈,
Alain Protat,
Olivier Jourdan,
Jacques Pelon,
Mathieu Papazzoni,
Régis Dupuy,
Jean-François Gayet,
Caroline Jouan
Publication year - 2013
Publication title -
journal of atmospheric and oceanic technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.774
H-Index - 124
eISSN - 1520-0426
pISSN - 0739-0572
DOI - 10.1175/jtech-d-11-00200.1
Subject(s) - lidar , remote sensing , environmental science , radar , satellite , effective radius , meteorology , cloud top , geology , computer science , geography , telecommunications , physics , quantum mechanics , galaxy , engineering , aerospace engineering
International audienceThis 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