The cloudy atmospheric boundary layer over the subtropical South Atlantic Ocean: Airborne-spaceborne lidar observations and numerical simulations

• Published in: Journal of Geophysical Research
• Main Authors: Cosma-Averseng, Stéphanie, Flamant, Cyrille, Pelon, Jacques, Palm, Stephen P., Schwemmer, Geary K.
• Other Authors: Service d'aéronomie (SA), 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), Science Systems and Applications, Inc. Lanham (SSAI), NASA Goddard Space Flight Center (GSFC)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2003
• Subjects: Boundary layer processes; Numerical modeling and data assimilation; Atmospheric Dynamics; atmospheric boundary layer; subtropical South Atlantic Ocean; lidar; meso-NH numerical simulations; Lidar In-Space Technology Experiment; [SDU]Sciences of the Universe [physics]; South Atlantic Ocean
• Online Access: https://hal.science/hal-04110036; https://hal.science/hal-04110036/document; https://hal.science/hal-04110036/file/Journal%20of%20Geophysical%20Research%20Atmospheres%20-%202003%20-%20Cosma%E2%80%90Averseng%20-%20The%20cloudy%20atmospheric%20boundary%20layer%20over%20the.pdf; https://doi.org/10.1029/2002JD002368

International audience This paper focuses on the structure of the marine boundary layer in an convergence region between easterly (trade winds) and westerly flows, over the Subtropical South Atlantic Ocean on 15 September 1994 using an unprecedented combination of spaceborne and airborne lidar observations, airborne Radar Ocean Wave Spectrometer and dropsondes system, and three-dimensional modeling. Methodologies previously developed to determine the marine atmospheric boundary layer (MABL) depth and cloud top heights from airborne lidar measurements are successfully applied to spaceborne measurements. Nested numerical simulations have been performed in this case study. It is shown that the MABL structure in this region (observed with lidar and simulated) collapsed dramatically in connection with a marked decrease of wind speed and near-zero turbulent kinetic energy due to specific synoptic conditions.