Evaluation of the BSC-DREAM8b regional dust model using the 3D LIVAS-CALIPSO product. (December 2018) - Konsta, Dimitra
Abstract: The ability of regional atmospheric models to accurately represent long-range transport of dust is crucial for describing dust effects on radiation and clouds and for reducing their uncertainties on these processes. The optimized CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) pure-dust product that provides the three-dimensional patterns of dust and its transport pathways is a unique tool that can address the aforementioned model's issues. In this study we use the CALIPSO dust extinction profiles as a tool for examining the performance of the regional dust model BSC-DREAM8b in space and time, for the period 2009–2013 over Northern Africa, the Mediterranean, Europe, Eastern North Atlantic and the Middle East. Our analysis suggests that the model overestimates the dust extinction coefficient above dust source regions in Sahara Desert especially at altitudes lower than 3 km at about 0.04 km −1 . We also found a slight underestimation of transported dust over Europe and Atlantic Ocean lower than 0.025 km −1 of extinction coefficient values all along the vertical column. Over the Mediterranean dust is overestimated (∼0.01 km −1 ) in layers higher than 1 km height. Dust in the Middle East is significantly underestimated by the model (∼0.05 km −1 ) all along the vertical column especially during warm seasons. The study also provides an analysis of the CALIPSO limitations and uncertainties on the detection of strong dust activity contributing to the differences between the simulations and observations above the dust sources of Bodelé and Algeria. Highlights: The LIVAS-CALIPSO product provides the three-dimensional patterns of pure dust. It can be used as a unique tool to address models' biases and reduce uncertainties in dust model simulations. BSC-DREAM8b underestimates transported dust over Europe and the Atlantic Ocean (0.025km -1 of dust extinction coefficient). The model overestimates dust load over the Mediterranean (~0.01km -1 ). It significantly underestimates dust over the Middle East (0.05km -1 ) over all heights especially during the warm season.