The International Cooperative for Aerosol Prediction (ICAP) Perspective on the Massive June 2020 Saharan Dust Event

Abstract:

During June 2020 a massive Saharan dust event propagated across the Atlantic Ocean and produced high aerosol optical depth (AOD) and surface particulate matter (PM) concentrations across the Caribbean and US gulf coast states that were far above climatological means. Ground-based measurements of PM, AOD, light scattering, absorption and visibility taken in the Greater Caribbean Region during the summer 2020 NASA-funded Caribbean Air-quality Alert and Management Assistance System-Public Health (CALIMA-PH) motivated a close look at predictive aerosol models that were forecasting dust plumes. The occurrence and progression of the June 2020 event was predicted by various global numerical weather prediction (NWP) centers that have included prognostic aerosols in their forecasting systems. Collectively, the centers represented in this study are contributing members of the International Cooperative for Aerosol Prediction (ICAP), a grass-roots community of model developers, data providers, and NWP center representatives. Eight models contributed forecasts to the ICAP multi-model ensemble (MME) during this event: the Barcelona Supercomputing Center, European Centre for Medium-Range Weather Forecasts, Japan Meteorological Agency, Finnish Meteorological Institute, NASA Goddard Space Flight Center, US National Centers for Environmental Prediction, UK Met Office, and US Navy Research Laboratory. We put this Saharan dust episode and the prevailing meteorological conditions in the context of model analyses and ground and space based observations taken over the course of the event, and we provide an evaluation of the individual ICAP models and the ICAP MME forecast and analysis performance in simulating the observed AOD and PM.