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The Global Ensemble Forecast System - Aerosols (GEFS-Aerosols) was transitioned to operations on September 23, 2020. GEFS-Aerosols is an atmospheric composition model that integrates weather and air quality using the Finite Volume Cubed Sphere (FV3) core. The Global Systems Laboratory (GSL) led the project, with contributions from the Chemical Sciences Laboratory (CSL), the Air Resources Laboratory (ARL), NESDIS, (NOAA’s National Environmental Satellite, Data, and Information Service), and the National Weather Service’s Environmental Modeling Center.

GEFS-Aerosols produces seven-day forecasts of the global distribution of some primary air pollutants: smoke, soot, organic carbon, sulfate, and large and small particles of dust and sea salt - collectively known as aerosols. Because these aerosols affect the weather, the model also provides weather forecasts. The new model is also capable of predicting the atmospheric impact of volcanic eruptions, which can disperse quantities of ash and other particulates over wide areas.

“Several NOAA laboratories worked with the National Weather Service to produce major improvements to NOAA’s air quality modeling capabilities,” said Georg Grell, chief of the Global Systems Laboratory’s Environmental Prediction Advancement Division. “Now the developers as well as the broader modeling research community can contribute towards further improving it.”

The atmospheric chemistry component of GEFS-Aerosols is based on WRF-Chem, a community modeling system used by thousands of users worldwide. The aerosol modules are based on the NASA Goddard Chemistry Aerosol Radiation and Transport model (GOCART). Global anthropogenic emission inventories are derived from the Department of Energy’s Community Emissions Data System.

A new dust emissions algorithm was created and implemented in GEFS-Aerosols by scientists in ARL. The algorithm significantly improves the model's estimates of dust in the global atmosphere, thereby potentially improving weather and air quality forecasts.

The biomass burning plume rise module added in GEFS-Aerosols is from WRF-Chem, and it will also be used in the Rapid Refresh (RAP) and High-Resolution Rapid Refresh (HRRR) operational modeling systems. With the currently planned operational implementation of RAP and HRRR, NWS will become one of the first major weather forecast centers to successfully implement any type of real-time forecasted aerosol into an already world-class-operational NWP model.