In the Earth Observatory Item of the Day (EO IOTD) for November 30, 2023, "Filling an Air Pollution Data Gap," the work of Christoph Keller (610.1/MSU) and Emma Knowland (610.1/MSU) on developing and expanding the use of the GEOS-CF model is featured. "Goddard Earth Observing System Composition Forecast (GEOS-CF) incorporates timely weather observations and insights from years of satellite observations, plus a range of historical emissions inventories. It generates five-day forecasts for the whole atmosphere every day." In 2020, GEOS-CF was adapted as part of a pilot project called CityAQ, which resulted in greater air quality forecasts for certain cities. A new effort called CanAIRy, which began in 2021, also will utilize data from GEOS-CF and will expand upon the air quality information acquired from CityAQ.