The NASA Aerosol, Clouds, Convection and Precipitation (ACCP) Study (https://vac.gsfc.nasa.gov/accp/) convened a workshop in November 2020 to understand the future of modeling aerosols, clouds, convection, and precipitation and how satellite data can contribute to that future. ACCP is a project to define a satellite mission to be launched late in the 2020s to advance cloud and aerosol science, following the recommendations of the latest NASA Decadal Survey (https://doi.org/10.17226/24938).
The ACCP modeling workshop goal was to answer the following questions:
What will be the critical science questions for clouds and aerosols in 10 years?
Where will simulations of clouds and aerosols across scales of space (process models to global) and time (nowcasting to climate prediction) be in 10 years?
What data will be available from space? What data would provide the most benefit?
What are the state-of-the-art methods for confronting models with cloud and aerosol observations, including assimilation and climatological analysis techniques?
The virtual workshop was anchored by a series of prerecorded talks. (Talks are available for viewing at www.cgd.ucar.edu/events/2020/ACCP/.) Two days of synchronous sessions focused on discussion of the talks, along with small group breakout exercises. After an introduction to the ACCP concept came a panel discussing the future of modeling clouds and aerosols across scales. Participants were then asked to contribute their ideas. On the second day, there were two panel discussions. First came a discussion of the future of satellite observing systems. Second was a discussion of model–data synthesis methods. Finally, participants were asked to develop their own model–data synthesis proposal.
The meeting began with an overview of the ACCP mission concept by Graeme Stephens (NASA–JPL). ACCP is a satellite mission for clouds and aerosols, likely anchored by advanced active lidar and radar systems in space, designed to observe detailed aerosol profile and type information, as well as cloud microphysics and dynamics. ACCP will integrate across sensors and observational types to get multispectral views of the same scenes, with better resolution than is available today. Launch is scheduled for 2027 or 2029. ACCP is being thought of as a comprehensive mission that may comprise more than one platform and more than one orbit plane (i.e., inclined and polar), with multiple combinations of sensors.