A constellation of low Earth orbit (LEO) and geostationary (GEO) satellites has been advancing the monitoring, assessment, and prediction of changes in the ozone layer, atmospheric composition, and air quality. Satellite-operating organizations are working to maximize observational coverage, ensure continuity, and foster innovation in applications. We invite contributions on algorithm development, calibration, and validation for measurements in ultraviolet, visible, near-infrared, shortwave infrared, and infrared spectral regions to enhance the information content of trace gases, greenhouse gases, and aerosol properties. We encourage research using measurements from single or multiple sensors, on the same satellite or across platforms, for applications including air quality monitoring, atmospheric composition change, and related topics. We seek presentations focused on civilian satellite sensors in LEO (e.g., CO2M, CrIS, TROPOMI, OMPS, VIIRS, Sentinel-5, METImage, IASI, GOSAT, MERLIN, 3MI, IASI-NG, EnMAP) and GEO (e.g., GEMS, TEMPO, Sentinel-4/Sentinel-5, IRS, ABI, AMI, AHI, FCI, GeoXO), as well as LEO-GEO synergies.