CERES_EBAF-TOA_Edition4.2.1 is the Clouds and the Earth's Radiant Energy System (CERES) Energy Balanced and Filled (EBAF) Top-of-Atmosphere (TOA) Monthly means data in netCDF format Edition 4.2.1 data product. Data was collected using the CERES Scanner instruments on the Terra, Aqua, and NOAA-20 platforms. Data collection for this product is ongoing.CERES_EBAF-TOA_Edition4.2.1 data are monthly and climatological averages of TOA clear-sky (spatially complete) fluxes and all-sky fluxes, where the TOA net flux is constrained to the ocean heat storage. EBAF-TOA provides some basic cloud properties derived from high-resolution imager data alongside TOA fluxes. The Moderate-Resolution Imaging Spectroradiometer (MODIS) imagers Terra and Aqua and the Visible Infrared Imaging Radiometer Suite (VIIRS) are used for NOAA-20. Observed fluxes are obtained using cloud properties derived from narrow-band imagers onboard Earth Observing System (EOS) Terra and Aqua and NOAA-20 satellites and geostationary satellites to fully model the diurnal cycle of clouds. The computations are also based on meteorological assimilation data from the Goddard Earth Observing System (GEOS) Versions 5.4.1 models until March 2022 and the Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2). Unlike other CERES Level 3 clear-sky regional data sets that contain clear-sky data gaps, the clear-sky fluxes in the EBAF-TOA product are regionally complete. The EBAF-TOA product is the CERES project's best estimate of the fluxes based on all available satellite platforms and input data. Only Terra data is used from March 2000 to June 2002; Terra and Aqua are combined from July 2002 until March 2022; and only NOAA-20 is used after March 2022. A correction created from an overlap period with time periods when both Terra and Aqua are available is used to adjust the single satellite periods.CERES is a key Earth Observing System (EOS) program component. The CERES instruments provide radiometric measurements of the Earth's atmosphere from three broadband channels. The CERES missions follow the successful Earth Radiation Budget Experiment (ERBE) mission. Two CERES instruments (FM1 and FM2) were launched into polar orbit onboard the Earth Observing System (EOS) flagship Terra on December 18, 1999. Two additional CERES instruments (FM3 and FM4) were launched onboard Earth Observing System (EOS) Aqua on May 4, 2002. The newest CERES instrument (FM6) was launched onboard the Joint Polar-Orbiting Satellite System 1 (JPSS-1) satellite, now called NOAA-20, on November 18, 2017.