CER_ISCCP-D2like-Mrg_GEO-MODIS-DAY_Edition3A is the Clouds and the Earth's Radiant Energy System (CERES) Moderate Resolution Imaging Spectroradiometer (MODIS) and Geostationary Satellite (GEO) Cloud Retrievals in International Satellite Cloud Climatology Project (ISCCP) – Day 2like Format Daytime Edition3A data product. This product is a merge of data from the following platforms and instruments: Spinning Enhanced Visible and Infrared Imager (SEVIRI) on Meteosat Operational Programme 10 (METEOSAT-10); Japanese Advanced Meteorological Imager (JAMI) on The Multi-functional Transport Satellite 2 (MTSAT-2); SEVIRI on METEOSAT-9; Visible and Infrared Spin Scan Radiometer (GMS Series) on (VISSR-GMS) on Geostationary Meteorological Satellite-5 (GMS-5); SEVIRI on METEOSAT-8; Geostationary Operational Environmental Satellite (GOES) I-M IMAGER on Geostationary Operational Environmental Satellite 9 (GOES-9); GOES-11 IMAGER on GOES-11; GOES N-P IMAGER on GOES-13; GOES-8 IMAGER on GOES-8; GOES I-M IMAGER on GOES-10; SEVIRI on METEOSAT-7; MODIS on Terra; GOES N-P IMAGER on GOES-14; MVIRI on METEOSAT-5; GOES-12 IMAGER on GOES-12; GOES-15 IMAGER on GOES-15; MODIS on Aqua; JAMI on Multi-functional Transport Satellite 1 Replacement (MTSAT-1R). Data collection for this product is complete.The Monthly Gridded Cloud Averages (ISCCP-D2like-Mrg) data products contain monthly and monthly 3-hourly (GMT-based) gridded regional mean cloud properties as a function of 18 cloud types, similar to the ISCCP D2 product, where the cloud properties are stratified by pressure, optical depth, and phase. The merged (Mrg) product combines daytime cloud properties from Terra-MODIS (10:30 AM local equator crossing time LECT), Aqua-MODIS (1:30 PM LECT), and geostationary satellites (GEO) to provide the most diurnally complete daytime ISCCP-D2like product. The GEO cloud properties have been normalized with MODIS for diurnal consistency. The CERES MODIS-derived cloud properties are not the official NASA MODIS cloud retrievals but are based on the CERES cloud working group retrievals that are also available in other CERES products. The CERES MODIS-derived cloud properties provide coverage from pole to pole. The 3-hourly GMT-based GEO cloud properties come from five satellites at 8 km nominal resolution with limited coverage. The GEO daytime cloud retrievals incorporate only a visible and IR channel common to all geostationary satellites for spatial consistency. The geostationary calibration is normalized to Terra-MODIS. Each ISCCP-D2like file covers a single month.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. The first CERES instrument, the protoflight model (PFM), was launched on November 27, 1997, as part of the Tropical Rainfall Measuring Mission (TRMM). Two CERES instruments (FM1 and FM2) were launched into polar orbit on board the Earth Observing System (EOS) flagship Terra on December 18, 1999. Two additional CERES instruments (FM3 and FM4) were launched on board Earth Observing System (EOS) Aqua on May 4, 2002. The CERES FM5 instrument was launched on board the Suomi National Polar-orbiting Partnership (NPP) satellite on October 28, 2011. The newest CERES instrument (FM6) was launched on board the Joint Polar-Orbiting Satellite System 1 (JPSS-1) satellite, now called NOAA-20, on November 18, 2017.