International Satellite Cloud Climatology Project (ISCCP) Stage D1 3-Hourly Cloud Products - Revised Algorithm in Hierarchical Data Format

ISCCP_D1_1 is the International Satellite Cloud Climatology Project (ISCCP) Stage D1 3-Hourly Cloud Products - Revised Algorithm data set in Hierarchical Data Format. This data set contains 3-hourly, 280 KM equal-area grid data from various polar and geostationary satellites. The Gridded Cloud Product contents are spatial averages of DX quantities and statistical summaries, including properties of cloud types. Satellites are merged into a global grid. Atmosphere and surface properties from TOVS are appended. Data collection for this data set is complete. ISCCP, the first project of the World Climate Research Program (WCRP), was established in 1982 (WMO-35 1982, Schiffer and Rossow 1983) to: produce a global, reduced resolution, calibrated and normalized radiance data set containing basic information on the properties of the atmosphere from which cloud parameters can be derived; stimulate and coordinate basic research on techniques for inferring the physical properties of clouds from the condensed radiance data set and to apply the resulting algorithms to derive and validate a global cloud climatology for improving the parameterization of clouds in climate models; and promote research using ISCCP data that contributes to improved understanding of the Earth's radiation budget and hydrological cycle. Starting in 1983 an international group of institutions collected and analyzed satellite radiance measurements from up to five geostationary and two polar orbiting satellites to infer the global distribution of cloud properties and their diurnal, seasonal and interannual variations. The primary focus of the first phase of the project (1983-1995) was the elucidation of the role of clouds in the radiation budget (top of the atmosphere and surface). In the second phase of the project (1995 onward) the analysis also concerns improving understanding of clouds in the global hydrological cycle. The ISCCP analysis combined satellite-measured radiances (Stage B3 data, Schiffer and Rossow 1985), Rossow et al. 1987) with the TOVS atmospheric temperature-humidity and ice/snow correlative data sets to obtain information about clouds and the surface. The analysis method first determined the presence of absence of clouds in each individual image pixel and retrieves the radiometric properties of the cloud for each cloudy pixel and of the surface for each clear pixel. The pixel analysis was performed separately for each satellite radiance data set and the results were reported in the Stage DX data product, which had a nominal resolution of 30 km and 3 hours. The Stage D1 product was produced by summarizing the pixel-level results every 3 hours on an equal-area map with 280 km resolution and merging the results from separate satellites with the atmospheric and ice/snow data sets to produce global coverage at each time. The Stage D2 data product was produced by averaging the Stage D1 data over each month, first at each of the eight three hour time intervals and then over all time intervals.

Data and Resources

Additional Info

Field	Value
Maintainer	Earthdata Forum
Last Updated	April 21, 2026, 00:37 (UTC)
Created	April 1, 2025, 16:42 (UTC)
accessLevel	public
bureauCode	{026:00}
catalog_conformsTo	https://project-open-data.cio.gov/v1.1/schema
harvest_object_id	a412e712-a7af-46cd-82f7-dd2465c54edf
harvest_source_id	b99e41c6-fe79-4c19-bbc3-9b6c8111bfac
harvest_source_title	Science Discovery Engine
identifier	10.5067/ISCCP/D1
license	https://www.usa.gov/government-works
modified	2026-04-13T22:16:00Z
programCode	{026:000}
publisher	NASA/LARC/SD/ASDC
resource-type	Dataset
source_datajson_identifier	true
source_hash	9179208de402494c7c508f4a4ab422f7b8175689a6696a42986640c18736966e
source_schema_version	1.1
spatial	["CARTESIAN",[{"Boundary":{"Points":[{"Latitude":-90,"Longitude":-180},{"Latitude":-90,"Longitude":180},{"Latitude":90,"Longitude":180},{"Latitude":90,"Longitude":-180},{"Latitude":-90,"Longitude":-180}]}}]]
temporal	1983-07-01/2009-12-31
theme	{"Earth Science"}