GLOBE Clouds with Satellite Collocation Annual Datasets

Date of data collection: Multi-year data set

Geographical location of data collection: Global

Data description:

The NASA GLOBE Clouds team at NASA Langley Research Center in Hampton, Virginia, USA receives all overhead cloud reports from human observers submitted through the GLOBE (Global Learning and Observations to Benefit the Environment) Program. The ground-based cloud observations submitted through various protocols and methods, including the GLOBE Observer mobile app, are then collocated with satellite observations of clouds from various Earth-observing platforms, a process referred to as a satellite comparison.

The GLOBE Clouds data and matching satellite data are provided as CSV files for the period named (some files are compressed into ZIP format if they were too large). These data files include all clouds data received by GLOBE and matched to satellite data by the NASA Langley Research Center GLOBE Clouds team as of the date in the file name (example: 2017_GLOBE-AnnualCloudData_2022-03-18_v3-0.csv).

Version notes:

• Version 1.1 includes all data from Version 1.0, plus data that was received after the Version 1.0 files were generated.
• Version 2.0 data includes additional satellite matches after a correction to the code used for matching, an error pointed out by a regular GLOBE Observer contributor. The window before or after a satellite overpass to match with ground data was incorrectly set at 0.15 hours (9 minutes) rather than the full 15 minutes (0.25 hours) intended. All data starting from 2017-01-01 has been reprocessed using the new code, resulting in an additional 54,000+ satellite matches, a 36% increase. The 2018 Spring Data Challenge data file was replaced in March 2021 with a new version including some data missing from the December 2020 version.
• Version 3.0 data changes the -99 value that used to represent "no data" is now left blank (no quality assurance flags added).
• Versions 3.1 through 3.4 are processed using the 3.0 process, but at later dates (noted in the file name) and may include additional data submitted to the database later.

The NASA GLOBE Clouds: Documentation on How Satellite Data is Collocated to Ground Cloud Observations (https://doi.org/10.5281/zenodo.18760289) is a guide to how the ground-satellite collocation or satellite comparison is done by the team. A full description of The GLOBE Program’s dataset can be found in the GLOBE Data Users Guide. 

Data Derived from another source:

This dataset features data from CALIPSO as well as products related to GOES, Himawari, Meteosat, Aqua, Terra, and NOAA-20 from CERES FLASHFlux and SatCORPS.

The data obtained from NASA Langley Research Center (Langley) and GLOBE are free of charge for use in research, publications and commercial applications. When data from NASA Langley and GLOBE are used in a publication, we request this acknowledgment be included: "These data were obtained from NASA Langley Research Center and the GLOBE Program." Please include such statements, either where the use of the data or other resource is described, or within the Acknowledgements section of the publication.

Acknowledgements: GLOBE Clouds at NASA Langley Research Center would like to thank the following teams for their support and collaboration: CALIPSO, CERES, FlashFLUX, SatCORPS, and ASDC.