Global Change Master Directory

Global Change Master Directory
Name	Global Change Master Directory
Acronym	GCMD
Established	1990s
Type	data catalog
Parent	Earth Science Information Partners
Country	United States

Global Change Master Directory The Global Change Master Directory is an online catalog for Earth science and environmental datasets, supporting discovery, access, and use by researchers, policy makers, and practitioners. It aggregates metadata describing datasets from agencies, laboratories, universities, and international programs to facilitate interoperability among systems such as NASA, NOAA, USGS, ESA, and United Nations Environment Programme. The directory connects metadata to portals, archives, and initiatives including International Geosphere-Biosphere Programme, Group on Earth Observations, Intergovernmental Panel on Climate Change, and World Meteorological Organization.

Overview

The directory catalogs dataset descriptions, service endpoints, and thematic keywords for domains spanning climate change, oceanography, glaciology, remote sensing, and biodiversity. It supports metadata standards used by Dublin Core, ISO 19115, FGDC, and the Open Geospatial Consortium to enable harvesting with protocols like OAI-PMH and CSW. Users search across holdings contributed by organizations such as National Aeronautics and Space Administration, National Oceanic and Atmospheric Administration, United States Geological Survey, European Space Agency, and National Snow and Ice Data Center to find resources hosted at repositories like PANGAEA, Dryad, BODC, and COPERNICUS.

History and Development

Conceptual origins trace to collaborative programs in the early 1990s involving National Aeronautics and Space Administration and research initiatives such as Global Climate Observing System and International Council for Science. Development milestones align with major international efforts including the Earth Summit and the launch of Landsat missions, and integration with archives like NASA EOSDIS and NOAA National Centers for Environmental Information. The directory evolved through partnerships with projects including Global Earth Observation System of Systems, Group on Earth Observations, Committee on Earth Observation Satellites, and research centers such as Lamont–Doherty Earth Observatory and Jet Propulsion Laboratory.

Data Content and Standards

Metadata records describe datasets from sensors, models, and surveys such as MODIS, SEVIRI, GRACE, Argo (ocean) floats, and ICESat altimetry, and from field campaigns like International Geophysical Year derivatives and GEOTRACES. Records conform to community vocabularies and schemas including ISO 19115, Dublin Core, Federal Geographic Data Committee, and controlled lists used by Global Biodiversity Information Facility and International Oceanographic Commission. The directory registers variables, temporal and spatial coverage, formats such as NetCDF, HDF5, CSV, and service types including OPeNDAP, WMS, and WCS. It references datasets produced by institutions like Scripps Institution of Oceanography, National Center for Atmospheric Research, Lawrence Berkeley National Laboratory, and Pacific Northwest National Laboratory.

Access and Services

Search and discovery services support keyword, temporal, spatial, and platform-based queries, and interoperate via APIs with platforms such as Earthdata, GEOSS Portal, Data.gov, and Zenodo. The directory exposes metadata harvesting endpoints compatible with OAI-PMH and CSW and provides links to access services like Thredds Data Server and Esri ArcGIS Online. Users include researchers from University of Cambridge, Massachusetts Institute of Technology, California Institute of Technology, and agencies such as US Fish and Wildlife Service seeking provenance and citation details for datasets archived at centers like British Antarctic Survey and NOAA NCEI.

Governance and Partnerships

Management has involved collaborations among federal agencies, academic centers, and international bodies including NASA, NOAA, USGS, European Commission, United Nations Educational, Scientific and Cultural Organization, and consortia such as Earth Science Information Partners and Global Change Information System. Standards coordination engages stakeholders from Open Geospatial Consortium, World Data System, Digital Object Identifier registration agencies like CrossRef, and domain programs such as SOLAS and SPARC. Funding and oversight have intersected with initiatives like US Global Change Research Program and bilateral partnerships involving institutions such as NOAA Cooperative Institutes.

Impact and Use Cases

The directory underpins assessments and syntheses authored by panels such as the Intergovernmental Panel on Climate Change and supports operational services for disaster risk reduction activities coordinated with United Nations Office for Disaster Risk Reduction and International Strategy for Disaster Reduction. It enables scientists at Woods Hole Oceanographic Institution, National Center for Atmospheric Research, CSIRO, and JAMSTEC to locate datasets for studies of sea level rise, carbon cycle, land use change, and polar ice dynamics. Planners at organizations like World Bank and European Environment Agency use metadata to inform projects, and educators at institutions such as Stanford University and University of Oxford incorporate records into curricula and open science efforts.

Category:Earth science data