Global Change Master Directory

Global Change Master Directory. The Global Change Master Directory is a comprehensive metadata repository and data discovery tool developed by the National Aeronautics and Space Administration to facilitate access to worldwide Earth science data sets. It serves as a pivotal component of the Global Change Research Program, enabling researchers, educators, and policy makers to locate and utilize diverse environmental data. The directory's structured approach to cataloging data descriptions has made it an essential resource for interdisciplinary studies on climate change, oceanography, and ecosystem dynamics.

Overview

The primary function of the directory is to provide a centralized, searchable inventory of descriptive information, or metadata, for thousands of Earth system science data sets and services. It operates under the auspices of NASA's Earth Science Data and Information System project, which is managed at the Goddard Space Flight Center. By adhering to international metadata standards, the directory ensures interoperability with other major data systems, such as the Committee on Earth Observation Satellites and the Global Earth Observation System of Systems. This framework supports vital research initiatives like the Intergovernmental Panel on Climate Change assessments and the World Climate Research Programme.

History and development

The directory was initiated in 1987 following recommendations from the United States Congress and the Office of Science and Technology Policy to improve access to global change data. Its development was closely aligned with the launch of the U.S. Global Change Research Program and early Earth Observing System planning. Key milestones included integration with the International Directory Network and adoption of the Directory Interchange Format standard. Throughout the 1990s and 2000s, it evolved in concert with advancements in information technology and the growing data volumes from missions like the Terra satellite and the Aqua satellite.

Data structure and organization

Metadata within the directory is organized using a hierarchical structure based on the Directory Interchange Format, which is an implementation of the broader International Organization for Standardization metadata standards. Each record describes a data set using fields for title, summary, principal investigator, temporal coverage, spatial coverage, and data center, such as the National Snow and Ice Data Center or the Oak Ridge National Laboratory. The system supports sophisticated queries by geographic location, sensor type, and scientific discipline, linking users to data held at institutions like the Jet Propulsion Laboratory and the European Space Agency.

Usage and applications

Scientists and resource managers worldwide utilize the directory to locate data for modeling atmospheric circulation, tracking deforestation in the Amazon Basin, or studying sea surface temperature anomalies in the Pacific Ocean. It has been instrumental for projects under the International Geosphere-Biosphere Programme and for validating models from the National Center for Atmospheric Research. Educational organizations, including the University Corporation for Atmospheric Research, also employ it as a teaching tool. Furthermore, agencies like the United Nations Environment Programme and the World Meteorological Organization reference the directory for environmental reporting and policy development.

Related projects and integration

The directory is a foundational element within a larger ecosystem of data curation systems. It interoperates with the NASA Earthdata search portal and contributes metadata to the Group on Earth Observations portal. Its standards and protocols have influenced subsequent systems, including the Data Observation Network for Earth and the European Commission's INSPIRE directive. Collaborative relationships with the National Oceanic and Atmospheric Administration, the United States Geological Survey, and the Global Biodiversity Information Facility ensure its continued relevance in the era of big data and open science.

Category:NASA Category:Earth sciences data Category:Scientific databases