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The U.S. GCOS Program


To improve global atmospheric climate observing through a diverse and integrated set of global, regional, and bi-lateral observing activities.


  • Monitoring the impacts of and the response to climate change
  • Early detection of climate change due to human activity
  • Improving data for impact analysis
  • Reducing major uncertainties in long-term climate activities

Program Description

The U.S. GCOS program has been one of the leaders in the global effort to maintain systematic climate observations and the program provides support in three-tiered approach of global, regional, and bi-lateral support. As part of the global support for GCOS, and in response to a U.S. Presidential Climate Change Research Initiative (CCRI), the U.S. has formulated a Framework for International GCOS Support plan.  This plan focuses on the status of GCOS, what is needed to bring GCOS to its operational-design level, and the support needed from the scientific, donor, and host communities to implement selected improvements to it primarily through the support of GUAN and GSN stations, but also via support for the GCOS Lead Data Center at NCDC, the operation of the Global Observing System Information Center, as well as support to selected improvements in the Global Atmosphere Watch.  On the regional level, via State Department supported bi-lateral climate agreements with Australia and New Zealand, the program supports the Pacific Islands regional GCOS program; with the Pacific being of critical importance to climate (e.g., source of El Nino) and given the general sparseness of data from this critical climate region, a strong regional program in support of GCOS is a benefit to the global climate observing effort.  In the past year the U.S. (via the State Department) has entered into a number of important bi-lateral climate agreements.  Specifically, the U.S. GCOS Program Office is involved in funding projects with Australia, China, New Zealand, and South Africa.  These bi-laterals cover a wide range of projects dealing with climate prediction, ocean observing, stratospheric detection, water vapor measurements, capacity building and training, and communication of information, and will focus the attention and resources of all these countries towards developing a more sustainable and robust GCOS program.


The U.S. Global Climate Observing System (GCOS) program based at NOAA's National Climatic Data Center supports the international GCOS effort from an atmospheric and overall data management perspective. This support fits in with a proactive process approach for GCOS implementation planning with the goal of obtaining a sustainable and robust GCOS observing network for international atmospheric, oceanographic, and terrestrial climate observing. Actions have been taken and plans are in place regarding international, regional, bi-lateral, and U.S. national level GCOS activities. Performance measures are being used to determine where and how best to fill gaps in GCOS surface and upper air network global coverage. The U.S. has been involved with GCOS since its creation in 1992 as a result of the 2nd World Climate Conference in 1990. A considerable amount of work has been done by various federal agencies. In particular, federal agencies have supported the international GCOS Steering Committee, and the work of the GCOS data, space, and science panels, as they have engaged in planning GCOS, defining its requirements, and contributing parts of the initial system. NOAA’s National Climatic Data Center (NCDC) in Asheville, North Carolina, supports a number of GCOS data management activities and hosts the U.S. GCOS Program Office based in Silver Spring, Maryland. The primary focus of this office is to coordinate the development of a national GCOS program that involves all U.S. federal agencies with a role in climate observing and monitoring. As part of this effort, the U.S. national program has taken a three-tiered approach to fostering the GCOS program. This approach involves providing support: (1) Internationally to improve and enhance atmospheric monitoring stations in developing nations that require assistance as identified by the international GCOS Atmospheric Observations Panel for Climate; (2) regionally for observing system supporting, training workshops, and related projects such as those in the Pacific Islands region for ensuring a robust and sustainable GCOS observing program; and (3) on a bi-lateral basis with nations that have entered into agreements with the U.S. on improving climate observing activities. The U.S. GCOS Program Office has been involved in funding and or participating in bi-lateral atmospheric climate observing and related data management efforts projects with among others, Australia, China, New Zealand, South Africa, and the United Kingdom. Meteorological surface-based networks, utilized for climate purposes, make observations of important climate factors, atmospheric profiles, and pollutant emissions, aerosols, and ozone. These surface-based networks are intended to provide the basic observational set needed to define the status and trends in climate of the world, and also to calibrate and validate satellite-based observations. Although hundreds of millions of dollars are spent each year on developing and operating space-based observation systems, surface-based meteorological networks are “under reporting their observations in many parts of the developing world. This is because of declining economies and the lack of understanding of how these observations contribute to the global effort to monitor climate. Consequently, these networks are operating substantially below their design standards and important observations are either not being made, or are not being communicated to users. Workshops are being conducted to define GCOS deficiencies and, during the next several years, more detailed activities to improve the networks will be identified. The implementation of a GCOS Cooperation Mechanism (GCM) was begun in 2004 as a way of identifying resources (both financial and in-kind) to aid in improving the operation of GCOS monitoring stations in developing nations. The U.S. GCOS Program Office supports the GCM via the support of a full-time GCOS Implementation Manager who works to manage specific projects funded by donors. While the GCM has had some success, the fund could in fact be better utilized by many more donor nations interested in the sustainability of GCOS for climate monitoring purposes. The U.S. GCOS continues to be an active participant in and large support of the international GCOS program in a number of areas. These areas of support can be characterized in three categories: (1) Global; (2) regional and bilateral; and (3) support for reference observing systems.

Overall GCOS Objectives

GCOS is intended to meet the needs for:

  • Climate system monitoring, climate change detection and monitoring the impacts of and the response to climate change, especially in terrestrial ecosystems and mean sea-level;
  • Climate data for application to national economic development;
  • Research toward improved understanding, modelling and prediction of the climate system.

GCOS priorities are:

  • Seasonal-to-inter-annual climate prediction;
  • The earliest possible detection of climate trends and climate change due to human activities;
  • Reduction of the major uncertainties in long-term climate prediction;
  • Improved data for impact analysis.
  • GCOS will build, to the extent possible, on existing operational and research observing, data management and information distribution systems, and further enhancements of these systems. The GCOS will be based upon, inter alia :
  • Existing and enhanced World Weather Watch (WWW) systems;
  • The Global Atmosphere Watch (GAW) and related atmospheric constituent observing systems;
  • The Global Ocean Observing System (GOOS) for physical, chemical and biological measurements;
  • The Global Terrestrial Observing System (GTOS) for land surface ecosystem, hydrosphere, and cryosphere measurements;
  • The maintenance and enhancement of programmes monitoring other key components of the climate system, such as terrestrial ecosystems (including the International Geosphere-Biosphere Programme (IGBP)), as well as clouds and the hydrological cycle, the earth's radiation budget, ice sheets and precipitation over the oceans (including the World Climate Research Programme (WCRP));
  • Programmes to monitor the key physical, chemical and biological aspects of the impacts of climate change (including the World Climate Impact Assessment and Response Strategies Programme);
  • Data communication and other infrastructures necessary to support operational climate forecasting (including the World Climate Data and Monitoring Programme (WCDMP) and the Climate Information and Prediction Services (CLIPS)).

Data Access

Related Documentation Spearheaded by the U.S. GCOS Program Office

A. Strategic Planning

1) Strategic Plan for the U.S. Integrated Earth Observation System, Section 4: Understand, Assess, Predict, Mitigate, And Adapt To Climate Variability And Change [pages 98-105]
2) As part of that strategic plan the following was also developed "Technical Reference Document Understand, Assess, Predict, Mitigate, and Adapt to Climate Variability and Change

B. High-Level Reporting to the UNFCCC (via the State Department)

1) Third U.S. Climate Action Report (2002); chapter on Sustained Observations [pages 137-147 or pdf pages 143-153]
2) Fourth U.S. Climate Action Report (2007); chapter 8 on Research and Systematic Observation
3) Fifth U.S. Climate Action Report (2010); chapter 8 on Research and Systematic Observation

C. Documentation of Climate Observing Efforts Across the Federal Government

Other Information