The U.S. Climate Reference Network (USCRN) is a network of climate stations developed by the National Oceanic and Atmospheric Administration (NOAA). The USCRN's primary goal is to provide future long-term homogeneous temperature and precipitation observations that can be coupled to long-term historical observations for the detection and attribution of present and future climate change.
Data from the USCRN is used in operational climate monitoring activities and for placing current climate anomalies into an historical perspective. The USCRN provides the United States with a reference network that meets the requirements of the Global Climate Observing System (GCOS). The network consists of 114 commissioned stations in the contiguous United States, 6 stations in Alaska, and 2 stations in Hawaii.
The USCRN Program Executive Director is Thomas Karl, Director of NOAA's National Climatic Data Center (NCDC). The program is managed and coordinated by the NCDC, a component of NOAA's National Environmental Satellite, Data, and Information Service (NESDIS).
The USCRN was established to help detect climate change in the United States. In order to assess the performance of the network in addressing this goal a performance measure (PM) was developed. This PM is an assessment of how closely the current and past configuration of the network captures the "true" national temperature and precipitation signal as defined by an area-averaged time series of annual temperature and precipitation derived from 4000 U.S. Cooperative Observer Program (COOP) Network stations scattered across the continental U.S. The configuration of the USCRN for a given point in time is used to select stations from the 4000 COOP station network, one station for each operating USCRN site (the one physically closest in location), and the time series derived from these stations is compared, statistically, to the time series derived from all 4000 stations. The result is a "variance explained" that measures how closely the "USCRN" time series follows the "true" time series.
The application which produces the statistics used to assess the PM is
under the configuration management of the NCDC, Scientific Services Division. The current PM
status documents are available upon request. Contact the USCRN
Climate Monitoring Principles (National Research Council 1999)
National Environmental Policy Act (NEPA) documents
One of the principal conclusions of the 1997 Conference on the World Climate Research Programme was that the global capacity to observe the Earth's climate system is inadequate and deteriorating worldwide and "without action to reverse this decline and develop the GCOS, the ability to characterize climate change and variations over the next 25 years will be even less than during the past quarter century" (National Research Council [NRC] 1999). In spite of the United States being a leader in climate research, we do not have, in fact, an observing network capable of ensuring long-term climate records free of time-dependent biases. Even small biases can alter the interpretation of decadal climate variability and change.
The NRC (1999) study further concluded that federal agencies and the scientific community at large should take action to:
- stabilize the existing observational capability;
- identify critical variables that are inadequately measured;
- build climate observing requirements into the operational programs as a high priority;
- revamp existing climate programs and some climate-critical parts of operational observing programs; and
- establish a funded activity for the development, implementation, and operation of climate-specific observational programs.
These recommended actions came as a result of a question asked by the chair of this study. "Are we making the measurements, collecting the data, and making it available in a way that scientists of both today and tomorrow will be able to effectively increase our understanding of natural and human-induced climate change?" (NRC 1999, page x).
Overall, the climate community is at a crossroads. On the one hand, we have done the best we can do to document regional, national, and global climate change. On the other hand, to ensure credibility of future climate change assessments, it is necessary for the scientific community to acknowledge that a crisis exists in the quality of our long-term observing systems – a crisis to which it must respond.
NOAA's response to the NRC concerns is the USCRN, a network of 114 stations deployed across the continental U.S., and with an ongoing effort to add 29 more stations in Alaska. As noted earlier, the primary goal of its implementation is to provide future long-term homogeneous observations of temperature and precipitation that can be coupled to past long-term observations for the detection and attribution of present and future climate change. Data from the USCRN will be used in operational climate monitoring activities and for placing current climate anomalies into an historical perspective. The USCRN will also provide the USA with a reference network that meets the requirements of the GCOS. Implementation of the USCRN is contingent on the availability of funding.
Who Can Benefit
The USCRN provides an opportunity for interagency cooperation and leveraging of resources that is unprecedented in the history of U.S. climate monitoring. In fact, a coordinated effort is crucial to its success. A joint effort can minimize the cost of establishing and operating the USCRN while maximizing the benefits and information obtained from the network. Coordination at the federal level is occurring at all of the project's stages: development and design of the system, procurement and evaluation of candidate instrumentation, installation and maintenance of the equipment, monitoring and data evaluation, and utilization of the data.
The USCRN system is being designed for future expansion, with data logger ports available to NOAA and other agencies for attaching additional sensors (e.g., USDA soil moisture, soil temperature, and evaporation; NSF and DOE trace gas; NWS humidity and atmospheric pressure, etc.).
As an inter-agency network, the data will have application to weather forecasting, agriculture, hydrology, and commercial interests, among others, in addition to its primary purpose of operationally monitoring climate anomalies and detecting climate change.
Examples of Potential Benefits
Over the last decade, the amount of money in our economy that is directly impacted by the reliability of NOAA's climate data has increased dramatically. Errors in the data which might not have mattered a decade ago can now cost individuals and corporations millions of dollars. With our existing network, these errors are guaranteed to occur. However, the Climate Reference Network would be able to provide these sectors of the economy with reliable data. For example:
- A power company assessing changes in demand needs to accurately determine how much of this year's increase or decrease in demand over last year is due to the differences in the climate between the two years versus changes in their consumers.
- The weather insurance and derivative industries, which provide a mechanism for energy producers and energy users to hedge their risks due to unusual climate, use NOAA temperature data to settle accounts. With $3 billion a year in U.S. option premium payments, every 1 degree F is equivalent to $60 million.
- Some public utilities have contracts for natural gas which specify that prices are raised or lowered depending on the severity of the winter as determined by NOAA data. For example, just one of the smaller natural gas companies in North Carolina with approximately 130,000 customers took in an extra $4.4 million last year with their Weather Normalization Adjustment, which is over 10% of their revenue.
The USCRN would provide important contributions to agriculture weather forecasting.
- Private industry often uses regional numerical models to provide these forecasts. The physics in these models are now so good that one of their main problems is inaccuracies in the initial conditions, namely errors in the data used to describe current conditions from which their short term frost and freeze forecasts are made. Having the highly accurate USCRN data will help them improve the forecasts used by agribusiness and other weather sensitive sectors of the economy.
- Highly accurate USCRN precipitation data would be used in hydrographic models to delineate flood zones and determine water resources.
Department of Interior/U.S. Geologic Survey
- Setting up USCRN sites in National Parks and Refuge lands will help USGS monitor changing climatic conditions in those areas.
- This will help USGS monitor the impacts of climate change on hydrology, water resources, and water users.
Department of Interior/National Park Service
- NOAA has a long history of cooperation with the National Park Service, placing COOP stations and now USCRN stations within parks to better monitor climate in these locations.
National Aeronautics and Space Administration (NASA)
- USCRN in situ data could be used for:
- calibration & validation of the satellite observations,
- determination and correction of intra-satellite and inter-satellite drift,
- creating value-added satellite products (for example, blended temperature and precipitation estimations),
- input into climate models and validation of climate model output.
Department of State
- The Department of State chairs interagency conventions, such as the Kyoto Protocol. The USCRN will feed into the GCOS, under the United Nations Framework Convention on Climate Change. In both of these cases, USCRN data could be utilized by the State Department to meet agency commitments.
- The State Department is interested in the long-range transport of aerosols; for example, carcinogenic aerosols from overseas reaching the western U.S. Associated health studies provide an impetus for the introduction of clean technology in Third World/developing countries. USCRN stations could help monitor such aerosols if they were equipped with the necessary instrumentation.
Centers for Disease Control & Prevention
- Real-time USCRN data could help identify where there is a current weather-related health crisis.
- Monitoring a changing climate is important for tracking the spread of diseases.
Federal Emergency Management Agency (FEMA)
- USCRN monitoring of climate and climate change will help FEMA better plan for & manage the country's response to disasters.
National Weather Service
- USCRN hourly data transmission will provide the NWS with additional real-time observations for forecast verification and weather monitoring, as well as for issuing weather forecasts, watches, and warnings, and updating flood forecasts.
National Science Foundation
- NSF global change research programs facilitate data acquisition and data management activities necessary for basic research on global change. The USCRN could supplement such NSF programs as CLIVAR and the LTER network.
Department of Agriculture/National Resources Conservation Service
- The USCRN could benefit the USDA in the following National Resources Conservation Service areas:
- Climate Change Activities (carbon sequestration)
- Agricultural Air Quality
- Water Supply Activities
- PRISM Project Baseline Spatial Climate Information
- National Drought Policy Commission (NDPC)
- Conservation Activities
- Weather Simulation Activities
- Engineering Design Activities
White House Office of Science & Technology Policy
- In April 1997, the White House OSTP submitted a report to Congress,
Science and Technology - Shaping the Twenty-First Century. This report
noted the importance of climate and climate monitoring:
- "Progress towards sustainability requires us to confront a variety of local, regional, and global environmental challenges, such as ..... understanding, mitigating, and adapting to climate change."
- "Critical and comprehensive review by scientists of the state of scientific understanding of environmental issues, and the synthesis and communication of the results to decision makers, is valuable for research and policy purposes alike."
- "Accurate long-term measurements are a necessity for accurate assessments and for improving the quality of environmental modeling."
- OSTP considers cooperative arrangements in climate monitoring important in the Environmental Monitoring and Research Initiative.