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Observing and Monitoring the Climate System
Fiscal Year 2006 Accomplishments |
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Updated 3 December 2007
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Observing and Monitoring the Climate System |
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Recent Accomplishments
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The following are selected highlights of observations and monitoring activities supported by CCSP participating agencies, as reported in the fiscal year 2007 edition of the annual report, Our Changing Planet. The principal focus is on describing progress in implementing the observations that contribute to the CCSP mission. As a result, the chapter touches on some observing systems that are crucial to CCSP but are not included within the CCSP budget because they primarily serve other purposes. Observations and MonitoringInitial Ocean Observing System for Climate 56% CompletedThe NOAA Office of Climate Observation cooperates with 66 nations in implementing the internationally vetted design of an initial ocean observing system for climate,articulated in the WMO/IOC/United Nations Environment Programme plan for GCOS. Deployment of the observing system, planned for completion in 2012, is proceeding on schedule, with the United States currently supporting over 50% of the ocean-based observing platforms. Global Drifting Buoy Array 100% CompletedIn an historic milestone for international cooperation, the global drifting buoy array achieved its design goal of 1,250 data buoys in sustained service, thus becoming the first component of the Global Ocean Observing System and of GEOSS to be fully implemented. The United States currently maintains 1,000 of the buoys in the array. These buoys provide the operational instrumental data sets for describing the evolution of ocean surface circulation and sea surface temperature, which are used for testing climate models and enhancing long-range weather and seasonal-to-interannual climate predictions. Tropical Moored Buoy Network Extended into the Indian OceanWorking in close collaboration with Japan and India, the first six of a series of moored buoys have been deployed in the Indian Ocean for measurement of a comprehensive suite of ocean-atmosphere climate variables. This westward extension of the equatorial Pacific Tropical Atmosphere Ocean/Triangle Trans-Ocean array, whose long-term data have revolutionized understanding of the evolution of El Niño, is necessary to understand changes in Indian Ocean sea surface temperatures, which have recently been shown to be a cause of regional climate variability and change (including prolonged drought in the mid-latitudes, including the United States). Polar Region Observations [1]
Clues to Variability in Arctic Minimum Sea-Ice Extent [7]Perennial sea ice is a primary indicator of Arctic climate change. From 1979 to 2003, it decreased in extent by about 17%. Analysis of new satellite-derived fields of winds, radiative forcing, and advected heat reveals distinct regional differences in the relative roles of these parameters in explaining variability in the northernmost ice-edge position. In all six peripheral seas studied, downwelling long-wave radiation flux anomalies explain the most variability—approximately 40%—while northward wind anomalies are important in areas north of Siberia, particularly earlier in the melt season. Anomalies in insolation are negatively correlated with perennial ice retreat in all regions, suggesting that the effect of solar flux anomalies is overwhelmed by the long-wave influence on ice edge position. ICESat
MODIS
In the case of atmospheric features, MODIS has produced advanced, detailed observations of the global and regional extent of aerosols from natural and anthropogenic activity. MODIS not only observes more accurately the extent of cloudiness, including that associated with thin, wispy cirrus, that profoundly affects Earth’s radiation balance, but also cloud properties such as cloud phase (water or ice), optical depth (i.e., cloud thickness), and effective droplet radius. MODIS is also providing more detailed observations of land features such as surface reflectance (albedo), surface temperature, snow and ice cover, and the variability of vegetation type and vigor associated with seasonal and climatic (e.g., above and below average moisture) variability. The capability of MODIS to classify vegetation types and the photosynthetic activity of vegetation over the land as well as in the surface waters of the world’s oceans (i.e., phytoplankton) is leading to more accurate evaluation of spatial and seasonal changes in the global net productivity of Earth’s biosphere. MODIS’ capability for observing global processes and trends is leading to better understanding of natural and anthropogenic effects on the Earth-atmosphere system, and to better performance of general circulation models (GCMs). An example of the latter is the use of atmospheric winds derived from MODIS observations over the polar regions of the globe. These observations have been shown to improve the global predictive skill of several GCMs, both in the polar regions that are undergoing rapid change, and in the mid-latitudes. More than 100 “Direct-Broadcast” stations are now operating across the globe, enabling MODIS data to be obtained in near-real-time from the Aqua and Terra missions. About 800 user agencies or entities are now routinely using MODIS observations for regional applications or studies, including, for example, assessing the clarity of lakes (e.g., in Wisconsin and Minnesota), using observations of fire occurrence to strategically allocate fire-fighting resources (e.g., the U.S. Forest Service), and monitoring the extent of pollution (e.g., in China). QuikSCAT [2, 6]The SeaWinds instrument aboard the Quick Scatterometer (QuikSCAT) satellite has measured the speed and direction of wind over the surface of the oceans since 1999. Although launched as an experimental instrument, it has been assimilated pre-operationally into atmospheric weather prediction models (NOAA’s National Centers for Environmental Prediction, the European Centre for Medium-Range Weather Forecasts, and others) for the past 2 years. It is providing new insights on air-sea exchanges. Furthermore, the underlying radar backscatter data have been applied to climate change research concerning terrestrial high latitudes through studies of ice-layer formation. Solar Variability: SORCE
Constellation Observing System for Meteorology, Ionosphere, and ClimateThe Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) relies on radio occultation of signals from the Global Positioning System satellites. COSMIC satellites will take 2,500 vertical profile measurements every 24 hours in a nearly uniform distribution around the globe, filling in current data gaps over vast stretches of the oceans. The data’s high vertical resolution will complement the high horizontal resolution of other conventional weather satellite measurements. This will be the first time that the technique of radio occultation will be used on a large scale in real-time to provide continuous monitoring of worldwide atmospheric conditions. COSMIC builds on a series of previous research-oriented satellites, which were used to develop the measurement technique and establish the usefulness of the data in operational forecast systems. The remarkable stability,consistency, and accuracy of the measurements should be a boon to scientists quantifying long-term climate change trends. COSMIC was successfully launched on 14 April 2006, and its constellation of six small satellites will be transmitting atmospheric data to Earth for the next 5 or more years. ARM Mobile FacilityThe primary goal of the ARM Program is to improve the treatment of cloud and radiation physics in global climate models in order to improve the climate simulation capabilities of these models. These efforts have been enhanced by the addition of the ARM mobile facility (AMF) to study cloud and radiation processes in multiple climatic regimes. AMF can be deployed to sites around the world for durations of 6 to 18 months. Data streams produced by AMF will be available to the atmospheric community for use in testing and improving parameterizations in global climate models. The first deployment of AMF, in Point Reyes California—a collaboration between DOE and the DOD Office of Naval Research—made observations of marine stratus clouds and cloud-aerosol interactions. Observing Earth’s Mass Distribution Changes from Space [3, 4, 8]
Major climate events also influence Earth’s shape due to changes in the mass of water stored in oceans, continents, and the atmosphere. Over the past 3 decades, geodetic observations using satellite-laser ranging techniques have detected large-scale changes in the Earth’s oblateness. Researchers found that in the past 28 years, two large variations in Earth’s oblateness were connected with strong ENSO events. Longer term changes in Earth’s oblateness are explained by the redistribution of mass in the Earth’s mantle due to the slow release of stress from the weight of ice on landmasses during the last glaciation. However, the data sets show that the long-term post-glacial rebound was interrupted by an anomaly in oblateness during the period 1998 to 2002, although the geophysical cause of this anomaly remains unidentified. Data Management and InformationThe paragraph that follows and the accompanying text box highlight selected data management and information activities supported by CCSP-participating agencies. REASoN ProgramForty Cooperative Agreement projects that are part of NASA’s Earth Science Research, Education, and Applications Solutions Network (REASoN ) have completed their first year. The REASoN projects are part of NASA’s strategy to work with its partners to improve its existing data systems, guide the development and management of future data systems, and focus performance outcomes to further Earth science research objectives. In order to achieve these goals, the REASoN projects are organized to engage the science community and peer review process in the development of higher level science products; to use these products to advance Earth system research; to develop and demonstrate new technologies for data management and distribution; and to contribute to interagency efforts to improve the maintenance and accessibility of data and information systems. A list of ongoing activities under this program is available online.
References1) ACIA, 2005: Arctic Climate Impact Assessment. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 1042 pp.
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Polar systems may be especially sensitive to climate change and might provide early indications of climate change. They also interact with climate variability and change through several important feedback processes. Monitoring polar climate and understanding its feedbacks are key priorities described in the CCSP Strategic Plan. CCSP supports the creation of systematic data sets for parameters such as sea-ice thickness, extent, and concentration; land-ice and snow-cover mass balance; and surface temperature. The Arctic Climate Impact Assessment highlighted the impacts of changes in these and other variables. NSF and NOAA are jointly implementing an interagency activity entitled the 
Significant contributions are being made to CCSP’s polar observations by NASA’s 
The Moderate Resolution Imaging Spectroradiometer (MODIS) instrument has been operating successfully on NASA’s Earth Observing System (EOS) Terra
The Sun is the Earth’s primary energy source and external driver of climate variability. The Solar Radiation and Climate Experiment (SORCE) satellite, launched in 2003, is equipped with four instruments that measure variations in solar radiation much more accurately than previous instruments. SORCE is now making the first contiguous observations of solar variability across the full solar spectrum, from the far ultraviolet to near-infrared wavelengths. In June 2004, SORCE measured small changes in solar luminosity caused by the transit of Venus, demonstrating unprecedented precision. On 4 November 2004, SORCE documented the largest solar X-ray flare ever recorded and measured associated changes in total solar irradiance. SORCE’s operational life is expected to extend across the upcoming 2006-2007 solar minimum, a crucial period for estimating any long-term trend, such as that indicated by indirect measurements of past solar forcing. SORCE is expected to overlap with the Glory mission that will carry forward the total solar irradiance record after 2008, as discussed below. The continued measurements previously planned by the National Polar-Orbiting Operational Environmental Satellite System (NPOESS) through the Total Solar Irradiance Sensor (including a Total Solar Irradiance Monitor and Spectral Irradiance Monitor) were removed from the NPOESS program during the Nunn-McCurdy recertification process completed in June 2006. Agencies are currently assessing the impacts of this decision for solar irradiance monitoring.
The Gravity Recovery and Climate Experiment (GRACE) is a two-spacecraft mission, developed under a partnership between NASA and the German Aerospace Center. After two successful years of mission operation, significant multidisciplinary results using GRACE observations are being reported. The unprecedented accuracy of the measurements provides the opportunity to observe time variability in the Earth’s gravity field due to changes in mass distribution. Large variations in mass distribution occur predominantly over the continents, but smaller and slower signals caused by changes in ocean circulation and land ice sheets and glaciers are also detectable. One analysis using GRACE data determined that up to 10 cm (4 in) of groundwater accumulation is associated with heavy tropical rains, particularly in the Amazon Basin and Southeast Asia. 
