|Achieving the goals
of the USGCRP program elements requires, in many cases, the documentation
of change and the existence of long-term data records. The USGCRP agencies,
through space-based and ground-based activities, provide many of the required
long-term observations. The program also directs particular attention to
the development and implementation of research observing systems to address
new requirements arising from improved scientific understanding and from
operational resource managers and policy imperatives.
Space-based systems have the unique advantage of obtaining global spatial
coverage, particularly over the vast expanses of the oceans, sparsely populated
land areas (deserts, mountains, forests, and polar regions), and the mid-
and upper troposphere and stratosphere. They provide unique measurements
of the Earth’s radiation budget; solar output; vegetation cover; atmospheric
ozone; stratospheric water vapor and aerosols; greenhouse gas distributions;
sea level and ocean state; ocean surface state, level, and winds; weather;
and tropical precipitation, among others.
But satellite observations alone are not sufficient; they require in-situ
measurements for calibration and validation. In-situ observations are required
for the measurement of parameters that cannot be estimated from space platforms
(e.g., biodiversity, groundwater, carbon sequestration at the root zone,
and subsurface ocean parameters). They also provide long time series of
observations required for the detection and diagnosis of global change,
such as surface temperature, precipitation and water resources, weather
and other natural hazards, the emission or discharge of pollutants, and
the impacts of multiple stresses on the environment due to human and natural
To meet the need for the documentation of global changes on a long-term
basis, the USGCRP integrates observations from both research and operational
systems, such as NOAA’s operational weather satellites and surface-based
stations. The latter are essential for the USGCRP but are not included
within the USGCRP programs or budget presentation.
Following are some of the specific observation and monitoring activities
that support the various program elements.
Earth’s Climate System
Data collection from
the EOS-AM satellite will provide observations of cloud structure, water
vapor distribution, aerosol particles, trace gases, and terrestrial and
ocean properties. These data are required for improved monitoring and modeling
of air-land and air-sea interaction and of the exchanges of carbon, energy,
Launch of JASON-1 will
provide altimetry measurements for ocean circulation and sea-level change
required for the monitoring and prediction of El Niño events.
Launch of ACRIMSAT will
provide accurate data to monitor solar irradiance, and for studies of solar-terrestrial/atmosphere
Launch of the Seawinds
satellite will provide more accurate measurements of ocean surface winds
and wind stress required to run ocean models for El Niño prediction.
The data are also required to improve weather forecasting.
Further development of
a Climate Reference Network, consisting of several hundred stations from
the network of 7000 sites that measure temperature and precipitation daily,
will provide stable measurements of climate change with the requisite continuity
over the instrumental record.
Deployment of a pilot
climate monitoring array in the tropical Atlantic, including moorings,
surface drifting buoys, and autonomous profiling floats, will complement
similar platforms in the tropical Pacific and expand the global domain
of ocean surface and subsurface observations. Similar deployments will
be carried out in the North Pacific and the Indian Ocean.
A third Atmospheric Radiation
Measurement Station in the western Pacific will provide data on the effects
of clouds on the Earth’s radiative energy balance, a major source of uncertainty
in climate models.
Figure 8. Ocean circulation profiling floats
(See Appendix E for additional information)
Biology and Biogeochemistry
Launch of the Vegetation
Canopy Lidar (VCL) satellite will provide detailed measurements of the
vertical structure of the vegetation canopy. These data are required to
improve the mapping and categorization of vegetation/biosphere, the monitoring
of change, and the parameterization in models of atmosphere-land surface
processes involving the exchange of heat, momentum, moisture, and gases.
The data will also contribute to distinguishing between deforestation and
Data from the Moderate
Resolution Imaging Spectroradiometer (MODIS) instrument on the EOS-AM satellite
will provide measurements of land and ocean surface temperatures, chlorophyll
fluorescence, and land surface vegetation — key elements of land and ocean
biology and ecosystems.
Ongoing data collection
from the Landsat satellites will provide continued monitoring and mapping
of land surface characteristics, vegetation, soils, and minerals.
The addition of several
coastal sites to the existing Long-Term Ecological Research (LTER) network
will provide data on the response of a broader distribution of ecosystems
to short- and long-term climate changes, as well as data on the response
to other stresses.
Chemistry of the Atmosphere
of the EOS Chemistry satellite, scheduled for launch in December 2002,
will provide: three-dimensional profiles on a global scale of all infrared
active trace gas species from the surface to the lower stratosphere and
measurements of greenhouse gas concentrations, tropospheric ozone, acid
rain precursors, and gas exchange leading to stratospheric ozone depletion.
Data will also be obtained on water vapor, aerosols, atmospheric temperature,
polar stratospheric clouds, and cloud tops.
of surface concentrations of ozone/UV radiation, and of CFCs and their
replacement compounds, halons, and other chemicals regulated under the
Montreal Protocol and its amendments, will be made by NOAA’s Climate Monitoring
and Diagnostics Laboratory network (a part of the ground-based Advanced
Global Atmospheric Gas Experiment).
Launch of the Total Ozone
Mapping Spectrometer (TOMS) will lead to continued measurements of atmospheric
Completion of the deployment
of ultraviolet radiation spectrophotometers will provide data from a UV
monitoring network at 14 national parks and 8 urban sites.
Improved technology to
delineate more accurately the timing of pre-historical climatic events
will provide data on the temporal and spatial character of natural climate
variability and abrupt climate changes during the period prior to significant
Establishment of a global
network of centuries-long paleoclimatic time series will help create links
to sedimentological, paleobiological, and geochemical data.
of paleoenvironmental data from North America will provide a clearer evaluation
of climate-induced vegetation and ecosystem change over the last 20,000
of Climate Change
Data from the ongoing
Landsat program will provide monitoring and categorization data on land
cover and land use, urban expansion, and agricultural practices.
Integration of climate
data with human health statistics will provide information on the occurrence
and spread of vector-borne diseases, heat-related mortality, and vulnerabilities
of social systems to climate variability and global change processes.
Measures of the health
effects of CFC replacement chemicals (HCFCs and halogenated hydrocarbons)
and UV radiation will provide information to decisionmakers.
LTER sites, which continue
to provide information on the response of ecosystems to changes due to
climate and other multiple stresses, will assist in distinguishing between
direct and indirect human-induced impacts.
The Global Water
from rainfall radar on board the Tropical Rainfall Measuring Mission (TRMM)
satellite, together with surface radars and rainfall stations, will provide
a benchmark for rainfall in the tropics. The data will be used to develop
a rainfall climatology, validate climate models, and demonstrate the impact
of rainfall in assimilation and weather forecast schemes. These data will
provide key information for the improved understanding, monitoring, and
modeling of the global water cycle, and assessment of water resources.
The North American Rain
Gauge Network will provide detailed information on the regional and local
impact of El Niño and climate change on rainfall, water supply,
and water resources.
Data collection from
the EOS-AM satellite will provide data on clouds and on the exchanges of
water and energy between the atmosphere, land, and oceans. These data will
also contribute to improved parameterizations in models of water/moisture
transports and budgets, improved weather forecasting, and the prediction
of the impacts of climate change on water resources.
Carbon Cycle Science
The operation of 25 AmeriFlux
sites, representing major ecosystem types in North and Central America
(including forests, croplands, grasslands, rangelands, and tundra), will
provide data for comparative (across ecosystem types) assessments of atmosphere/terrestrial-biosphere
exchanges of energy and water, net sequestration of carbon dioxide, and
the effects of environmental factors (including climate variations) on
the net exchange of carbon and the role of biophysical processes controlling
Landsat, MODIS, and VCL,
along with the Advanced Very High-Resolution Radiometer (AVHRR) will provide
improved global measurements of vegetation cover and changes, key components
in the carbon budget and carbon cycle of the Earth system. Ocean color
data from MODIS will include global ocean productivity maps at weekly time
intervals for assimilation into carbon cycle models.
Continued data collection
from SeaWifs will provide global and more accurate measures of ocean biology
and land surface vegetation, which are key elements in the global carbon
Data and information
management from these activities are critical to the success of the USGCRP,
supporting not only scientists but also a broader range of users including
teachers and educators, land use managers, and the public at large. Information
on the availability of data sets will be widely disseminated through the
Global Change Data and Information System (GCDIS). In FY 2000, the system
will provide the following data products to the broad range of users:
Integrated global data
sets from both research and operational space- and ground-based platforms
supporting all the research programs of the USGCRP.
El Niño monitoring
and prediction information.
Warning of natural hazards.
The analysis and assessment
ozone depletion and associated
greenhouse gas concentrations;
global and regional land
and ocean surface temperature;
global tropical precipitation;
global vegetation cover;
global ocean productivity;
global and regional carbon
sources and sinks;
global and regional ecosystems;
natural climate changes
of the past;
global and regional water
global change and vector
Over the longer term, USGCRP agencies are exploring ways to maintain the
long-term data records necessary for documenting and understanding global
change. NASA, NOAA, and DOD, the partners in the National Polar-orbiting
Operational Environmental Satellite System (NPOESS), are exploring ways
to extend the long-term measurements of key global change parameters beyond
the EOS AM-1 and PM-1 time frame to provide a bridge into the post-2008
NPOESS era. Internationally, the United States participates with other
nations in the Committee on Earth Observation Satellites, which has called
for developing an Integrated Global Observing Strategy (IGOS) to link space
and in-situ observations in a common strategic framework. The United States
also participates in the international coordination of the Global Climate
Observing System (GCOS), the Global Ocean Observing System (GOOS), and
the Global Terrestrial Observing System (GTOS). The broader objective of
IGOS is to develop a comprehensive strategy for integrated space-based
and in-situ observations to monitor the interactive Earth system holistically,
addressing the needs of scientific research and those of the broad community
of users involved in operational resource management, international assessments,
and policy development.