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CONTENTSReport of 1993 CEOS Plenary
CEOS/IGBP-DIS Pilot Project on Data Exchange---This page
High Resolution Data Coverage for CEOS/IGBP-DIS Pilot Project
CEOS Working Group on Data (WGD)
CEOS Working Group on Calibration and Validation (WGCV)
Introduction of CEOS Community Locator System (CCLS)
Report of 1993 CEOS Plenary (continued from page 1)
Requirements for Participation in CEOS
News Highlights
1994 CEOS Meeting Calendar
CEOS/IGBP-DIS Pilot Project on Data Exchange
S. I. Rasool
Director, International Geosphere-Biosphere Program-Data and Information
System (IGBP-DIS)
The CEOS/IGBP-DIS Pilot Project was initiated at the sixth CEOS Plenary in London in December 1992 (see article by Lisa Shaffer, CEOS Newsletter #1). The objective of this joint project is to assess the applicability of Data Exchange Principles in support of Global Change Research.
- One of the seven principles abopted at the sixth Plenary clearly enunciates
that:
"Non discriminatory access to satellite data by all users for global change/climate and environmental research and monitoring is essential. This should be achieved within the framework of the exchange and sharing mechanisms set up by CEOS members."
CEOS invited IGBP-DIS to propose a project for data use by IGBP core projects in which the applicability of this principle will be tested for Exchange of High Resolution data that also involves commercial considerations. This particularly concerns data for Landsat, SPOT, MOS, ERS and JERS. (The project has now been extended to include data from Indian Remote Sensing Satellite as well.)
Rapid progress in the development of this Pilot Project has been achieved during this last year. Both the space agencies concerned and the IGBP scientists seem most eager for this project to succeed.
At the request of CEOS, IGBP-DIS consolidated the data requirement of IGBP researchers into a document distributed in June 1993 (Scientific Rationale and Requirements for High Spatial Resolution Satellite Data in Support of the IGBP-S.I.Rasool-IGBP-DIS Office, Paris, France).
The specific objectives of the Pilot Project as envisaged by the IGBP researchers are:
1)to ascertain what data are available from existing high spatial resolution satellite systems for global change research projects within the IGBP.
2)to assemble datasets from existing archives for selected IGBP Core Projects.
3)to develop and implement a data acquisition model for acquiring new high resoltion data sets to support selected IGBP Core Projects.
4)to provide to the Global Change research community ready access to these data at the marginal cost of reproduction.
Consolidated Data Requirements
The scientific issues to be addressed by the availability of High Resolution
Data include:
*Climate and hydrological systems
-land/atmosphere: water and energy fluxes
-atmosphere/cryosphere interactions
*Biogeochemical dynamics
-biosphere/atmosphere fluxes of trace gases
-terrestrial biosphere nutrient and carbon cycling
*Ecological systems and dynamics:
-long term measurements of structure/function
-response to climate and other stresses
-interactions between physical and biological processes
Satellite observations provide precise, quantitative data for measurement
of deforestation and other forms of land cover conversion, and of monitoring
land cover change generally. With the increased spatial resolution available
from Landsat, SPOT, MOS, ERS, JERS and IRS, it is possible to precisely
map and measure land cover conversion or provide local test site data for
calibration and validation of coarse resolution data. For example, in the
studies of the global carbon cycle, although we know that most of the increase
in atmospheric carbon dioxide over the past thirty five years has been
due to fossil fuel combustion, yet as much as one third is derived from
land cover conversion. In fact over the last 200 years the total release
of carbon dioxide from land cover conversion has been approximately equal
to that from fossil fuels. However the precise amount is uncertain. Estimates
of the net flux of carbon from land cover change range from 0.4-2.5x10
15 gCyr-1. Three factors contribute to this uncertainty: (1)the rate of
deforestation, particularly in the tropics, (2) the fate of deforested
land (i.e. the amount of secondary forest regrowth and re-clearing) and
(3) the stock of biomass and soil organic matter and the response of these
pools to disturbance. The first two uncertainties are of critical importance
and could best be resolved with high resolution satellite data.
These same measurements on land cover conversion affects the fluxes
of trace gases such as N2O, CH4, CO and O3 and help in improving estimates
of the sources and sinks of the gases.
A second kind of study carried out by IGBP which requires High Resolution
Data is the one which is performed along a transect of thousand kilometers
or more of varying climate and/or ecosystem. For example, the North Australian
Tropical Transect (NATT) is a research program whose objectives are to
determine the effects of soil and climatic variability, land management
and global climate change on the savannas of Northern Australia. It extends
from Darwin to Alice Springs.
NATT makes use of the pattern of decreasing mean annual rainfall with
increasing distance from the north coast of the Northern Territory. By
conducting studies at varying levels of rainfall, a better understanding
can be gained of ecological processes on a continental scale. A similar
transect study is being conducted in west Africa and by comparing results
from the two studies, the effects of vastly different human pressures will
be seen.
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