Gaining a Global Perspective: Linking GTOS and the LTER Network

Network News Spring 1998, Vol. 11 No. 1

James Gosz—Chair, LTER Network Coordinating Committee

In exciting new opportunity for interactivity and development of long-term research on a global scale has become available through the Global Terrestrial Observation System (GTOS) and the Global Terrestrial Network (GT-Net). The objectives of GT-Net and ILTER are complementary and an interaction would be beneficial to both.

Of prime interest to all countries is the participation in the GT-Net demonstration project involving the MODIS satellite imagery that will produce estimates of net primary production and net ecosystem production. Several LTER sites have been involved with this effort.

The MODIS demonstration project would provide site-specific data on;

  1. Vegetation cover
  2. Leaf Area Index
  3. Soils
  4. Climate
  5. Measurements of actual net primary production and flux measurements

to validate the imagery estimates of these factors.

It is recognized that not all international sites may be able to supply all of these data sets, especially in the developing regions.

The LTER Coordinating Committee recommended that the Network Office develop an outline for scientific and technological support to the GTOS Secretariat for work on terrestrial measurements and informatics, to be funded by the GTOS Secretariat.


Under the general direction of James Gosz, Chair of the GTOS Steering Committee, the U.S. Long Term Ecological Research (LTER) Network Office (NET) will provide work toward the development and implementation of a global network of terrestrial monitoring sites (GT-Net). The components described below will be integrated into ongoing International LTER (ILTER) research support activities at NET.

  1. Develop a web site for GT-Net at the ILTER Network Office in Albuquerque, New Mexico, in cooperation with the Secretariat in Rome. This web site will store and disseminate policies on data management, as well as dissemination and documentation of methods from among the members of GT-Net.
  2. Develop a GTOS metadata policy for the release and exchange of data related to terrestrial measurements in consultation with network and site participants 
  3. Develop, implement, and maintain a global database of metadata about the networks and sites participating in GT-Net, based on the TEMS database, and make the database available on the GT-Net web site described above. Updates and new entries would also be done via a web-interface. 
  4. Provide computer support for the assembly and exchange of data to facilitate the work of the GT-Net, as agreed on by a case by case basis. NET Office computer servers and analytical software will be made available as needed to support these efforts. The collaboration that the NET Office has with the San Diego SuperComputer Center would facilitate the assembly, storage and exchange of data. 
  5. Develop a personnel database and e-mail list for GT-Net that can be maintained, and searched via a web-based interface. 
  6. Support the implementation of demonstration projects and other GT-Net activities. The MODIS demonstration project is the first activity and NET will be responsible for reviewing existing data, collecting data from sites and providing software, imagery and help to sites that participate. This work will be based on work already completed for climate-related terrestrial measurements (TOPC). 
  7. Develop a mechanism for documenting the various methods used for measuring or calculating terrestrial variables. Make the mechanism available for use by the members of GT-Net as well as other terrestrial monitoring networks and sites. Develop and maintain a library of methods that are used by sites and networks and provide a reference list of these methods on the web; For key variables undertake efforts to harmonize measurement methodologies or other wise assure compatibility of data.

Development and implementation will be done with existing LTER Network staff under the direction of the Associate Director for Information Management, James W. Brunt, and the Associate Director for Technological Advancement, John Vande Castle.These components will be integrated along with GT-NET and ILTER activities, and will be supported on Network Office computer equipment. The web site and database will be produced in standard format that can be easily transferred to other computer equipment in other GT-Net locations.
The central mission of GTOS is to provide data for detecting, quantifying, locating and providing early warning of changes in the capacity of terrestrial ecosystems to sustain development and improvements in human welfare.

The Global Terrestrial Observing System (GTOS) was established in January 1996 by five co-sponsoring organizations:

  • United Nations Environment Program (UNEP)
  • Food and Agriculture Organization of the United Nations (FAO)
  • United Nations Educational, Scientific and Cultural Organization (UNESCO)
  • World Meteorological Organization (WMO)
  • International Council of Scientific Unions (ICSU)

Together with similar global observing systems for climate (GCOS) and the oceans (GOOS), GTOS has been created in response to international calls for a deeper understanding of global change in the Earth System.

To meet its objectives, GTOS will foster an integrated, equitable partnership of a wide variety of data providers and users that meets both the short-term development needs of national governments and the longer-term needs of the global change research community. High priority will be given to the needs of developing countries, which will be among GTOS’ most important data users.

GTOS is envisaged as a "partnership of partnerships", formed largely by linking existing monitoring sites and networks and present and planned satellite remote sensing systems. GTOS will provide the framework from which data from earth-observing satellites and environmental databases can be integrated with in situ observations.

More information about GTOS can be found at the website: