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Purpose of the GSN

The GCOS Surface Network (GSN) is a global network of over 1000 stations selected from the network of many thousands of existing meteorological stations. The GSN is intended to comprise the best possible set of land stations with a spacing of 2.5 to 5 degrees of latitude, thereby allowing coarse-mesh horizontal analyses for some basic parameters (primarily Temperature and Precipitation). The criteria for selection include:

It is recognized that the coarse network density limits the applicability for some applications. For parameters having smaller-scale horizontal variability (e.g., precipitation), it is accepted that the network data generally should be supplemented by those from networks with a finer mesh.

In particular, GCOS and its surface component serve to support the work of Intergovernmental Panel on Climate Change (IPCC), and the implementation of the UN Framework Convention on Climate Change (FCCC).

Monitoring Climate Variability

Observations of climate parameters at or near the earth's surface comprise a crucial part of GCOS. It is at the earth's surface that human beings live. It is the interface between the atmosphere and the underlying components of the climate system: land, ocean, cryosphere and biosphere. The climate at the earth's surface, the surface temperature in particular, is considered to be essential for monitoring climate variability and detecting anthropogenic climate change. It is therefore essential that GCOS provide the data sets to support the scientific and operational aspects of the climate at the earth's surface.

The GCOS surface climate data are a component of the overall Global Climate Observing System, and, as such, serve the overall GCOS purposes and users.

Purposes of the GSN

  • To establish national commitments for the preservation of a set of valuable climate stations for the foreseeable future;
  • To build a collection of validated data from these stations in standardized formats;
  • To provide this information to the global climate community with no formal restrictions;
  • To create a baseline and benchmark data set for more enhanced regional and sub regional climate networks and for newly-developed observing systems, including remote-sensing systems.