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The concept of Global Terrestrial Networks (GTNs)

General Introduction

The mission of the Global Climate Observing System (GCOS) is that all users have access to climate observations, data records and information that they require to address pressing climate-related concerns. GCOS users include individuals, national and international organizations, institutions and agencies. The role of GCOS is to ensure the sustained provision and availability of reliable physical, chemical and biological observations and data records for the total climate system – across the atmospheric, oceanic and terrestrial domains, including hydrological and carbon cycles and the cryosphere. GCOS has identified 50 Essential Climate Variables (ECVs) considered to be feasible for global climate observation. There is a strong need for sustained observation of those ECVs, as they can help to make significant progress in the generation of global climate products and derived information.

Global Terrestrial Networks (GTNs) contribute the observation of terrestrial ECVs by combining space-based satellite observations, field measurements and the development of global models for the purpose of operating a strong monitoring network that can provide a consistent and long-term data series of selected terrestrial parameters. It is the networks’ goal to assess those different parameters/ECVs states and changes, and to develop suitable guidelines and protocols for observing standards and future data reporting. The GTNs are important in developing the capacity and support to gather the required global data on the following GCOS terrestrial ECVs, which were identified in the GCOS Implementation Plan for the Global Observing System for Climate in support of the United Nations Framework Convention on Climate Change (UNFCCC): River Discharge, Water Use, Ground Water, Lake and Reservoir Levels and Volumes, Soil Moisture, Snow Cover, Glaciers and Ice Caps, Ice Sheets, Permafrost, Land Surface Albedo, Land Cover, Fraction of absorbed photosynthetically active radiation (FAPAR), Leaf Area Index, Above ground Biomass, Fire Disturbance, and Soil Carbon. 

The following GTNs are contributing to GCOS:

Name of Network
Additional information
Areas of particular focus
GTN-related ECVs
Data information

Global Terrestrial Network for Glaciers (GTN-G)

 

Climate Change - Human Settlements - Land Resources - Sustainable Development - Global Sea Level Rise - Water Resources - Natural Hazards

Snow Cover, Glaciers and Ice Caps, Ice Sheets, (Sea Level)

On global scale; regularly updated information on glacier distribution and changes; fluctuations database at WGMS with > 3,500 glaciers since 19th century; inventory database at NSIDC with > 100,000 glaciers from mid 20th and early 21st centuries

Global Terrestrial Network for Hydrology (GTN-H)

 

Agriculture - Biodiversity - Climate Change - Desertification - Forests - Health - Human Settlements - Land Resources - Sustainable Development - Water and Sanitation

Precipitation, Water Vapour, River Discharge, Ground Water, Water Use, Lakes, Glaciers and Ice Caps, Soil Moisture

On global and regional scale (national monitoring programmes, science programmes); data from 1900 onwards (single variables, discontinuous)

Global Terrestrial Network for Lakes (GTN-L)

Sub-network of the Global Terrestrial Network for Hydrology (GTN-H)

Biodiversity - Climate Change - Human Settlements - Land Resources - Sustainable Development

Lakes (Lake Level, Lake Area, Water Temperature, Ice Thickness)

Mainly on regional basis (> 600 water level reference stations); monthly and annual data input

Global Terrestrial Network for Permafrost (GTN-P)

 

Biodiversity - Climate Change - Human Settlements - Land Resources - Sustainable Development

Permafrost, (Ice Sheets, Snow Cover)

Mainly on regional and national basis (80-site network under IPA's Circumpolar Active Layer Monitoring (CALM); inventory and metadata for > 200 boreholes of varying depths)

Global Terrestrial Network for Rivers (GTN-R)

Sub-network of the Global Terrestrial Network for Hydrology (GTN-H)

Agriculture - Climate Change - Desertification - Health - Human Settlements - Land Resources - Sustainable Development - Water and Sanitation

River Discharge, (Water Use, Lakes, Soil Moisture)

Mainly on regional basis (> 450 river discharge reference stations); daily data input; highly dependent on data provided by National Hydrological Services (NHS)

* For more information about each GTN, please follow the links provided in the table. 

 

 




Last modified on Fri, 04 Oct 2013