GOSIC Banner
 
Facilitating Access to Global Observing Systems Data and Information

GCOS Essential Climate Variables (ECV)
Data Access Matrix

The Essential Climate Variables (ECV) are required to support the work of the United Nations Framework Convention on Climate Change (UNFCCC) and the Intergovernmental Panel on Climate Change (IPCC). All ECV are technically and economically feasible for systematic observation. It is these variables for which international exchange is required for both current and historical observations. Additional variables required for research purposes are not included in this table. It is emphasized that the ordering within the table is simply for convenience and is not an indicator of relative priority. Currently, there are 44 ECVs plus soil moisture recognized as an emerging ECV. More About the ECV Matrix

August 2010 - Update of the ECV Matrix: The list of ECVs is evolving slowly as scientific requirements change and as technological developments permit. The updated list of ECVs now includes soil moisture, soil carbon, and ocean oxygen content and recognises the role of precursors in forming ozone and aerosols. Additionally, for clarity, some variables have been given a different name: 'ice sheets' were previously included in 'glaciers and ice caps' in the IP-04, and 'ocean acidity' and 'carbon dioxide partial pressure,' whose measurement allows characterisation of ocean carbon content, replace the 'ocean carbon' ECV in the IP-04. Actions in the Plan related to emerging ECVs, such as soil carbon, are more limited in what is expected to be achiedved in the next five years. (from the 'Implementation Plan for the Global Observing System for Climate in Support of the UNFCCC' August 2010, GCOS-138 (GTOS-184, GTOS-76, WMO-TD/No. 1523) (page 19) (pdf). New or modified ECVs are marked with a * below.

[About the ECV Matrix] [Reference Documents & Web Sites] [Contact] [ Lastest update September 1, 2010 ]
ATMOSPHERIC (over Land, Sea & Ice) OCEANIC TERRESTRIAL [2]
Surface [4]
Surface [6]
 River Discharge (ECV T1)
Pressure Carbon Dioxide Partial Pressure Water Use (ECV T2)
Air Temperature Current Ground Water (ECV T3)
Precipitation Ocean Acidity * Lakes (ECV T4) *
Surface Radiation Budget Ocean Color (for Biological Activity) Snow Cover (ECV T5)
Water Vapor Phytoplankton * Glacier and Ice Caps (ECV T6) *
Wind Speed and Direction Sea Ice Permafrost (ECV T7)
Upper-Air [5]
 Sea Level Albedo (ECV T8) *
Cloud Properties Sea State Land Cover (including Vegetation Type) (ECV T9)
Earth Radiation Budget (including Solar Irradiance) * Sea Surface Salinity (SSS) Fraction of Absorbed Photosynthetically Active Radiation (FAPAR) (ECV T10)
Temperature Sea Surface Temperature (SST) Leaf Area Index (LAI) (ECV T11)
Water Vapor
Sub-Surface
 Above ground Biomass (ECV T12) *
Wind Speed and Direction Carbon Dioxide Partial Pressure Fire Disturbance (ECV T13)
Composition
Current Soil Moisture *
Carbon Dioxide Nutrients Soil Carbon *
Methane Ocean Acidity * Ice Sheets *
Other Long-Lived Green House Gases [1] Oxygen *  
Ozone and Aerosols, supported by their precursors [3] * Salinity  
Temperature  
  Tracers  

* Added or modified per 'Implementation Plan for the Global Observing System for Climate in Support of the UNFCCC' August 2010, GCOS-138 (GTOS-184, GTOS-76, WMO-TD/No. 1523) (page 19) (pdf)

[1] The 'Other long-lived greenhouse gases' ECV includes Nitrous Oxide (N2O), Chlorofluorocarbons (CFCs), Hydrochlorofluorocarbons (HCFCs), Hydrofluorocarbons (HFCs), Sulphur hexafluoride (SF6), and Perfluorocarbons (PFCs).
[2] Includes Runoff (m3 s-1), Ground Water Extraction Rates (m3 yr-1) and Location, Snow Cover Extent (km2) and Duration, Snow Depth (cm), Glacier/Ice Cap Inventory and Mass Balance (kg m-2 yr-1), Glacier Length (m), Ice Sheet Mass Balance (kg m-2 yr-1) and Extent (km2), Permafrost Extent (km2), Temperature Profiles and Active Layer Thickness, above ground Biomass (t/ha), Burnt Area (ha), Date and Location of Active Fire, Burn Efficiency (% Vegetation Burned/Unit Area)
[3] NO2, SO2, HCHO, CO
[4] including measurements at standardized but globally varying height in close proximity to the surface
[5] Up to the stratopause
[6] Including measurements with the surface mixed layer, usually with the upper 15 meters