Transient Tracers

Blue ocean background featuring a banner titled "Transient Tracers: Essential Climate Variable (ECV) Factsheet" with logos of related organizations at the bottom.
Transient tracers are man-made chemical compounds released to the atmosphere at known quantities that can be used in the ocean to quantify ventilation, transit time distribution and transport time-scales. Measurement of transient tracers in the subsurface ocean thus provides information on the time-scales since the ocean was ventilated, i.e. in contact with the atmosphere. A combination of these tracers provide the means to constrain the transit time distribution (TTD) of a water-mass that allows inference of concentrations or fates of other transient compounds, such as anthropogenic carbon or nitrous oxide.

ECV Products and Requirements

These products and requirements reflect the Implementation Plan 2022 (GCOS-244).

The requirements are found in the complete 2022 ECVs Requirements document as well: ECV Transient Tracers.

Products 14CSF₆  CFC-11CFC-12
RegionalDeep water formation areasRegionalDeep water formation areas RegionalDeep water formation areasRegionalDeep water formation areas
 (*)UnitValuesValues UnitValuesValues
Horizontal ResolutionGkm20002002000200 km20002002000200
B     
T20002000 20002000
Vertical ResolutionG --  --
B-- --
T-- --
Temporal ResolutionGy102102 y102102
B     
T1010 1010
TimelinessGy11 month66
B     
T22 66
Required Measurement Uncertainty (2-sigma)G‰10.4 ‰11
B     
T2    
StabilityG decadal1ydecadal1y  decadal1ydecadal1y
B     
Tdecadaldecadal decadaldecadal

(*) Goal (G): an ideal requirement above which further improvements are not necessary. Breakthrough (B): an intermediate level between threshold and goal which, if achieved, would result in a significant improvement for the targeted application. The breakthrough value may also indicate the level at which specified uses within climate monitoring become possible. It may be appropriate to have different breakthrough values for different uses. Threshold (T): the minimum requirement to be met to ensure that data are useful

Data sources

This list provides sources for openly accessible data sets with worldwide coverage for which metadata is available. It is curated by the respective GCOS ECV Steward(s). The list does not claim to be complete. Anyone with a suitable dataset who wishes it to be added to this list should contact the abombelliatwmo [dot] int (GCOS Secretariat).

  • Global Ocean Data Analysis Project (GLODAPv2)
  • CLIVAR and Carbon Hydrographic Data Office (CCHDO)
  • National Centers for Environmental Information Ocean Carbon Data System (NCEI OCADS)
  • PANGAEA
Transient tracers
Домен:
Ocean
Subdomain:
Biogeochemical
Scientific Area:
Carbon Cycle and other GHGs
ECV Steward:
Products:
14C; SF₆; CFC-11; CFC-12