WOCE (World Ocean Circulation Experiment; for information check the WOCE Home Page)
The main goals of the World Ocean Circulation Experiment (WOCE) are (1) to develop models that are capable of describing the present state of the ocean and to predict its evolution in relation to long-term climate changes, and (2) to collect the data required for the development and calibration of such models (WCRP. 1986). The measurements required for a successful WOCE were summarized in the WOCE Implementation Plan (Volumes I and II; WCRP, 1988).
Among many components they include the collection of tracer data as part of the WOCE Hydrographic Program (WHP). The WOCE tracer data set consists mainly of the transient tracers CFCs (Chlorofluorocarbons CFC 11 and CFC12), tritium, tritiogenic 3He, CFCs and bomb 14C, as well as the 'steady-state' tracers 3He, 4He and stable isotopes of water.
Due to the nature of their delivery to the ocean, the transient tracers are a close analogue to any perturbation imprinted onto the surface of the ocean such as a climate signal. They can be viewed as a gigantic dye experiment that allows us to visualize the penetration of this perturbation into the interior of the ocean, as well as to determine the time scale on which it occurs. The 'steady-state' tracers, on the other hand provide information on the averaged spreading patterns of waters tagged with tracer at specific source locations (e.g., the mid-ocean ridges for 3He or glacial ice for 4He). Such information is important for understanding the basic dynamics of the ocean, as well as for calibration of ocean circulation models.
During the WOCE survey, samples for measurement of tritium and helium isotopes were collected on most WHP sections. This site is intended to provide an overview of the WOCE tritium/helium isotope survey and the developing results. The site contains information on: