Award: OCE-2048995

Project Outcomes for the measurement of tracers on the GEOTRACES GP17 research cruise

This research project measured the dissolved concentrations of the man-made gases CFC-11, CFC-12 and Sulfur hexafluoride (SF₆) in samples collected on the GP-17 cruise. These gases have been found in the atmosphere since the 1940’s for the CFCs and 1970’s for SF₆. The atmospheric concentrations have been changing with time. Small amounts of these gases dissolve in the surface water of the oceans and are analogous to putting a colored dye into the surface water. We can then watch these “dyes” spread into the intermediate and deep oceans and gain information on the patterns and time scales of intermediate and deep ocean circulation. Since ocean circulation plays a big role in regulating the earth’s climate, any technique that helps determine circulation patterns and time scales is very useful. Using the ratio of SF₆/CFC-12 we can determine when the water sample was last in contact with the atmosphere. This is typically referred to as the “age” of the water. Trace element distribution in the ocean is the main focus for the GEOTRACES program, and this age information is very useful in determining the rates of reactions of the trace elements of interest (TEIs)

Last Modified: 07/29/2025
Modified by: James D Happell