Oceanography Seminar

Speaker: John Bullister
Associate Professor
Chemical Oceanography
Pacific Marine Environmental
Laboratory/NOAA

"Dissolved Chlorofluorocarbons and Sulfur Hexafluoride as Transient Tracers in the Ocean"

Abstract:

Significant release of chlorofluorocarbons (CFCs) into the atmosphere began in the 1940s and atmospheric concentrations of these anthropogenic compounds increased rapidly during the following decades. Atmospheric CFCs dissolve in surface seawater and are carried into the interior of the ocean where they act as passive tracers of ocean circulation and mixing processes. Measured inventories of dissolved CFCs have been used in studies to obtain independent estimates of the formation rates of key water masses and changes in these rates of formation on decadal timescales. CFC can be used to estimate the rates of key biogeochemical processes in the ocean and have been especially useful in helping to improve estimates of anthropogenic CO2 uptake in the ocean. While the rates of increase of CFCs in the atmosphere have slowed in the past decade, sulfur hexafluoride (SF6) levels in the atmosphere have continued to increase rapidly, making this anthropogenic compound an especially valuable new transient tracer of recently ventilated waters. Simultaneous measurements of dissolved SF6 along with CFCs can provide additional information over the use of each tracer alone.

Thursday November 12, 2009 3:00 p.m. MSB 100

Ticket Information
FREE

Event Sponsor
Oceanography, Manoa Campus

More Information
808-956-7633, ocean@soest.hawaii.edu, http://www.soest.hawaii.edu/oceanography/seminar.html

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