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Oceanography Brown Bag Seminar
The age distribution of the ocean and implications for
the uptake of anthropogenic CO2
Synte completed her Ph.D. at the Lamont-Doherty Geophysical Observatory,
part of Columbia University, and concentrated in geology for her
undergraduate studies at Oxford University in England. In March of 2000
Synte did part of her graduate research in oceanography aboard the Nathaniel
B. Palmer in
Antarctica. Synte completed her postdoc position at the Center for
Nonlinear Studies, Los
Alamos National Laboratory, then came to the University of Chicago.
ABSTRACT
Results will be presented from a 2000-year global ocean simulation
which carried 21 tracers, including global and regional 'transit-time
distributions', chlorofluorocarbons, natural and anthropogenic carbon, and
ideal age. The 'true mean age' of the model is everywhere surprisingly
large, due to very long-tailed probability density functions. Certain
regions of the ocean exhibit multiple arrivals, leading to multi-modal
pdfs. The regions characterized by such behavior will be highlighted, and
the causes diagnosed. Results from the regional transit-time distribution
simulations will also be presented, and the information these tracers
yield which is not captured by the global transit-time distribution will
be discussed.
It has been recently demonstrated in a simple box model
framework that the full age distribution can lead to much more accurate
estimates of the amount of anthropogenic carbon in the ocean than the
traditional 'CFC-age'-based methods. However, such estimates rely on the
predictability of the functional form of the pdf. The accuracy to which the
pdfs can be described by two free parameters is explored based on the ocean
model results, and the potential for predictability of the pdfs based on
ocean data is investigated. The model results allow a direct assessment of
the bias in currently existing estimates of anthropogenic CO2 in the ocean
based on CFC-ages rather than the full age distribution.
For more information, contact:
Lisa Butler.
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