HR: 17:15h
AN: OS24B-06    [Abstracts]
TI: Temporal evolution of the CFC distributions along the SR3 section between Tasmania and Antarctica
AU: * Warner, M J
EM: warner@u.washington.edu
AF: University of Washington, School of Oceanography Box 355351, Seattle, WA 98195-5351 United States
AU: Bullister, J L
EM: john.l.bullister@noaa.gov
AF: NOAA - Pacific Marine Environmental Laboratory, 7600 Sand Point Way NE, Seattle, WA 98115-6349 United States
AU: Rintoul, S R
EM: steve.rintoul@csiro.au
AF: CSIRO Marine Research, GPO Box 1538, Hobart, TAS 7001 Australia
AU: Tilbrook, B
EM: bronte.tilbrook@csiro.au
AF: CSIRO Marine Research, GPO Box 1538, Hobart, TAS 7001 Australia
AU: Sabine, C L
EM: chris.sabine@noaa.gov
AF: NOAA - Pacific Marine Environmental Laboratory, 7600 Sand Point Way NE, Seattle, WA 98115-6349 United States
AB: The dissolved CFCs were measured as part of a 2001 Australian CLIVAR repeat hydrography expedition between Tasmania and Antarctica on the SR3 section. The CFCs were measured along this section previously in 1991 and 1995, providing an opportunity for determining the penetration of these transient tracers into the water column in this region of the Southern Ocean. The largest changes in CFC concentrations are in the Adelie Land Bottom Water and in the waters with neutral density less than 27.7. The CFC concentrations within Circumpolar Deep Waters are only slightly changed over the 10 years except adjacent to the Antarctic continental slope. When pCFC values are compared on isopycnal surfaces, the waters within the pycnocline between the Subantarctic Front and the southern expression of the Polar Front are less ventilated in 2001 than in previous occupations. Changes in AOU and DIC concentrations are consistent with the changes in pCFC ages within this feature. These changes in properties appear to be the result of a much weaker temperature minimum accompanied by an expansion of the underlying temperature maximum waters. The changes in the CFC concentrations in ALBW provide limits for the calculation of bottom water formation in the Southern Ocean. CFC saturations relative to equilibrium with the atmosphere vary between 30% and 42% in the recently ventilated bottom water. The relationship between CFCs and DIC in these waters will also be examined.
DE: 4808 Chemical tracers
DE: 4207 Arctic and Antarctic oceanography
DE: 4283 Water masses
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting