Chlorofluorocarbon distributions in the deep Argentine Basin

Conference · Tue Jan 09 00:00:00 EST 1990 · EOS, Transactions, American Geophysical Union; (United States)

OSTI ID:6880776

Warner, M J ^[1]; Weiss, R F ^[2]; Smethie, Jr, W M ^[3]

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1. Univ. of Washington, Seattle (United States)
2. Univ. of California-San Diego, La Jolla (United States)
3. Columbia Univ., Palisades, NY (United States)

The seawater concentrations of the chlorofluorocarbons (CFCs) F-11 and F-12 were measured in the Argentine Basin during the Abyssal Boundary Current Studies (1986) and the South Atlantic Ventilation Experiment (1988-89) expeditions. In most regions of the basin, the CFC concentrations are above the detection limit (0.015 pmol/kg) in the entire water column. The main features of the F-11 and F-12 profiles in the deep waters of the Argentine Basin are concentration mixima at depths of 2 to 3 km and generally increasing concentrations towards the bottom. The mid-depth CFC minima are associated with the salinity maximum of Circumpolar Deep Water (CDW). The higher CFC concentrations at the seafloor are correlated with the colder temperatures of Antarctic Bottom Water (AABW). The CFC concentrations in AABW are highest on the eastern portion of the basin along 47[degrees]S and along the southern and western boundaries. These distributions are consistent with a separation of the inflowing AABW into a cyclonic gyre in the eastern portion of the basin and a western boundary current which carries a detectable CFC singal as far noth as 17[degrees]S. Between CDW and AABW, there are local CFC maxima and minima which are not associated with extrema in other hydrographic properties. The local minima are found on a mean density of 46.07 [sigma][sub 4], which is the upper bound of the water entering the Argentine Basin from the Weddell Sea (Reid, Deep-Sea Res., 1989 submitted). The local CFC maxima are found at about the 46.00 [sigma][sub 4] isopycnal surface. Water of this density apparently is of circumpolar origin. The presence of these local CFC extrema in this density range carries information on the time-dependent vertical mixing in the deep Argentine Basin.

• OSTI ID: 6880776
• Report Number(s): CONF-9002174-; CODEN: EOSTAJ
• Journal Information: EOS, Transactions, American Geophysical Union; (United States), Vol. 71:2; Conference: Ocean sciences meeting, New Orleans, LA (United States), 12-16 Feb 1990; ISSN 0096-3941
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
CHLOROFLUOROCARBONS
ECOLOGICAL CONCENTRATION
POLLUTANTS
DISTRIBUTION
SEAWATER
SALINITY
WATER POLLUTION
DENSITY
MIXING
WEDDELL SEA
ATLANTIC OCEAN
HYDROGEN COMPOUNDS
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC FLUORINE COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
POLLUTION
SEAS
SURFACE WATERS
WATER
540320* - Environment
Aquatic- Chemicals Monitoring & Transport- (1990-)