Southern Ocean Dynamics A Strategy for Scientific Exploration, 1973-1983 (1974) / Chapter Skim
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EXCHANGE PROCESSES AND OVERALL BUDGETS
EXCHANGE PROCESSES AND OVERALL BUDGETS
Pages 37-51
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From page 37... ...
Estimation of fluxes occurring within gyres and near continental margins to assess the interaction of Antarctic Surface Water south of the Antarctic Circumpolar Current with warmer, saltier deep water.
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From page 38... ...
The divergent wind drift and intense thermohaline alterations of the surface waters around Antarctica set up a meridional circulation pattern that carries great quantities of heat, salt, and water from the northern abyssal waters into the Southern Ocean. This water upwells and is altered to cold antarctic water masses, which subsequently spread northward.
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From page 39... ...
The antarctic convection pattern extends by lateral migration below the main thermocline of the world ocean. The northward flow of AABW occurs mainly in deep western boundary flows, and the AAIW represents a layer separating the thermocline waters from the abyssal waters.
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From page 40... ...
The water composing the two antarctic water masses eventually flows back to the south in each ocean, with important additions of relatively salty but warmer water from the North Atlantic Ocean. The North Atlantic Deep Water (NADW)
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From page 41... ...
By assuming that the 60 x 106 m3/s of deep-water upwelling continues at this rate all year, that the low-salinity water lost at the Polar Front removes excess surface water but not salt from the surface layer, and that the average salinity of the sinking cold saline shelf water is 34.65°/0o, it is possible to construct an annual salt balance of the surface water [Gordon and Taylor, 1973]
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From page 42... ...
Figure 5.2 shows in schematic fashion the average circumpolar meridional volume flux obtained from the foregoing estimates of heat and salt budgets. The 10 x 106 m3/s value for returning AAIW is determined here from conservation of mass, and the 60 x 106 m3/s of deep water passing southward below the Polar Front Zone is also approximate.
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From page 43... ...
of the Polar Front at various positions and times so that a determination can be made of its importance relative to other frontal areas in exchange processes. Other frontal zones exist about which little is known.
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From page 44... ...
. FIGURE 5.3 Double polar front structure often observed in the thermal structure in the Pacific sector [Gordon, 1971a]
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From page 45... ...
The extensive ice cover of Antarctica is further augmented by the highly important waxing and waning of the effective edge of the continent due to sea-ice fluctuations. Records of antarctic sea ice indicate two crucial phenomena: the first is the very large year-to-year variation in ice cover, over which are superimposed the strong seasonal oscillations; the second is the extensive ice-free regions that form near the continent early in the melting season, or possibly throughout the entire year, and that separate the openocean sea ice from near-coastal sea and glacial ice.
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From page 46... ...
We know little of the meridional and vertical transfer of heat in the antarctic region, especially below the sea-ice and glacial-ice covers; the thermohaline "history" of subice water column for growing and melting ice cover is thus of primary importance to budget studies and understanding of the sea-ice fluctuations. Sea ice also influences the haline component of the water column.
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From page 47... ...
6. Meteorology The presence of a permanent continental ice cap reaching to the edges of the Antarctic continent allows the polar high-pressure area to extend over the continental margins of Antarctica, producing in the coastal region a general easterly airflow that is often marked by strong katabatic winds.
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From page 48... ...
Such measurements can be used to monitor the near-surface heat storage, to refine the sea-air heat flux, and, by observing drift of the buoys or by measuring the current from the moored systems, to determine the response of the ocean to the wind. Subsurface moored buoys can be used to obtain long-term thermohaline and current measurements below the sea ice.
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From page 49... ...
Exchange Processes and Overall Budgets Experiments and Goals Proposed Experiments and Theory Monitoring Experiments * Ice cover variability from microwave imagery from satellites.
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From page 50... ...
Begin 1 Survey • Collect planning data across frontal zones • Detailed frontal survey • Collect supply and weather ship data [Theory • Refine existing budgets with new and incoming data • Use input from other experiments to formulate Southern Ocean models • Review and formulate adequate frontal zone models Begin Begin Begin Begin "Begin Begin Begin Establish monitoring for FGGE collaboration Merge into Internationl Climate Research Effort REFERENCES Burling, R
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From page 51... ...
1961. The Antarctic Circumpolar Current and the Antarctic Polar Front.
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