| 1. |
- Kitade, Yujiro, et al.
(författare)
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Antarctic Bottom Water production from the Vincennes Bay Polynya, East Antarctica
- 2014
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Ingår i: Geophysical Research Letters. - 0094-8276 .- 1944-8007. ; 41:10, s. 3528-3534
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Tidskriftsartikel (refereegranskat)abstract
- One year moorings at depths greater than 3000m on the continental slope off Vincennes Bay, East Antarctica, reveal the cold (<-0.5 degrees C) and fresh (<34.64) signals of newly formed Antarctic Bottom Water (AABW). The signal appeared in June, 3 months after the onset of active sea-ice production in the nearby Vincennes Bay Polynya (VBP). The AABW signal continued for about 5 months at two moorings, with 1 month delay at the western site further downstream. Ship-based hydrographic data are in agreement, detecting the westward spread of new AABW over the continental slope from VBP. On the continental shelf, Dense Shelf Water (DSW) formation is observed by instrumented seals, in and around the VBP during autumn, and we estimate its transport to be 0.16 +/- 0.07 (x 106m3s-1). We conclude that the DSW formed in this region, albeit from a modest amount of sea-ice production, nonetheless contributes to the upper layer of AABW in Australian-Antarctic Basin.
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| 2. |
- Ohshima, Kay I., et al.
(författare)
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Antarctic BottomWater production by intense sea-ice formation in the Cape Darnley polynya
- 2013
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Ingår i: Nature Geoscience. - 1752-0894 .- 1752-0908. ; 6:3, s. 235-240
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Tidskriftsartikel (refereegranskat)abstract
- The formation of Antarctic Bottom Water-the cold, dense water that occupies the abyssal layer of the global ocean-is a key process in global ocean circulation. This water mass is formed as dense shelf water sinks to depth. Three regions around Antarctica where this process takes place have been previously documented. The presence of another source has been identified in hydrographic and tracer data, although the site of formation is not well constrained. Here we document the formation of dense shelf water in the Cape Darnley polynya (65 degrees -69 degrees E) and its subsequent transformation into bottom water using data from moorings and instrumented elephant seals (Mirounga leonina). Unlike the previously identified sources of Antarctic Bottom Water, which require the presence of an ice shelf or a large storage volume, bottom water production at the Cape Darnley polynya is driven primarily by the flux of salt released by sea-ice formation. We estimate that about 0.3-0.7 x 10(6) m(3) s(-1) of dense shelf water produced by the Cape Darnley polynya is transformed into Antarctic BottomWater. The transformation of this water mass, which we term Cape Darnley BottomWater, accounts for 6-13% of the circumpolar total.
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