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| Titel |
Antarctic Bottom Water from the Adélie and George V Land coast, East Antarctica (140-149âE) |
| VerfasserIn |
Guy Williams, Shigeru Aoki, Stan Jacobs, Stephen Rintoul, Takeshi Tamura, Nathan Bindoff |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250037728
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| Zusammenfassung |
| Abstract
We report on observations of dense shelf water overflows and Antarctic Bottom
Water (AABW) formation along the continental margin of the Adélie and George
V Land coast between 140–149-E. Vertical sections and bottom layer water
mass properties sampled during two RVIB Nathaniel B Palmer hydrographic
surveys (NBP00–08, Dec. 2000/Jan. 2001 and NBP04–08, Oct. 2004) describe the
spreading of cold, dense shelf water on the continental slope and rise from two
independent source regions. The primary source region is the Adélie Depression,
exporting high salinity shelf water through the Adélie Sill at 143-E. An additional
eastern source region of lower salinity dense shelf water from the Mertz Depression
is identified for the first time from bottom layer properties north-west of the
Mertz Sill and Mertz Bank (146–148-E) that extend as far as the Buffon Channel
(144.75-E) in summer. In spring the modified shelf water on the slope is colder (<
-0.9-C) and there is eddy-like features that interrupt the Antarctic Slope Front over
the continental slope west of 145-E that are possibly the result of cascade-induced
upwelling close to the peak export season. Regional analysis of satellite derived
ice production estimates over the entire region from 1992–2005 suggests that the
Mertz Depression contributes up to 40% of the total ice production and is therefore
likely to make a significant contribution to the total dense shelf water export from
this region. Concurrent time-series from bottom mounted Microcats and ADCP
instruments from the Mertz Polynya Experiment (April 1998–May 1999) near the
Adélie Sill, and on the upper continental slope (1150m) and lower continental rise
(3250m) to the north describe the seasonal variability in downslope events and
their interaction with the ambient water masses. At the upper slope, cold dense
events correlate strongly with increased speed as the warm, saline Antarctic Slope
Front oscillates north-south with predominantly diurnal tides. On the continental
rise, in the vicinity of the Jussieu Channel and Channel ’G’ north of the Adélie
Sill, weekly cold ( |
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