Summer hydrography on the shelf off Terre AdeŽlie/George V Land based on the ALBION and CEAMARC observations during the IPY
Lacarra, M and Houssais, M and Sultan, E and Rintoul, SR and Herbaut, C, Summer hydrography on the shelf off Terre Ade lie/George V Land based on the ALBION and CEAMARC observations during the IPY, Polar Science, 5, (2) pp. 88-103. ISSN 1873-9652 (2011) [Refereed Article]
We report on the hydrographic observations collected on the Antarctic continental shelf between 138E and 146E as part of the
CEAMARC and ALBION projects in December 2007eJanuary 2008. A total of 140 quasi-synoptic CTD (ConductivityeTemperatureeDepth)
casts were analysed to map the spatial distribution of the summer hydrographic properties. Seven
distinct hydrographic regimes were identified based on regional topographic features and the presence of specific water masses.
These regimes are associated with spatial contrasts in the distribution of the High Salinity Shelf Water (HSSW) and the Modified
Circumpolar Deep Water (MCDW). In particular, the HSSW distribution confirms the unique character of Commonwealth Bay in
terms of extreme bottom salinity and dissolved oxygen values. The bay appears to be a preferred region for both dense shelf water
formation and storage. The systematic survey of the AdeŽlie Depression shows the ubiquitous presence of HSSW in the depression,
and over the AdeŽlie Sill as a 60 m thick layer at the centre of the sill. This water is dense enough to mix down the continental slope
and form Antarctic Bottom Water. Upstream of the sill, the HSSW is shown to sit over the topography with indications of recirculation.
The DUrville Trough, another deep basin on the shelf, is filled with warmer and fresher water that is too light to contribute
to the formation of AABW. The DUrville Trough appears to collect MCDW which enters at the shelf break over the AdeŽlie Bank
and spreads over the northern slope of the trough. Another branch of MCDWenters in the eastern AdeŽlie Sill and is found almost
everywhere in the AdeŽlie Depression with the noticeable exception of the coastal bays. Additional CTD casts collected during the
ALBION-2009 experiment in January 2009 suggest that most of the features observed in 2008 in the AdeŽlie Depression should be
robust on a year-to-year basis although summer 2009 was characterized by fresher dense shelf waters.
2011 Elsevier B.V. and NIPR. All rights reserved.
Antarctica; Shelf water masses; AdeŽlie land; Polynya