A seasonal cycle in the export of bottom water from the Weddell Sea.

Gordon, Arnold L., Huber, Bruce, McKee, Darren and Visbeck, Martin (2010) A seasonal cycle in the export of bottom water from the Weddell Sea. Nature Geoscience, 3 (8). pp. 551-556. DOI 10.1038/ngeo916.

[thumbnail of Visbeck.pdf]
Visbeck.pdf - Accepted Version

Download (865kB)
[thumbnail of ngeo916.pdf] Text
ngeo916.pdf - Published Version
Restricted to Registered users only

Download (6MB) | Contact

Supplementary data:


Dense water formed over the Antarctic continental shelf rapidly descends into the deep ocean where it spreads throughout the global ocean as Antarctic Bottom Water1, 2. The coldest and most voluminous component of this water mass is Weddell Sea bottom water1, 3, 4, 5, 6, 7. Here we present observations over eight years of the temperature and salinity stratification in the lowermost ocean southeast of the South Orkney Islands, marking the export of Weddell Sea bottom water. We observe a pronounced seasonal cycle in bottom temperatures, with a cold pulse in May/June and a warm one in October/November, but the timing of these phases varies each year. We detect the coldest bottom water in 1999 and 2002, whereas there was no cold phase in 2000. On the basis of current velocities and water mass characteristics, we infer that the pulses originate from the southwest Weddell Sea. We propose that the seasonal fluctuations of Weddell Sea bottom-water properties are governed by the seasonal cycle of the winds over the western margin of the Weddell Sea. Interannual fluctuations are linked to the variability of the wind-driven Weddell Sea gyre and hence to large-scale climate phenomena such as the Southern Annular Mode and El Niño/Southern Oscillation.

Document Type: Article
Keywords: Weddell Sea; physical oceanography; climate phenomena; Southern Annular Mode; El Nino; Southern Oscilliation
Research affiliation: OceanRep > GEOMAR > FB1 Ocean Circulation and Climate Dynamics > FB1-PO Physical Oceanography
Refereed: Yes
Open Access Journal?: No
Publisher: Nature Publishing Group
Projects: Future Ocean
Date Deposited: 05 Aug 2010 10:03
Last Modified: 23 Sep 2019 19:41
URI: https://oceanrep.geomar.de/id/eprint/8753

Actions (login required)

View Item View Item