Expressions of Intent for International Polar Year 2007-2008 Activities

Expression of Interest Details

PROPOSAL INFORMATION

Transport through gaps across the Kerguelen Plateau and inter-basin exchange  (Cross-Kerguelen Exchange)

Outline
The main climatic role played by the Antarctic Circumpolar Current (ACC) lies in that it redistributes mass, water properties and dissolved gases between the southern Atlantic, Indian and Pacific Oceans. The ACC is strongly steered and restricted by topography, and the Kerguelen Plateau appears as one of a few major barriers for a continuous circumpolar deep-water pathway. Although two thirds of the ACC are believed to flow to the north of Kerguelen Islands, most of the remaining part, south of the Polar Front, pass through two deep gaps across the Kerguelen Plateau: the Fawn Trough in the midway (56-57°S) and the Princess Elizabeth Trough between the southern edge of the plateau and Antarctica. The streams that exit from these troughs form a northward flowing western boundary current along the eastern slope of the plateau before they leave it to join the main ACC core. Thus, they contribute substantially to inter-basin exchange of deep water between the Weddell-Enderby Basin to the west and Australian-Antarctic Basin to the east. In addition, on the southern end of the Elizabeth Trough is the westward flowing Antarctic coastal current entering into the Prydz Bay, a probable source region of Antarctic Bottom Water in the Indian sector of the Southern Ocean. However, our knowledge of the transport through these troughs and the associated inter-basin exchange of circumpolar water masses is very limited owed to insufficient measurements.We propose here to quantify these parameters by making a series of year-long current measurements from several moorings deployed across the two troughs, as well as cross- and along-trough CTD and biogeochemical measurements. The previous WOCE section I8 as well as the CTD and currentmeter mooring data from the KEOPS cruise (January-February 2005) on the northeastern part of the Kerguelen Plateau will form a valuable supplementary data set. We will also make use of our on-going upper-layer CTD measuring network using instrumented elephant seals (SEaOS), which has already been installed in this region since the early 2004. In addition to their oceanographic uses, the physical and biochemical parameters obtained, especially those from the Antarctic costal zone, will be usefully integrated in the ecological study of sea mammals winter-feeding in the region. They will also be used as in-situ validation means for animal-borne “ARGO” measurements that feed the CORIOLIS/GODAE Center at IFREMER working as part of the ongoing Operational Oceanography effort. In short, this experimental work has important implication both for climatology and biodiversity of the Antarctic Ocean.

What significant advance(s) in relation to the IPY themes and targets can be anticipated from this project?
Quantification of the water flux through two major topographic gaps across the Kerguelen Plateau (Fawn Trough and Princess Elizabeth Trough), which is poorly known because of the lack of direct current measurements of sufficient duration;- Quantification of deep-water properties exchanged between the Weddell-Enderby Basin and the Australian-Antarctic Basin;-Monitoring of the formation rate of Antarctic Bottom Water or deep water in the Prydz Bay area;-Validation of animal-borne autonomous measurements;-Strengthening of the interdisciplinary work between physics, biogeochemistry and Antarctic predators’ feeding ecology.

What international collaboration is involved in this project?
As the projects of many nations are still developing, we are searching for foreign partners having similar scientific interest and possibly sharing ship time especially for the Princess Elizabeth Trough region. Possible candidate countries having ice-strengthened research vessels and possessing nearby Antarctic stations are: Japan, Australia, Russia.

FIELD ACTIVITY DETAILS

Geographical location(s) for the proposed field activities:
Fawn Trough region (56-57°S, 75-80°E): 3 lines of subsurface current moorings (3 CM each for 1 year), along- and cross-trough CTD sections;-Princess Elizabeth Trough region (62-67°S, 80-85°E): 5 lines of subsurface current moorings (3 CM each for 1 year), along- and cross-trough CTD sections.

Approximate timeframe(s) for proposed field activities:
Arctic: n/a
Antarctic: 01/08 – 02/08 CM moorings + CTD      01/09 – 02/09 CM mooring recovery + CTD      

Significant facilities will be required for this project:
-Southern Ocean-going research or supply vessels (e.g., French Marion Dufresne II, Russian, Australian or Japanese ice-strengthened vessels)- A possibility of sharing ship time with a Russian project (Leitchenkov et al. “Prydz Bay-Kerguelen Plateau Geotransect”) will be examined

Will the project leave a legacy of infrastructure?
No

How is it envisaged that the required logistic support will be secured?
Consortium
Own national polar operator
Another national polar operator

If the present project is selected, a ship time request to the IPEV/IFREMER via French IPY National Committee will be deposited. At the same time, other possibilities to share ship time with other countries having a similar project (Russia) or nearby permanent Antarctic stations (Japan, Australia) will be envisioned.

Has the project been "endorsed" at a national or international level?
The present project is one of a few suggestions from the French Antarctic interdisciplinary community, especially between the ocean physics and sea mammal ecology in the Kerguelen region, which should be further discussed for international cooperations, in particular, for logistics.

PROJECT MANAGEMENT AND STRUCTURE

Is the project a short-term expansion (over the IPY 2007-2008 timeframe) of an existing plan, programme or initiative or is it a new autonomous proposal?
Yes

Although this is a new proposal, it benefits from several existing programmes in the same area, such as: “Temperature and salinity profile measurements in the Southern Ocean using southern elephant seals as oceanographic sampling platforms/ SEaOS” (since January 2004), see the IPY Expression of Intent “Novel Exploration of Oceans – Pole to Pole/NeOPP” by K. Kovacs; “A multidisciplinary oceanographic cruise KEOPS” (January-February 2005); “A time series station CLIOKER” (since 1999).

How will the project be organised and managed?
-By June 2005: Search for international cooperations; Submission of the final project to the International and National IPY Committees;-October 2005: Submission of the project to the potential funding agencies (IPEV, IFREMER, CNES, INSU/CNRS); -February 2006: Ask for use of Marion Dufresne (IPEV, IFREMER). If negative, find an alternative to share ship time on a foreign research/supply vessel (Russia, Japan, Australia);-2007: Preparation of the cruise (CM moorings, ADCP and CTD materials)- Jan-Feb 2008: Field work (CM moorings + CTD sections)-Jan-Feb 2009: Recovery of CM moorings + CTD sections

What are the initial plans of the project for addressing the education, outreach and communication issues outlined in the Framework document?
-Preparation of a web site of the project- Special seminars for large public in the National Museum of Natural History-Contact to mass-media for publicizing the field work and its implication

What are the initial plans of the project to address data management issues (as outlined in the Framework document?
Supply in near-real time raw data to numerical assimilation groups- Post-cruise calibration and validation of data- Submit the validated data in due time to one of the IPY designated data center

How is it proposed to fund the project?
After the evaluation of the scientific merit of the project by the International and National IPY Committees, the funding will be asked to national funding agencies (c.f. 3.2)

Is there additional information you wish to provide?
As most national projects are believed to have been prepared without knowing exactly about other countries’ intentions, it may be desirable that the International IPY Committee provides to each proponent with information of all projects on site by site basis. This is the most critical issue in seeking an international cooperation for logistics especially when the field experiments are planned to be taken place in ice covered area.

PROPOSER DETAILS

Young-Hyang Park
Muséum National d’Histoire Naturelle (MNHN)
Département des Milieux et Peuplements Aquatiques,
USM402/LODYC, 43 rue Cuvier
75231 Paris Cedex 05
France

Tel: (33) 1 40 79 31 70
Mobile: no
Fax: (33) 1 40 79 57 56
Email:

Other project members and their affiliation