Expressions of Intent for International Polar Year 2007-2008 Activities

Expression of Interest Details

PROPOSAL INFORMATION

Southern Ocean Network to Assess Observations of Marine Currents and Hydrological Properties at the base of the Antarctic Continental Margin  (SON)

Outline
The Southern Ocean connects the three major ocean basins permitting the largest water mass exchange between the south Pacific, Indian and Atlantic Oceans through the Antarctic Circumpolar Current and a powerful control on global climate. The general surface circulation mainly conforms the flow pattern of the wind driven circulation, whilst the deep pattern results largely inferred from the internal density structure further modified by the bottom topography. The Antarctic Bottom Water forms all around the continental margin following complex air-sea-ice interactions and mixing processes between the warm and saline Circumpolar Deep Water provided from oceanic circulation and cold Antarctic waters formed on the shelves with varied characteristics. The shelf waters result rather denser than the bottom waters, thus they descend into the deep ocean turning to the west because of the earth’s rotation in geostrophic balance with the strong eastward flow of the Antarctic Circumpolar Current. Exceptions from this interior dynamics can arise from some bathymetric features, like canyons, isobath depressions, mound-shaped sedimentary bodies situated near the base of the continental slope. Current measurements in the deep layer call not only to estimate oceanic transports but also to quantify bottom current regimes, which are thought to have been responsible for sedimentary processes above the sea-floor bed. Joint analyses of deep currents, suspended and bed-load sediments may help to relate through record variations downward flux of biogenic materials and changes in ecosystem dynamics. SON intends to promote a coordinated action to provide long-term measurement (order of 5-10 years) of marine currents and water mass properties within the circum-Antarctic Continental margin. The scientific approach will pursue the following objectives:1) to estimate down-slope dynamics and associated meridional transports;2) to detect any changes in dense water mass properties that are converted into the denser Antarctic Bottom Water; 3) to provide experimental frameworks for evaluating ecosystem responses to climate variations, considering possible longitudinal gradients and downward fluxes of biogenic material; 4) to integrate geological and geophysical records (sediment depositions, seismic facies) with the hydrosphere dynamics;5) to leave a legacy providing sustainable and well-integrated observations of marine currents, water mass properties, sedimentary and biostratigraphic evidence of biogenic material.Appropriate processed-oriented modelling studies will be used to fully exploit these measurements and to provide a quantification of the buoyancy modification, dense water formation rates, bottom water flows in controlling sediment transports and depositional processes within the confine of the continental margin.

What significant advance(s) in relation to the IPY themes and targets can be anticipated from this project?
SON will provide advances in: synoptic observations capturing sub-ice dynamics, water mass modifications and ecosystem variations through space, as documented in the sediment depositions (Theme 1); changes in dynamics considering water mass instabilities and ice-sheet evolution from satellite technologies covering daily and longer time scale (Theme 2). A hierarchy of models will be targeted to quantify: 1) the implication of the topography on volume and fine sediment transports; 2) the effect of the canyons canalisation on depositional processes; 3) changes in the past dynamics from biostratigraphic evidences to serve ecosystem studies.

What international collaboration is involved in this project?
SON fits the initiatives within: SCOR/iAnZone programmes; CLIVAR/CliC/SCAR supported actions as “Southern Ocean CHOKEPOINTS” and “CASO: Climate in Antarctica and Southern Ocean”. Bilateral cooperation with IAA, Argentina, CRC and CSIRO, Australia. Furthermore, SON closely integrates DEEPSPOTS, which has proposed the deposition of a multidisciplinary seafloor observatory in the Weddell Sea.

FIELD ACTIVITY DETAILS

Geographical location(s) for the proposed field activities:
Candidate key sites for mooring locations are: offshore the Ross Ice Shelf, offshore the Wilkes-Adélie Land, along the Antarctic Peninsula to the west, to the east in the Weddell Sea and through narrow passages at the Weddell-Scotia Confluence where dense waters from the Weddell Sea escape into the Argentine Basin.

Approximate timeframe(s) for proposed field activities:
Arctic: n/a
Antarctic: 12/06 – 03/07      12/07 – 03/08      12/08 – 03/09

Significant facilities will be required for this project:
SON requires ice-strengthened research ships for mooring services, hydrographic surveys and profiling float releases. Ship time may include surveys and samplings for other IPY projects (e.g. CTD/XBT data, sediment coring, multibeam swaths, etc.). Moreover, deployment/recovering of moorings and profiling floats will rely upon ice-breaker operations in supplying the Antarctic bases.

Will the project leave a legacy of infrastructure?
Taking advantages of shared logistics, SON will establish a basis for continuous observations, providing long time-series (order of 5-10 years) pertaining to the hemipelagic regions. These initiatives should promote interdisciplinary researches, attracting future national funding and living to the next generation new integrated datasets pertinent to the Southern Polar Regions.

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

In view of the circumpolar coverage of the Southern Ocean, SON seeks for coordinated actions with planned field activities. This implies the participation of personnel on board of other ships.

Has the project been "endorsed" at a national or international level?
SON addresses major questions within EUR-OCEANS for system integration in physical, biochemical and ecosystem sciences. Spaced time series of currents, profiling floats and synoptic hydrological observations have been endorsed by CLIVAR/CliC/SCAR Southern Ocean Panel. The EoI is in the processes of being considered by the Italian National Committee for IPY.

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?
Expansion

The effective field program aimed at studying the effects of the down-slope dynamics on sediment depositions at the base of the circum-Antarctic continental margin is a new initiative. However, this proposal is meant to complement the major field phase activities within the SCOR affiliated iAnZone programme (SASSI) for the IPY.

How will the project be organised and managed?
SON shall represent coordinated efforts among national programmes establishing links with SCAR/SCOR group of experts. A first pilot experiment offshore Wilkes-Adelie land had received endorsement from Italian PNRA (WAVES). Accordingly, the calendar should be established as follows: March-April 2005, meeting for detailed proposal preparation;May-June 2005, final proposal and applications for national funds; July-October 2005, preparation mooring deployment (Austral summer 2005-2006); March-September 2006, meeting, first results, preparation mesoscale experiment (2006-2007); March-June 2007, SON kick-off meeting;The organization and management of the proposed project during the IPY (2007-2009) will be coordinated within SASSI Steering Committee, including planning meetings, annual meetings, etc.

What are the initial plans of the project for addressing the education, outreach and communication issues outlined in the Framework document?
SON requires work at sea and at home for testing modern observational technologies, data analyses and modelling works. SON intends to train masters in marine technologies, Ph-D in environmental fluid dynamics, ecosystem dynamics from geological and sedimentary histories in the SO. Communication tools will be based on web pages.

What are the initial plans of the project to address data management issues (as outlined in the Framework document?
Regular reporting of cruises and mooring inventories according to IOC/IODE methods and standards; archiving of data and metadata; free access to these information through well organised web pages communications; close relationships between data management structure and scientific teams for data access. The project portal will be integrated with JCADM site.

How is it proposed to fund the project?
Funds and ship times will be sought through national polar programmes. However, strong collaborations will be activated with IAA, CRC and CSIRO Marine Research, and other agencies involved in CLIVAR/CliC/SCAR iAnZone, GoodHope and CHOKEPOINTS umbrellas to share research infrastructures and logistics.

Is there additional information you wish to provide?
The mooring sites must be located in the regions identified as the major source of deep and bottom waters indicated above. In the majority of these sites detailed echo-sounder maps exist or refined multibeam swaths will be provided within the EoI/COMBINE. The programmes SCOTIA, MAGICO, WEGA/MOGAM, had concerned the South Scotia Ridge, the continental rise west of the Antarctic Peninsula, and the Wilkes-Adélie Land continental margin, respectively. Base studies on bottom dynamics, sediment depositions and biostratigraphic evidences in these sites have been preliminarily discussed with potential partners. Additional discussions are required for other sites.

PROPOSER DETAILS

Dr  Beniamino Bruno Manca
Istituto Nazionale di Oceanografia e di Geofisica Sperimentale -OGS
Borgo Grotta Gigante, 42/c,
SGONICO-Trieste
34010
Italy

Tel: +39.040.2140201(direct), +39.040.21401(answering machine)
Mobile: no
Fax: +39.040.2140266/+39.040.327307
Email:

Other project members and their affiliation