Full Proposals for IPY 2007-2008 Activities

Proposed IPY Activity Details

1.0 PROPOSER INFORMATION

(Activity ID No: 23)

1.1 Title of Activity
Bipolar Atlantic Thermohaline Circulation

1.2 Short Form Title of Proposed Activity
BIAC

1.3 Activity Leader Details
Tor Gammelsrød
University of Bergen
Norway

1.4 Lead International Organisation(s) (if applicable)
Scientific Comm. on Antarctic Research. (SCAR)
Climate Variability and Predictability (CLIVAR)
Climate and Cryosphere (CLiC)
World Climate Research Program (WCRP)

1.5 Other Countries involved in the activity
USA
United Kingdom
Chile
Russia
Italy
South Africa
Netherlands
Australia
Germany
France
Sweden
NULL
NULL
NULL
NULL
NULL

1.6 Expression of Intent ID #'s brought together in this proposed activity
51, 63, 320, 350, 280, 101, 300, 164, 731, 948, FP#136, FP#351

1.7 Location of Field Activities
Bipolar

1.8 Which IPY themes are addressed
1. Current state of the environment
2. Change in the polar regions
3. Polar-global linkages/tele-connections
4. Exploring new frontiers

1.9 What is the main IPY target addressed by this activity
1. Natural or social science

top of page

2.0 SUMMARY OF THE ACTIVITY

General: The aim of the proposed project is to study mechanisms, manifestations and impacts of bottom water formation on the bipolar Atlantic Ocean shelves. The proposed activity is to i) Identify key regions where dense water is formed and contributes to bottom water formation and thermohaline circulation; ii) Study cooling and freezing processes in these areas by remote sensing, in situ measurements and modeling; iii) Estimate production rates of dense water; iv) Study cascading of dense water towards the deep ocean by direct measurements and modeling of the bottom plume characteristics like velocity and turbulent structures; v) Measure and calculate the mixing processes in these downward cascading waters and obtain production rates of bottom water; vi) Define physical and biogeochemical controls on ocean carbon biogeochemistry; vii) Investigate relationships between variability in deep-water formation, CO2 uptake rates and large scale natural or anthropogenic climate forcing. viii) Study the relationships between variability in the bipolar deep-water formation and the global ocean circulation using the ROMS model system; ix) Study the role of the variability of Antarctic ice sheet for triggering glacial cycles by combining paleo-climatological sampling and paleo modeling.
Some specifications. Key areas are the Barents Sea, and southern Weddell Sea, but also other shelf seas will be studied. Parts of the study areas are frequently hard to access, so icebreakers are necessary. There are initiatives from USA (EoI 63) to support such activities and the Russians (731) plan to devote R/V “Academic Fedorov” for IPY activities. The actual vehicles must have installed state of the art equipment for hydro-chemical-biological-geological sampling (51). The dynamics of the dense water plumes will be investigated using bottom-tracking floats (51). Mixing processes on the shelves and in bottom-trapped cold-water jets will be studied using turbulence profilers (101). A separate experiment will be set up to study the unique nature of internal tidal mixing (948) particularly near the critical latitude (300). An important component of the consortium will be to study variability of ecosystems related to changes in extent and duration of sea ice cover (280).
To study areas not accessible by ships during the IPY years the use of long-range aircrafts dropping commercial expandable CTD’s and current profilers are planned (350). Using Aircrafts makes it feasible to sample the Makorov Basin, an area particularly sensitive to climate changes, and the ocean NW of the Canadian Archipelago that so far is under-sampled. In the Antarctic the Drake Passage and Western Weddell Sea should be sampled en route to the Southern Weddell Sea bottom water formation areas.
All activities mentioned above will include ocean modeling where ROMS is expected to be the main tool (320). The model results will be used as a tool to design the field experiments, helping to identify key areas and important processes. We also expect that our effort will be important input to global climate models in the future.
Paleo-climatological studies will include seismic lines, sediment coring and modeling.
Instrumentation to monitor the long-term variability of oxygen and carbon will be deployed in the plume regions. Integrated physico-biogeochemical studies will characterize the hydrographic and carbon biogeochemistry of the source waters prior to dense water formation. Studies of plume and deep-water properties will be examined to determine the anthropogenic carbon fluxes due to ventilation processes related to thermohaline circulation. Biogeochemical properties of the end members will facilitate a more concrete determination of the plume source water.

2.1 What is the evidence of inter-disciplinarity in this activity?
There will be activities in physical and chemical oceanography, geology, paleo-climatology, marine biology and glaciology. The main focus is physical oceanography and the controls on the thermohaline circulation. Another strong element of the activities is the integration of physics and biogeochemistry to elucidate the role of the circulation in ocean carbon transport and biogeochemical modifications.

2.2 What will be the significant advances/developments from this activity? What will be the major deliverables? What are the outputs for your peers?
By concentrating on the sources of deep- and bottom formation we will learn more about the driving forces of the global thermohaline circulation The role of the polar oceans including sea-ice and floating ice sheets on the global climate is not well understood. This cluster will provide further insight into key processes determining the formation rates of bottom water. The question on variability in CO2 uptake in Polar oceans is also addressed. These activities will give us a better understanding of climate variability in the past, a pre-requisite to understand global climate development in the future.

2.3 Outline the geographical location(s) for the proposed field work (approximate coordinates will be helpful if possible)

2.4 Define the approximate timeframe(s) for proposed field activities?

2.5 What major logistic support/facilities will be required for this project?
Icebreaker
Fixed wing geophysical aircraft
Ice strengthened research ship
Ship-based drilling capability
Ship recovery of buoys etc

2.6 How will the required logistics be supplied? Have operators been approached?

2.7 If working in the Arctic regions, has there been contact with local indigenous groups or relevant authorities regarding access?

top of page

3.0 STRUCTURE OF THE ACTIVITY

3.1 Origin of the activity
This is a new activity developed for the IPY period

3.2 How will the activity be organised and managed? Describe the proposed management structure and means for coordinating across the cluster
For the Antarctic activities we are planning a close co-ordination with EoI’s SASSI (9), Synoptic Antarctic Shelf-Slope Interaction Study) and CASO – Oceans (108), (Climate of Antarctica and the Southern Ocean – Ocean Circulation Cluster) . Both these proposals have a circumpolar observation plan with the same type of logistics and instrumentation needs as BIAC. A concerted effort in the Weddell Sea should be favourable for all parties. Also there seems to be a great potential for co-operation on the modelling side, since ROMS seems to be the main tool.
For the Arctic investigations we want to develop our plans together with CARE(133), (Climate in the Arctic and its role for Europe) and iAOOS (80) (Integrated Arctic Ocean Observing System). Both these EoI’s are very broad and general in their approach, and BIAC identify key elements of common interest. See the above mentioned clusters for further details.

3.3 Will the activity leave a legacy of infrastructure and if so in what form?
During the BIAC activities we will define key locations for future monitoring of environmental parameters to maintain long time series of relevance to global climate. Most of these will probably be in bottom-anchored moorings equipped with state of the art sensors.

3.4 Will the activity involve nations other than traditional polar nations? How will this be addressed?
Most of the participating nations are already involved in polar research. However, the training activity (ISIS 164) will be open for participants from non-traditional polar nations

3.5 Will this activity be linked with other IPY core activities? If yes please specify
SASSI(9), CASO Oceans (108), CARE (133), iAOOS (80)

3.6 How will the activity manage its data? Is there a viable plan and which data management organisations/structures will be involved?
BIAC will follow and contribute to the design of the IPY data management and policy plan. We will take advantage of existing data management structures and international data centres. Some nations plan to establish national committees for IPY data management.

3.7 Data Policy Agreement
Will this activity sign up to the IPY draft Data Policy (see website)
Yes

3.8 How will the activity contribute to developing the next generation of polar scientists, logisticians, etc.?
We plan to sample the most inaccessible parts of the polar oceans. This will provide important experiences for logistics in ice-covered areas in the future. Large and unique data sets becoming available will provide basis for a number of MSc and Phd theses, and will inspire scientists in many years to come. A summer school in ice physics (EOI 164) is also planned

3.9 How will this activity address education, outreach and communication issues outlined in the Framework document?
The data will provide basis for several MSc and Phd thesis. Utilising the infrastructure at Svalbard a summer school addressing polar issues in an appropriate environment. (ISIS 164) All results will be published in high-quality peer-reviewed journals and will also be made available in national languages to ensure outreach towards the public. Special efforts will be made to reach schoolchildren, media and politicians / decision makers. Web pages will be developed within the project for the purpose of public outreach both nationally and internationally, and data management Newspaper and television teams will be invited to join cruises and take part in the development of the project.

3.10 What are the proposed sources of funding for this activity?
Funding for individual projects will be sought by lead investigators from national agencies.

3.11 Additional Comments

top of page

4.0 CONSORTIUM INFORMATION

4.1 Contact Details

Lead Contact
Prof Tor Gammelsrød
University of Bergen
Geofysisk Institutt, Allegt 70
5007 Berge
Norway

Tel:          4755582695
Mobile:   +47 95210061
Fax:         +47 55589883
Email:       torg@gfi.uib.no

Second Contact
Dr Svein Østerhus
Bjerknes Centre for Climate Research
Geofysisk Institutt, Allegt 70
5007 Berge
Norway

Tel:          4755582607
Mobile:   +47 95189590
Fax:         +47 55589883
Email:      svein@gfi.uib.no

4.2 Other significant consortium members and their affiliation