Expressions of Intent for International Polar Year 2007-2008 Activities

Expression of Interest Details

PROPOSAL INFORMATION

Tidal Influences on Polar Processes (TIPP): Fieldwork, Theory, and Modeling  (TIPP)

Outline
Tides are a ubiquitous feature of the polar environment, impacting globally relevant processes such as: mixing of dense water overflowing the shelf edge; mean sea-ice concentration and roughness and associated ocean/atmosphere buoyancy and momentum fluxes; basal melt of ice shelves; tidally modulated flow of Antarctic ice streams and shelves; and solid earth deformation. Much progress has recently been made in the quality of ocean tidal models, but high-latitude tide prediction quality still lags well behind that for lower latitudes. This is attributable to poorly known bathymetry (especially under the large ice shelves), high latitude seas lying outside the footprint of the TOPEX/Poseidon satellite altimeter (the world’s most successful “tide gauge”), and inadequate physical understanding of coupling between ocean tides and sea-ice, ice shelves, and grounded ice. TIPP proposes a coordinated, multidisciplinary approach to tides to reduce errors in ocean and earth tidal models to the level needed for optimum exploitation of remote sensing data including the GRACE gravity mission, RADARSAT SAR, and ERS, ICESat/GLAS and Cryosat altimetry missions, as well as bedrock GPS data for post-glacial rebound studies. Achieving this goal requires advances in mapping of high latitude bathymetry and sub-ice-shelf topography, coupling sea-ice and ice shelves to ocean variability, and improved models of tidal dissipation. Thus, TIPP also synthesizes advances in measurement technology (including satellites and 3-D motion from ice shelf GPS), theory of ocean-forced sea-ice and ice shelf behavior at high frequencies and small spatial scales, and numerical modeling of the 3-D ocean and ice. TIPP goals are ambitious but are accessible in a reasonable time frame, relying on the coordinated use of modern tools (satellites and computational resources) and recent theoretical and numerical studies in ice/ocean interactions rather than on unfounded technology. Beyond the scientific merits, TIPP has 3 further virtues. 1. It relies on, and therefore drives, synergy between researchers from a variety of disciplines – e.g., solid-earth physicists working with oceanographers to improve the model of deformation under tidal loading – and skills (measurements, theory, and modeling). 2. The range of activities allows countries or research groups to choose a level of participation appropriate to them. For example, while large computational resources are required for polar (and then global) 3-D ocean/ice modeling, much can be learned through process studies run with existing community models on desktop PCs. 3. The program leaves a legacy of high latitude data and physical understanding (see Section 2.4, below) for long-term polar and global climate studies.

What significant advance(s) in relation to the IPY themes and targets can be anticipated from this project?
This project will lead to the explicit integration of tidal processes into models of high latitude oceans, ice, and solid earth deformation, and provide tools for extracting tides from remote sensing and in situ data sets whose primary uses are to expose seasonal and longer-term trends in the cryosphere (e.g., ice thinning, and fresh water redistribution, and post-glacial rebound). A successful outcome will contribute to improved predictions of the cryosphere’s natural time scales, and its response to climate variability. These results feed directly into the representation of polar regions in global coupled models that attempt to forecast climate change.

What international collaboration is involved in this project?
Presently, most work relevant to high-latitude tidal studies is carried out by the US, UK, and Germany, but with significant contributions also from other countries such as Canada, Denmark, Italy, Japan, Norway, Spain, and South Korea. We anticipate a role for more countries to participate (see section 3.6).

FIELD ACTIVITY DETAILS

Geographical location(s) for the proposed field activities:
Central Arctic, around the Antarctic margins, and on major Antarctic ice shelves (Ross, Filchner-Ronne, Amery). In most cases, fieldwork can be coordinated with other programs; e.g., bottom pressure recorders added to other ocean moorings, and GPS installation riding on ice shelf and other geophysical field programs.

Approximate timeframe(s) for proposed field activities:
Arctic: Throughout and beyond IPY            
Antarctic: Throughout and beyond IPY            

Significant facilities will be required for this project:
Icebreaker vessels for deployment and retrieval of bottom pressure recorders in the Arctic and Antarctic; fixed-wing or helo access to ice shelf GPS sites. Ship-based activities can be coordinated with other measurement programs (e.g., SASSI); ice shelf GPS can be coordinated with programs such as the US-led Amundsen Sea Embayment Program (ASEP) and UK fieldwork on the Filchner-Ronne and Larsen ice shelves.

Will the project leave a legacy of infrastructure?
Improved models of high-latitude ocean and earth tides (including ocean load tide) will be available as community resources for all users. Newly acquired measurements will be added to existing international data bases. We will construct a web-served data manager for high latitude tide-related data, encompassing ocean, sea-ice, ice shelf, and solid earth deformation records.

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

Most current tide-relevant work in the Arctic and Antarctic is now carried out by researchers funded by national agencies such as NSF, NASA and NERC. The requirements for TIPP can be met by a continuation of this process.

Has the project been "endorsed" at a national or international level?
Submitted to the US 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

Many activities are already partially funded or in proposal stage to national agencies, including NSF and NASA (USA), NERC (UK), the Danish National Space Center, and the Australian Antarctic Division. New activities involve field work for developing a high-quality in situ tide data set, plus a strong element of interdisciplinary interactions, initiated through a “Polar Tides” workshop (see 3.2., below).

How will the project be organised and managed?
The initial organization would involve convening a workshop, drawing on all fields of interest: glaciology, oceanography, sea-ice, and solid-earth geophysics. One goal of this workshop would be to select a Steering Committee, which would balance not only the various disciplines, but also researcher’s skills, i.e., modeling, theory and fieldwork, and both Arctic and Antarctic interests. Committee leadership would be chosen by the Committee. Regular workshops would be used to maintain the interactions between disciplines and across international boundaries.

What are the initial plans of the project for addressing the education, outreach and communication issues outlined in the Framework document?
Funding agencies such as the US NSF already require EOC activities as part of funded research. We anticipate that national agencies will fund undergraduate and graduate students at levels consistent with present practice. The public’s familiarity with the basics of tides and their enthusiasm for polar science makes the topic easy to explain through public lectures and the web.

What are the initial plans of the project to address data management issues (as outlined in the Framework document?
Most tide-related data (e.g., tide height records, satellite altimetry, current meter data) are already archived in national and international repositories. The proposed project would ensure that all appropriate data are archived, and also create a web server that links all known tide-related data time series and applies consistent tidal analyses to these data.

How is it proposed to fund the project?
We anticipate that the primary source of funding will be through the national funding agencies. Many tide-relevant programs are already active or under review. In many cases, the acquisition of tide-relevant data can be achieved in collaboration with other IPY and core field programs, minimizing logistics costs and so providing opportunities for smaller groups to participate.

Is there additional information you wish to provide?
The physics of oceanic and solid-earth tides are quite well understood, however the coupling between these tides and cryospheric response is not. Part of the problem stems from a lack of coordination between researchers in different areas. We hope to overcome this. Participation of non-traditional high-latitude countries will be strongly encouraged: low-cost opportunities in both field work and modeling include: (1) numerical modelling of specific regions and processes; (2) participation in field programs; (3) purchase of resources for obtaining tidal measurements (e.g., bottom pressure gauges and GPS receivers) for deployment by the countries with existing high-latitude logistics in place.

PROPOSER DETAILS

Dr Laurence Padman
3350 SW Cascade Ave
Corvallis, OR
97333-1536
USA

Tel: (1) 541-753-6695
Mobile: (1) 541-760-1421
Fax: (1) 541-753-1999
Email:

Other project members and their affiliation