Expressions of Intent for IPY 2007-2008 Activities

Expression of Interest Details

PROPOSAL INFORMATION

Capturing Large-Scale Change in the Arctic Ocean and Cryosphere from Aircraft  (DeltaAOC)

Outline
Dramatic changes in the Arctic Ocean and its sea ice cover have been documented over the past few decades that are attributable to atmospheric forcing and longer-term climate change. The primary obstacle to complete understanding of the nature and genesis of the change is the difficulty of adequate sampling due to logistical problems associated with the year-round ice cover. With the dramatic scaleback of the SCICEX program since 2000, the oceanographic and cryosphere communities lost a platform to conduct long, basin-wide transects for initial and repeat measurements during all seasons. These measurements are critical for assessing the changing circulation patterns and to constrain models of ocean circulation and heat flow. Although the Arctic is being monitored with a judiciously undertaken program using other methods, synoptic measurements on a basin-wide scale are still lacking. Whereas synoptic sea-ice extent can be measured from satellite, synoptic sea-ice thickness is one of the critical factors missing in the present monitoring network. Synoptic ice thickness and upper ocean properties are critical for understanding the underlying causes for ocean-ice response to forcings. We propose to use a long-range US Navy P-3 aircraft in a collaboration between researchers from the US and Europe with three facets: 1) conduct synoptic, basin-scale, and repeat measurements of ocean temperature and salinity by dropping expendable CTD profilers into leads in the sea ice over critical regions of changing circulation in the Eurasian and Canadian Basins, 2) use radar and laser altimetry to measure Arctic ice freeboard from aircraft, and 3) fill in critical gaps in the gravity coverage over the Arctic Ocean. This work would be conducted over three field seasons, 2007-09, to establish a baseline of regional ocean circulation and ice thickness, and then to repeat the measurements to fully capture the change. By adding a laser altimeter to the standard radar altimeter, we can also measure sea-ice freeboard with the aim of inferring ice thickness. Accurate measurement of sea-ice freeboard from aircraft can 1) help perfect the technique of inferring ice thickness, and 2) provide calibration/validation for the CryoSat satellite that will be operational at the time. An important requirement for ice freeboard determination is an accurate geoid that can be used to “flatten” out the ice surface so that the altimeter returns off the water in the leads can be discriminated from the ice returns. Although good gravity measurements (required to produce the gravimetric geoid) exist over much of the ocean, there are still some important gaps in coverage. There is a region within the polar hole of the ERS altimetric gravity field in the Makarov Basin where the geoid is compromised by inadequate gravity coverage. With the NRL P-3 already in the Arctic for oceanographic and cryospheric assessment, it would be a perfect opportunity for gravity measurement in these areas.

What significant advance(s) in relation to the IPY themes and targets can be anticipated from this project?
With a P-3, we can make synoptic measurements of ocean properties and sea-ice freeboard instead of being limited to transects as are ships and submarines. Most importantly, we will provide an opportunity to establish a baseline assessment of sea-ice thickness and ocean properties over a region and then to later re-measure them to capture the temporal change.

What international collaboration is involved in this project?
We will be collaborating directly with Rene Forsberg, Danish Space Center, on this proposal. This proposal will provide a “basin-scale” complement to other smaller-scale European IPY programs to provide laser and radar altimetry for sea-ice measurement.

FIELD ACTIVITY DETAILS

Geographical location(s) for the proposed field activities:
We plan to work in both the Arctic Eurasian and Canadian Basins. Our flights will target important regions such as the Transarctic Ice Drift, the Beaufort Gyre, and the region north of Greenland and the Canadian Archipelago that is poorly measured due to heavy sea ice cover. The exact location of the surveys will be decided based upon the new results expected from the the SEARCH programs that are presently underway. In the Eurasian Basin, we will coordinate our surveys so as to overlap the European IPY programs and sea-ice camps.

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

Significant facilities will be required for this project:
We would operate from Longyearbyen, Svalbard for the Eurasian Basin work and either Thule, Greenland or Barrow, AK depending upon the finalized location of the Canadian Basin field work. No special support or other facilities would be required.

Will the project leave a legacy of infrastructure?
Yes. The data sets and baselines measured by this project will be important for years to come as constraints of models and for satellite calibration/validation. Any improvements made to the Arctic gravimetric geoid will benefit all satellite sea-ice thickness determinations in the future.

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

Has the project been "endorsed" at a national or international level?
Yes. Our primary objectives are in line with the recent NSF-sponsored Long-Range Aircraft workshop for the Antarctic and with the objectives in the NSF SEARCH initiative for assessing Arctic change.

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?
New

How will the project be organised and managed?
The overall scientific coordination will be the responsibility of the PI for NRL. NRL will organize and execute the field work with the input from collaborators as to survey design. NRL would also take the lead on the data processing for the Rene Forsberg would assist NRL with the evaluation of the altimeter data and the determination of ice freeboard. If sufficient gravity are collected, the Arctic Gravity Project compiled may need to be revisited.

What are the initial plans of the project for addressing the education, outreach and communication issues outlined in the Framework document?
This project would provide an educational opportunity for one or possibly two post-doctoral fellows at NRL and/or NOAA involved with the project. The results of our work will be disseminated to the scientific community and to the general public via websites maintained by NRL and NOAA as well as journal publications.

What are the initial plans of the project to address data management issues (as outlined in the Framework document)?
All data will be made available to NSIDC and NDGC within 12 months of measurement, and data will be available to the general public via websites by no later than 12 months after measurement.

How is it proposed to fund the project?
Funding will be requested through the US National Science Foundation, with possible aircraft support from ONR funds. Forsberg’s salary would be paid by the Danish Space Center

Is there additional information you wish to provide?
None

PROPOSER DETAILS

Dr Vicki Childers
Code 7421, 4555 Overlook Ave. SW
Washington, DC
20375-5350
USA

Tel: +1 202-404-1106
Mobile:
Fax: +1 202-767-0167
Email:

Other project members and their affiliation

Other Information