Expressions of Intent for International Polar Year 2007-2008 Activities

Expression of Interest Details

PROPOSAL INFORMATION

CANADA #69: Water Content and Permafrost Monitoring in the Canadian Arctic using Gravimetry  

Outline
The Canadian geodesy community proposes to utilize gravity data from the GRACE satellite, combined with precise in situ measurements to monitor changes in the total storage of water snow and ice in the Canadian Arctic. In addition to measurements of total water storage this represents an opportunity to perform non-invasive monitoring of permafrost stability. The GRACE (Gravity Recovery and Climate Experiment) mission, successfully launched on March 17, 2002, is producing a new model of the Earth’s gravity field with unprecedented accuracy every 30 days for 8-10 years. The twin GRACE satellites are new remote sensors for ‘watching’ global climatic changes through measuring the temporal Earth’s gravity changes. The accuracy of the measurements are expected to enable us to infer ocean surface currents and ocean heat transport, sea-floor pressure changes, ocean mass changes, the mass balance of ice sheets and glaciers, and changes in the storage of water snow and ice on the continents. Simulation analysis shows that it will be able to recover water storage variation signals to about 1 cm or better for basins where the effective radius is 250-300 km or larger. The GRACE mission provides us with an opportunity to monitor the annual pattern of large-scale mass changes in Canada’s arctic for the duration of the GRACE mission. The data collected by GRACE is of unprecedented quality and could establish a baseline for long-term changes if we acquire the necessary complementary data sets such as laser altimetry data from ICESat (Ice, Cloud, and land Elevation satellite, NASA). Several missions, including SMOS (ESA, Soil Moisture and Ocean Salinity, 2007), HYDROS (NASA, the Hydrospheric States mission, 2009), and CloudSAT (NASA, 2005) will follow. The effects of climate change in the Arctic frequently involve the quantity of groundwater or ground-ice. In the arctic, permafrost changes and evolution of tundra and bogs are anticipated. Changing temperature and rainfall patterns will affect the quantity of ground water and ground ice, affecting drinking water supplies. The GRACE mission has potential to improve our knowledge of seasonal, annual and long-term water storage changes by providing monthly water and snow storage maps over the globe. Monitoring of the near coast glacial ice mass (volume) is possible, potentially making a significant contribution to climate monitoring. Groundwater is an important input to weather forecasting models, and is of importance in the south for the health of Agriculture and Forests. Warmer temperatures in the Canadian Arctic will affect the stability of permafrost. Ultimately the possible thawing and melting of ice-rich permafrost could present significant local and/or regional geohazards. Although traditional monitoring networks or observatories (i.e. primarily borehole and thermistor) may provide temporally regular measurements, they may not necessarily provide a complete (or fully representative) sampling of a permafrost structure. A direct measure of the change of mass in ice-rich permafrost can be monitored across a given structure by using the micro-gravity method repeated periodically across a network of stations. This method uses sensitive instrumentation to periodically measure the gravitational field (i.e a geophysical exploration tool) and is inherently a non-invasive technique. Precise micro-gravity measurements serve both purposes, ground-truthing of satellite data as well as local monitoring of mass changes related to permafrost degradation.

What significant advance(s) in relation to the IPY themes and targets can be anticipated from this project?
Current state of the polar environment - Improved knowledge of total mass of ice/water in the arctic - Improved understanding of climate change induced arctic hazards, including changes to permafrost and subsidence. Change in the polar regions - The ground-truthed satellite data provides a baseline for the lifetime of the GRACE mission, and we will make every effort to extend this beyond the lifetime of GRACE, enabling a long-term large-scale and revolutionary new method of monitoring climate change via gravity measurements from space. - A legacy geodetic infrastructure will be established to support Geoscience and economic activities. Polar-global linkages and interaction Better modelling and prediction of climate induced changes involving mass changes, uplift or subsidence.

What international collaboration is involved in this project?
This project adds to the recently completed Arctic Gravity Project, which involved over 10 different nations. The GRACE satellite is an international collaborative venture. Canada is not a partner in this effort, but NRCan staff have been contributing to data validation and have been invited to attend and give presentations to internal satellite project team workshops. This project fits well with Cryosphere projects, including the Greenland project of Alexander Braun (U. Calgary).

FIELD ACTIVITY DETAILS

Geographical location(s) for the proposed field activities:
This study would focus on the Canadian Polar Regions as defined in the Canadian Polar Commission Act (1991). There are two potential locations for field gravity data collection: Between 68 and 80 degrees West longitude Between 60 and 64 degrees North latitude OR Between 128 and 141 degrees West longitude Between 67 and 71 degrees North latitude

Approximate timeframe(s) for proposed field activities:
Arctic: 06/2007 – 09/2007      06/2008 – 09/2008      06/2009 – 09/2009
Antarctic: n/a

Significant facilities will be required for this project:
Exact sites for measurements have not been determined (see Section 2.1). There may be a need for transportation support for survey staff and the gravimeter to arctic sites (through PCSP or the Canadian Military?). The gravimeter requires a small tent and a generator. Each site occupation lasts about one full day (24 hours).

Will the project leave a legacy of infrastructure?
This project builds on existing projects and strengthens the Canadian Spatial Reference System (CSRS) in the region where it has the sparsest coverage and the greatest need for new infrastructure. A recent study conservatively estimates the socio-economic contribution from the CSRS to Canada’s annual GDP at more than $20B. This project provides a legacy in the Canadian Arctic of precisely positioned geodetic monuments, which have well determined gravity values. In particular we anticipate that this infrastructure would be in the McKenzie Valley/Delta, supporting ongoing geomatics efforts in this area. These monuments provide support for user positioning in the CSRS as well as gravity surveys for industrial, mineral exploration and scientific applications.

How is it envisaged that the required logistic support will be secured?
Military support
Own support
Other sources of support

Exact sites for measurements have not been determined (see Section 2.1). There may be a need for transportation support for survey staff and the gravimeter to arctic sites (through PCSP or the Canadian Military?). The gravimeter requires a small tent and a generator. Each site occupation lasts about one full day (24 hours).

Has the project been "endorsed" at a national or international level?
Yes. This pre-proposal has been reviewed and is being submitted by the Canadian Steering Committee (CSC). Ongoing discussions will integrate this pre-proposal into a larger network of related national and international initiatives. The CSC has initially sorted this pre-proposal into: Variability and Change in the Canadian Cryosphere. This project adds to the recently completed Arctic Gravity Project which involved over 10 different nations.

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?


NRCan’s participation (Geodetic Survey Division and Geological Survey of Canada) builds upon the work of the department’s Canadian Geodetic Service as well as the Climate Change and Geomatics for Northern Development Programs. A project entitled “Space Gravimetry Contributions to Earth Monitoring” has been approved within the GEOIDE NCE in Canada to investigate the usage of GRACE data, which would be complementary to this IPY effort. This project could be associated with the ArcticNet NCE in Canada. Further partnerships at NRCan would be developed, including links to experts in the Groundwater, Climate Change and Natural Hazards areas. Potential links to Environment Canada and the Department of Fisheries and Oceans will be pursued.

How will the project be organised and managed?
The project leader will organize meetings and workshops including ones at events such as the Canadian Geophysical Union meetings, where participants can meet at low cost with student participation. NRCan will manage the fieldwork internally. Additional deliverables and responsibilities are being discussed. NRCan activities will be organized within existing NRCan “programs” and will be managed within the existing program framework. Partner deliverables will be specified and reported upon as required for NRCan and the IPY secretariat. This project proposal is submitted with the participation of several universities and Natural Resources Canada (NRCan). The Geodesy Section of the Canadian Geophysical Union has strongly contributed to the development of this pre-proposal.

What are the initial plans of the project for addressing the education, outreach and communication issues outlined in the Framework document?
The project participants will investigate opportunities within other Canadian IPY projects to leverage outreach and education efforts. Other opportunities will be investigated. NRCan has an active Northern outreach and education program related to user positioning and geodesy that will likely be expanded during IPY.

What are the initial plans of the project to address data management issues (as outlined in the Framework document?
Data management would be performed by Natural Resources Canada’s Canadian Geodetic Service and made available for precise positioning applications in the arctic. Data is available free via the internet, usage levels are monitored, and an efficient client support group is available for support. Data would be submitted to the relevant services of the International Association of Geodesy for additional archiving and global usage.

How is it proposed to fund the project?
Funding has not been secured for this effort at this time. Approximate budget requirements are provided. Actual costs are highly variable depending on the number of sites surveyed and their location. Activities requiring funding from 2007 to 2009 include: 1. Absolute Gravity & GPS survey at 12 sites?: a) Transportation ($30K? each year), b) NRCan Salaries (including overtime) ($30K? each year), c) Instrumentation Maintenance ($5K each year) 2. GRACE & in situ gravity analysis (1PY @ NRCan) ($100K each year) 3. Graduate Student stipends (4 PhD, 19K each) ($80K each year) 4. Networking Activities (Travel/Conference Support) ($22K each year). Total project costs for 2007-2008 = $270K, 2008-2009 = $270K, and total ongoing costs of project = $200K.

Is there additional information you wish to provide?
The potential of the GRACE mission can only be realized through systematic validation and calibration using ground-based geodetic and hydrological data. The objective is to give a realistic evaluation of GRACE’s capability in monitoring climatic changes, especially in the surface water, snow and ice storage. Collecting hydrological data, converting to surface water equivalent, and then to equivalent gravity change will allow us to assess GRACE’s capability to capture the hydrological change signals. Prior to a formal proposal, we would investigate the special nature of the arctic environment including water storage issues. The nature of the project results would have to be such that trends longer than the lifetime of a single satellite mission are captured. Upon identifying suitable targets, studies may be calibrated against a portion of an existing permafrost network (e.g. Canadian Permafrost Network [GSC]). Thawing of permafrost and subsequent drainage of meltwater will result in a change of mass. Repeated gravity surveys at the same stations across a network can measure those changes in the mass of ice/water with an accuracy of better than 10cm of equivalent water. The micro-gravity method, however, is subject to even small changes in station height and thus requires precise-GPS height positioning. To attain the highest accuracy it is necessary to separate any vertical position change, either regional (e.g. post-glacial isostatic adjustment) or localized (e.g. subsidence), from measured changes in mass. For this activity the precise positioning requirement is not a limitation, but rather, a strength because direct measurements of the loss of permafrost mass will be linked to coeval measurements of subsidence. Additionally if a targeted area is suitable for the use of a remote sensing method (e.g. differential InSAR), the remote sensing technique could be used to map the larger spatial pattern of subsidence across a region - with the advantage of being linked to direct in situ measurements of permafrost depletion.

PROPOSER DETAILS

Chief, Gravity and Geodetic Networks Organisation Calvin Klatt
Geodetic Survey Division, Natural Resources Canada
498J, 615 Booth Street
Ottawa, Ontario
K1A 0E9
Canada

Tel: (613) 943-0019
Mobile: no
Fax: (613) 947-3602
Email:

Other project members and their affiliation