The dynamic response of Arctic glaciers to global warming
Project DescriptionShort Title: GLACIODYN
Project URL: http://www.glaciodyn.org
Proposal URL: http://classic.ipy.org/development/eoi/proposal-details.php?id=37
Global warming will have a large impact on glaciers in the Arctic region. Changes in the extent of glaciers will effect sea level, and may lead to substantial changes in sediment and fresh water supplies to embayments and fjords.
In ACIA, a simple approach was taken to estimate the runoff of all glaciers in the Arctic for a set of climate-change scenarios. Changes in the surface mass balance were calculated without dealing with the fact that glacier geometries will change. It was also assumed that the rate of iceberg production at calving fronts would not change.
To arrive at more accurate predictions, we propose an internationally-coordinated effort to study the dynamics of Arctic glaciers and develop new tools to deal with this dynamic response. The key elements of this effort are
(i) to make better use of observational techniques to assess the detailed dynamics of a key set of glaciers, and
(ii) to develop models that can be used to aggregrate data and that are sufficiently robust to have predictive power.
A set of target glaciers have been identified for intensive observations (in situ and from space) for the period 2007-2010. This set covers a wide range of climatic/geographical settings and takes maximum advantage of prior long-term studies.
The target glaciers are:
- Academy of Sciences Ice Cap (Severnaya Zemlya)
- Glacier No. 1 (Hall Island, Franz Josef Land)
- Austfonna (Svalbard)
- Hansbreen (Svalbard)
- Kronebreen (Svalbard)
- Kongsvegen (Svalbard)
- North Scandinavia transect (Langfjordjøkelen, Storglaciären, Marmaglaciären)
- Vatnajökull (Iceland)
- Kangerlussuaq basin (West Greenland)
- Devon Ice Cap (Canada)
- McCall Glacier (Alaska)
- Hubbard Glacier (Alaska)
- Columbia Glacier (Alaska)
Among the target glaciers are glaciers for which information is available on length/area in historical times [reports, drawings, photographs, old maps, etc.]. This information will be combined with the newly derived maps to reconstruct glacier evolution from the Little Ice Age into the present. This will provide a better perspective for projecting changes in the coming century.
Special attention will be given to tidewater glaciers. We want to look carefully at the interaction between surface processes and dynamics (e.g. the influence of meltwater supply on ice velocities and consequently calving rates; interactions between terminal moraines, sediment flux, and ice velocities). In a warming world some glaciers will transform from cold to polythermal, or from polythermal to temperate. We want to study the effect of such transitions on glacier dynamics and related rates of retreat. Another important aspect of study is the surface albedo. Poor drainage of meltwater may lead to more extensive zones of soaked snow and supraglacial lakes (as seen in large parts of the Greenland Ice Sheet), thus enlarging the sensitivity of ablation rates to warming.
Model development will be conducted in parallel with the observational programmes. The modelling work will deal with processes acting on the smaller scale (e.g. parameterization of the calving process) and on the larger scale (e.g. global dynamics of tidewater glaciers, response to climate change, interaction with sediment dynamics).