Expressions of Intent for IPY 2007-2008 Activities

Expression of Interest Details

PROPOSAL INFORMATION

Seasonality as a cause of abrupt climate change: The East Greenland test  (Seasonality as a cause of abrupt climate change: The East Greenland test)

Outline
Recent work suggests that abrupt climate events are linked to seasonality (Denton et al., 2004). Evidence comes from the fact that Greenland ice cores show vastly different climate from that recorded by nearby glaciers. During the Younger Dryas, air temperatures over central Greenland were ~15C colder than at present(Cuffey and Clow, 1997; Severinghaus et al., 1998). In contrast, snowline lowering, reconstructed from assumed Younger Dryas age moraines, suggests summer temperature depression of <5.2C (Denton et al., 2004). The offset may be due to severe winters during the Younger Dryas causing the mean annual temperatures recorded by ice cores to be weighted towards colder values. This hypothesis, should it prove correct, has far-reaching implications for the cause of abrupt climate change. To test this hypothesis, we address several questions: What is the magnitude/timing of ice fluctuations? What were climate conditions that accompanied ice recession? Which are the Younger Dryas moraines? How does isostatic rebound affect snowline/temperature reconstructions? To answer these questions, we will map and date late-glacial and Holocene moraines in East Greenland. This area is particularly suitable, because it is adjacent to the Renland ice core that shows the same magnitude changes recorded at Summit. Moreover, moraines in this area intersect former sea levels and hence can be dated from relative sea-level information. Raised beaches and deltas in the area commonly contain datable shells. Moreover, these same shells also afford climate information, as species varied with ocean temperature. Complementary work may involve cosmogenic dating of moraines, which will allow us to compare two chronologic methods. A related component will be to model isostatic rebound - key for reconstructing former glacier snowlines (and hence temperature depression). Moreover, this work has important geophysical implications. Observations elsewhere of modern vertical displacement rates demonstrate steep local gradients in time and space of the earth's visco-elastic response that are difficult to see in global-scale models. In East Greenland, with its dramatic ice reduction and its proximity to the Icelandic hot spot, local response to glacial unloading can provide unprecedented information on the rheological structure of the lithosphere and shallow asthenosphere. We propose coupling global visco-elastic models with local three-dimensional finite element earth models to illuminate the uplift history. These data will be integrated with the glacial mapping and relative sea-level data to develop a complete synthesis of late-glacial and Holocene glacier, climate, and isostatic responses that will be used to address problems of abrupt change.

What significant advance(s) in relation to the IPY themes and targets can be anticipated from this project?
We will make significant advances towards reconstructing and understanding the mechanisms behind past changes in climate and ice sheets in Greenland (Theme 2). Our data will be applied towards understanding the present environment and towards predicting future abrupt global climate changes (Theme 3). An understanding of the role of seasonality in abrupt climate change is absolutely key for unravelling what drives global climate from both long (ice-age) to short (subdecadal) timescales. Geophysical/uplift data from this study also will have far-reaching global implications.Our work has a substantial natural science research (Target 1) and education/outreach component(Target 2 – see section 7 below).

What international collaboration is involved in this project?
At present, this project involves individuals from five institutions in four countries (United States, Denmark, Italy, Norway), all with a well-established history of polar research.

FIELD ACTIVITY DETAILS

Geographical location(s) for the proposed field activities:
This work will take place in east Greenland, centered on Scoresby Sund and adjacent fjords.

Approximate timeframe(s) for proposed field activities:
Arctic: 08/06 – 09/06      08/07 – 09/07      08/08 – 09/08
Antarctic: n/a

Significant facilities will be required for this project:
We will operate out of field camps supported by helicopter. We will require helicopters for camp moves and for close support. Helicopters, as well as chartered Twin Otter flights, are available at Constable Pynt at the mouth of Scoresby Sund.

Will the project leave a legacy of infrastructure?
We will produce a database of East Greenland radiocarbon dates that will be maintained on our website.

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

The logistics can be supported by NSF (through VECO) in conjunction with the Danish Polar Center at Constable Pynt. Travel to Constable Pynt is available on regularly scheduled flights from Iceland.

Has the project been "endorsed" at a national or international level?
Our expression of interest is in the process of being considered by 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?
Yes
We have carried out a short reconnaissance trip to East Greenland, but otherwise this is an entirely new project.

How will the project be organised and managed?
This project is sufficiently small that management is not overwhelming. Primary PIs, representing all involved nations, will create an informal steering committee directed by Dr. George Denton. The principal people involved will hold yearly meetings to ensure coordination among group members and integration and publication of results.

What are the initial plans of the project for addressing the education, outreach and communication issues outlined in the Framework document?
We will involve a native Greenlander in field work - either a university student, a native teacher or museum curator. We will develop a public, multilingual website. Other plans beyond the normal education of students and public lectures, include developing a museum exhibit and producing an educational video.

What are the initial plans of the project to address data management issues (as outlined in the Framework document)?
Data will be submitted to the World Data Center for Paleoclimatology. In addition, we will develop a database of East Greenland radiocarbon dates. All data will be made available on the project website.

How is it proposed to fund the project?
Resources (both financial and logistical) to carry out the work will be solicited from national funding agencies in the United States, Denmark, and Italy.

Is there additional information you wish to provide?
None

PROPOSER DETAILS

Dr. Brenda Hall
Climate Change Institute
303 Bryand
Orono, Maine
04469
USA

Tel: 207-581-2191
Mobile:
Fax: 207-581-1203
Email:

Other project members and their affiliation

Other Information