Expressions of Intent for IPY 2007-2008 Activities

Expression of Interest Details

PROPOSAL INFORMATION

Ice sheet / atmosphere exchange at Summit, Greenland  (ISUX)

Outline
Located in the center of the Greenland ice sheet, Summit provides an exceptional site for investigating thermal properties of snow, the atmospheric boundary layer (ABL), and ultimately surface energy fluxes in an Arctic environment. Our overall goal is an improved understanding of the exchange between the Earth’s surface and the atmosphere and ultimately to improve predictability of weather and climate. The presence of a snow cover substantially modifies the surface-atmosphere heat fluxes. Namely, the albedo of the surface, the absorption and penetration of shortwave radiation, and the thermal properties of snow play an important role in the surface energy budget and the stability of the atmosphere. Thermal and textural properties of snow influence the conductive heat flux and thus the skin temperature which is a key quantity driving the infrared and turbulent fluxes at the surface. Thus, a good understanding of the dominant processes involved in the snow cover evolution (precipitation, melt, blowing snow, and surface sublimation) is crucial. The proposed measurements include temperature and density profiles in the snow to infer snow thermal conductivity, and to determine the subsurface heat flux. In addition, atmospheric variables (wind speed, temperature, and humidity), radiative fluxes, and turbulent fluxes will be measured to calculate a complete surface energy budget, turbulent and mean atmospheric profiles. Special emphasis will be on surface-atmosphere coupling(conductive heat flux, turbulent heat fluxes and turbulent momentum fluxes) and on the diurnal variations of these fluxes. Measurements will be used to calculate, validate, and extend a sigma-coordinate multi-layer thermodynamic model. In addition, we will focus on improving the simulation of the turbulent exchange between the snow and the ABL using Large Eddy Simulation (LES). We propose to measure spatial and temporal turbulence data with arrays of sonic anemometers and other fast response instruments. These data sets, available for the broad scientific community, will be fundamental for the assessment of subgrid-scale models used in numerical codes by international research teams for providing further guidance in the construction of new-generation parameterizations for LES and Reynolds Averaged Navier Stokes Models (RANS) that form the basis for present mesoscale models. Ultimately, the couplingbetween the earth’s surface and the atmosphere in Artic regions should be more faithfully predicted guided by the future field campaigns to be held at Summit.

What significant advance(s) in relation to the IPY themes and targets can be anticipated from this project?
The proposed project will advance the knowledge necessary to evaluate the consequence of climate change, at the same time it addresses key questions in the atmospheric boundary layer at an ideal site for such experiments. The experiments planned during the IPY will pave the way to upgrade the current observations at Summit to a prospective International Summit Greenland Environmental Observatory (c.f. EoI by R. Bales). The proposal offers the basic information for understanding atmospheric turbulence and surface-atmosphere coupling. If the long-term future observatory is realized, such an organization will become the only observational site for monitoring a vast range of atmospheric characteristics far from strong emmission sources.

What international collaboration is involved in this project?
To date, the Summit projects encompass collaborations among US, Danish, Swiss, French and German groups. Other nations are expected to join.

FIELD ACTIVITY DETAILS

Geographical location(s) for the proposed field activities:
Summit, Greenland ice sheet (72° 35' N, 38° 27' W, 3,203 m.a.s.l.), i.e. the same site as GISP Summit.

Approximate timeframe(s) for proposed field activities:
Arctic: April/2007 – August/2008            
Antarctic: n/a

Significant facilities will be required for this project:
For the period April to August monthly flight with C130 USAF with additional charters from Greenland Air. There is also a plan to construct a road from Sondrestromfjord to Summit by Danish Polar Centre.

Will the project leave a legacy of infrastructure?
The project will be continuing a legacy of measurements and international cooperation. Measurements during IPY will contribute to understanding of the Arctic atmosphere. Future research will build on this knowledge. The site and existing buildings can be made a permanent International Summit Greenland Environmental Observatory (c.f. EoI by R. Bales).

How is it envisaged that the required logistic support will be secured?

The above logistics apply for various levels of the entire logistic activities.

Has the project been "endorsed" at a national or international level?
The project is approved and supported by the Swiss IPY Committee as well as the Swiss Commission for Polar Research. This project has an endorsement from US NSF. European groups collaborate for last three years with a centre at the Danish Polar Center.

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
Summit has been active for various projects since 1999. The IPY helps bring these projects into better coordination among ongoing projects, and provides a chance for other groups to join. This is a complementary project to EoI R. Bales et. al. and A. Ohmura et. al..

How will the project be organised and managed?
An International Steering Committee (ISC) is proposed under which Logistics and Scientific Groups will coordinate activities. The project management plan will be developed in conjunction with the EoIs of R. Bales et. al. and A. Ohmura et. al..

What are the initial plans of the project for addressing the education, outreach and communication issues outlined in the Framework document?
The project will involve many graduate and undergraduate students. It will take advantage of the station's excellent communicational and computational facilities. Knowledge and information developed at Summit will be transferred to the science community, decision-makers, and the public. Products will include web-based data and information systems.

What are the initial plans of the project to address data management issues (as outlined in the Framework document)?
Data obtained from the project will be archived and distributed via the www. There will be standard data quality control and data management organized according to international standard format for easy access.

How is it proposed to fund the project?
Swiss National Science Foundation and research funds from the Swiss Federal Institute of Technolgy Lausanne (EPFL).

Is there additional information you wish to provide?
The present proposal focuses on the Summit field site. For evaluating the stability of the entire ice sheet, it is necessary to investigate lower regions of accumulation area and the entire ablation area for which a separate proposal is written. The present project is prepared also with co-ordination with this group. The applicant's group has one of the most advanced ice sheet dynamics model already. The proposal is prepared under a full coordination with others intending to work at Summit, especially Prof. Roger Bales and Prof. Atsumu Ohmura.

PROPOSER DETAILS

Professor, Dr. Marc Parlange
Institute for Environmental Science and Technology, EPF Lausanne
GR B2 417
Station 2
CH-1015 Lausanne
Switzerland

Tel: +41 21 693 6391
Mobile:
Fax: +41 21 362 5197
Email:

Other project members and their affiliation

Other Information