Expressions of Intent for International Polar Year 2007-2008 Activities

Expression of Interest Details

PROPOSAL INFORMATION

Improved Treatment of Clouds in Arctic Climate Models  (Cloud/Radiation Interactions)

Outline
Current climate models provide inadequate treatment of cloud/radiation interactions, leading to large model-to-model discrepancies. The goal of our research is to improve the treatment of cloud/radiation interactions in climate models by combining expertises in cloud microphysics parameterisation, light scattering, and radiative transfer modelling, and thus to enhance the understanding of physical processes required for better prediction. For ice clouds and mixed-phase clouds (MPCs) our research will contribute significantly to assess the impact of ice crystal shape on radiative warming and cooling rates. Available data. So far we have used data from the Surface Heat Budget of the Arctic Ocean (SHEBA) experiment (1997/1998) and from the North Slope of Alaska Atmospheric Radiation Measurement (ARM) site. In particular, we use knowledge about cloud microphysical properties including phase and particle size distribution obtained from cloud radar and lidar instruments to test and improve the treatment of cloud/radiation interactions in the MM5 atmospheric model. Proposed work. Since limited cloud data hampers our research, we propose to conduct measurements in clouds with a Cloud Particle Imager (CPI) and a 4-pi radiometer on a tethered balloon. The proposed measurements will provide necessary input for modelling optical properties of clouds, which in turn will allow us to validate our radiative transfer models against simultaneous light measurements, assess the impact of clouds on UV and PAR doses, and determine the extinction-to-back scattering ratio (EBR) in the polar region. Accurate knowledge of the EBR is a prerequisite for retrieving cloud and aerosol information from lidar data. Our in situ cloud data will be made available to the CALIPSO validation team, and thus contribute to the validation of CALIPSO data for the polar region. Due to the limited observational data available our analyses of errors in both microphysics and radiative transfer will be restricted. Thus, when new cloud data become available, we will conduct a number of sensitivity studies in a high-resolution weather prediction model. Our findings will be used to improve the treatment of cloud/radiation interactions in the numerical model. New knowledge gained from the weather prediction model will be used to improve the parameterisation of microphysical and radiation properties in coarser scale climate models. In particular, the group has access to the Bergen Climate Model, which will be used as a test bed in this case. The new cloud data will offer a unique opportunity for improving our understanding of atmospheric physics at high latitudes.

What significant advance(s) in relation to the IPY themes and targets can be anticipated from this project?
The main advance of this project is the provision of unique data about the microphysical properties of clouds in the Arctic, which will significantly enhance the treatment of ice clouds and MPCs in arctic climate models.

What international collaboration is involved in this project?
The research team includes members from Norway, Sweden, and USA.

FIELD ACTIVITY DETAILS

Geographical location(s) for the proposed field activities:
The field activity will take place in Kongsfjorden, Ny-Ålesund, Svalbard.

Approximate timeframe(s) for proposed field activities:
Arctic: May-October, 2007      May-October, 2008      
Antarctic: n/a

Significant facilities will be required for this project:
Snow terrain vehicles will be required.

Will the project leave a legacy of infrastructure?
No.

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

Has the project been "endorsed" at a national or international level?
The ongoing research activity aimed at improving the treatment of clouds in climate models is supported by the Norwegian Research Council.

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

It is a new autonomous proposal that is linked to an ongoing research activity supported by the Norwegian Research Council.

How will the project be organised and managed?
The project will be organised and managed as a free-standing project.

What are the initial plans of the project for addressing the education, outreach and communication issues outlined in the Framework document?
Such plans will be included in the full proposal.

What are the initial plans of the project to address data management issues (as outlined in the Framework document?
Such plans will be included in the full proposal.

How is it proposed to fund the project?
Funding will be sought through national funding agencies.

Is there additional information you wish to provide?
No.

PROPOSER DETAILS

Pro Jakob J. Stamnes
Department of Physics and Technology
Allégt. 55
Bergen
N-5007
Norway

Tel: +47 55 58 28 18
Mobile: +47 95 77 00 66
Fax: +47 55 58 94 40
Email:

Other project members and their affiliation