Expressions of Intent for International Polar Year 2007-2008 Activities

Expression of Interest Details

PROPOSAL INFORMATION

Cloud Aerosol Interactions in Mixed Phase Arctic Clouds  (ICE CLOUD)

Outline
The purpose of the project is to use the UK community aircraft the BAE 146 to investigate the microphysics and cloud aerosol interactions in arctic mixed phase (ice and water) clouds. The project will investigate the microphysics of the mixed phase cloud including the droplet formation, the nucleation of ice crystals. The growth of ice crystals by vapour diffusion and riming will be studied and the contribution of secondary ice splinters, for example by the Hallett-Mossop process to the glaciation process. The formation of precipitation will be investigated. Detailed measurements will be made of the composition of Cloud Condensation Nuclei (CCN) and Ice Nuclei (IN) using a low turbulence inlet and filters for later analysis together with an Aerodyne Aerosol Mass Spectrometer. The mass spectrometer will give size resolved composition information of the atmospheric particulate at high time resolution and in real time over the size range of 30 nm to 1 um. This will include the major inorganic ions and organic material, which is thought to pay a key role in the Arctic clouds. Whilst an SP2 instrument will be used to provide detailed information of soot and mineral particles and their state of mixing. These are known to be important IN. The specific aims are: To charcterise the compositon of CCN entering the cloud including organic particulate. To study the cloud droplet residues to establish the activation efficiency of the CCN as a function of their size and composition. To investigate the glaciation process in the cloud as the numbers of primary ice nuclei (dust soot etc) entering the cloud change and as a function of the temperature of the cloud To investigate the growth of the ice particles by vapour diffusion and riming using a SPEC CPI probe to study their habits and size distribution along with a range of instruments to measure cloud droplet size, ice and liquid water contents. To investigate the production of secondary ice particles by the Hallett-Mossop process (which operates between –3C and –6C) and the role of these particles in the glaciation of the cloud. To investigate the role of other secondary ice particle production processes such as evaporation and break-up. To study the precipitation production processes in the cloud via the ice processes and by collision coalescence as a function of the prevailing condition (numbers of CCN, IN temperature etc). To perform modeling studies of the cloud dynamics, cloud microphysics and radiative properties using a Cloud Resolving Large eddy Model to compare with the observations.

What significant advance(s) in relation to the IPY themes and targets can be anticipated from this project?
There is considerable uncertainty over the role of clouds in climate change in Arctic regions. The project will provide much improved information on the nature of cloud microphysics in this area and of the influence of pollution and other aerosol on their microphysics and precipitation production. This should aid the treatment of Arctic Clouds in Global and Regional Models to be improved.

What international collaboration is involved in this project?
This specific project is a UK based but will collaborate closely with complementary studies such as ASCOS etc.

FIELD ACTIVITY DETAILS

Geographical location(s) for the proposed field activities:
The region around Spitsbergen, Greenland and Barents Sea.

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

Significant facilities will be required for this project:
We will piggy back on the BAE 146 aircraft with other projects in this area.

Will the project leave a legacy of infrastructure?
Not specifically from this project

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

This will be provided by FAAM alongside support ofr other projects using the UK aircraft

Has the project been "endorsed" at a national or international level?
Application pending

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 anew autonomous proposal but intends to collaborate with others making measurements of a complimentary bnature on this aircraft and at the surface

How will the project be organised and managed?
Tom Choularton of the School of Earth Atmospheric and Environmental Sciences will manage this project at the University of Manchester. Close association with other projects will be maintained.

What are the initial plans of the project for addressing the education, outreach and communication issues outlined in the Framework document?
The project will educate students and postdoctoral workers in the area of cloud aerosol interaction sin mixed phase clouds helping to produce a new generation of scientists in this key area.

What are the initial plans of the project to address data management issues (as outlined in the Framework document?

How is it proposed to fund the project?
A data base will be maintained in Manchester and data will be archived at the British Atmospheric data Centre for future use by the community

Is there additional information you wish to provide?
None

PROPOSER DETAILS

Pro Tom Choularton
SEAES University of Manchester
Sackville St Building
Manchester
M60 1QD
UK

Tel: 44 61 200 3950
Mobile: no
Fax: no
Email:

Other project members and their affiliation