Microphysics of Antarctic Clouds

Lead Research Organisation: University of Manchester
Department Name: Earth Atmospheric and Env Sciences

Abstract

The largest uncertainties in future climate predictions highlighted by the Intergovernmental Panel on Climate change (IPCC 2007) arise from our lack of knowledge of the interaction of clouds with solar and terrestrial radiation (Dufresene & Bony, 2008).
In Antarctica clouds play a major role in determining the continent's ice sheet radiation budget, its surface mass balance and ozone climatology. However in spite of this there are few in situ measurements of cloud properties, aerosol numbers, Cloud Condensation Nuclei (CCN) or Ice Nuclei (IN) with the main focus being on remote sensing data sets (see the review by Bromwich et al 2012). As a result the skill in climate and forecast models at high latitudes is significantly poorer than at mid latitudes.
In this is project we plan to extend the regions sampled to ones more representative of the Antarctic continent's coastal region. It is in this coastal region that clouds will have the biggest impact on the climate as in the interior of the continent the total cloud cover is less (Lachlan-Cope 2010) and those clouds that exist are more tenuous. To achieve this we will conduct flights from the Halley research
station.

Planned Impact

This study addresses an area in which numerical models of the atmosphere over Antarctic are deficient. The results from this study will be used to develop new cloud parametrizations that can be used in high resolution local forecast model and lower resolution global climate and forecast models. The developers of high resolution models such as the Weather Research and Forecasting (WRF) model and global models such as the UK Met Office unified model will be consulted about the development of the field campaign and will be given access both to any new parametrizations developed. Also the microphysical data sets collected during the project will be made freely available.

The results from this project will be disseminated to the general public by talks, both to schools and to the wider community. Also key results from the project will be posted on the well visited BAS web site.

Publications

10 25 50
 
Description 1. It has been found that Antarctic layer clouds consist mostly of supercooled water with occasional glaciated patches where secondary ice particle production is important
2. The aerosol is dominated by sea-salt, however bio aerosol (a possible ice nucleus) has been detected intermittently
3. New particle production just above cloud seems to occur
Exploitation Route The treatment of Antarctic cloud in large scale models
Sectors Aerospace, Defence and Marine,Energy