Institute of Environmental and Natural SciencesLancaster University

Land-use change impacts on tropospheric convection and

rainfall in SE Asia

NERC PhD studentshipOctober 2001

Southeast Asia and the west Pacific experience the most intense large-scale convection on theplanet. This convection is central to tropospheric circulations - such as the Hadley cell, the Walker

circulation, and the inter-annual El Niño Southern Oscillation (ENSO) in the Walker circulation.The convection is also important in determining the tropical tropopause and, hence, the transport

of water vapour and trace gases into the stratosphere. Lastly, the convection will act as anefficient pump, feeding short-lived chemical compounds into the upper tropical troposphere,

where they may impact atmospheric chemistry on the regional scale.

The UK universities Global Atmospheric Modelling Programme (UGAMP) utilises theMeteorological Office 'Unified Model' (UM) for a wide variety of studies into climate and

atmospheric chemistry. The UM is itself composed of several sub-models, including surfacetopography, a surface-processes model, and a parameterised convection scheme.

This project will, first, assess the results of the modelled climate of SE Asia given the currentmodel set-up - through comparison with measurements of convective cloud and rainfall time-series in particular. Lancaster's DHR-model, a new recursive interpolation, extrapolation andsmoothing algorithm for non-stationary time-series, will be used to aid this comparison. The

sensitivity of the UM to changes in the surface sub-models, in the light of hydro-climatic and land-use data collected in the region, will then be tested. Finally, the impact of large-scale, land-use

change on the model climate will be studied, with particular emphasis on changes in rainfallregime and tropospheric convection.

The research will involve running the Meteorological Office 'Unified Model' on a supercomputer atLancaster (or MCC) and fieldwork in Malaysia and/or Thailand to examine rainfall and land-use

patterns (in association with the Royal Society Rainforest Research Programme). The project is suitable for graduates with degrees in Environmental Science, Meteorology, Geography,

Civil/Environmental Engineering, Physics or Mathematics.

For further information and application forms, please contact Mrs Sue Taylor, the postgraduateadmissions secretary (sue.taylor@lancaster.ac.uk, tel: 01524 - 593968, Environmental Science,

Lancaster University, Lancaster LA1 4YQ) or the supervisors Dr A. Robert MacKenzie(r.mackenzie@lancaster.ac.uk) and Dr Nick A. Chappell (n.chappell@lancaster.ac.uk).