Abstract

This poster describes a component of a study addressing the affects of land-use change in South East Asia on the regional climate. To date, most tropical climate modelling studies have focused on Amazonia and Africa, leaving a dearth of work within SE Asia. As this region is more strongly affected by maritime conditions and has a very different assemblage of land-use practices, the sensitivity to change may be different to that experienced elsewhere within the tropics.

Specifically, the poster evaluates a new modelling technique developed at Lancaster that robustly identi.es the cyclical and trend characteristics in time-series data. Such characteristics within tropical rainfall data includes the monsoons, short- and longer-term El Niño Southern Oscillation cycles, cycles resulting from Walker cell migration, and longer-term drifts in the climate. The algorithm is called the Dynamic Harmonic Regression (DHR) model, and its ef.ciency in modelling rainfall time-series from sites across SE Asia is evaluated. Interpretation of the strength and periodicity in the disaggregated rainfall data is then made. Implications of these analyses in the evaluation of the accuracy of General Circulation Models (GCMs) in the simulation SE Asian climates is then discussed. The more reliable are the temporal characteristics of GCMs applied to SE Asia, the greater will be the faith attributable to GCM land-use change scenarios.