A climatic-scale precipitation model compared with the UKCIP baseline climate.

This paper describes a limited-area, reduced-process model of the large-scale physics of precipitation developed for predicting over climatic timescales. It represents an intermediate approach between a general circulation model (GCM) and full-physics model of precipitation at high resolutions. The model is designed for application in palaeoclimate modelling, specifically as input to ice-sheet models. The model is used to predict seasonal precipitation for the UK, using sea-surface temperatures, topography, mean wind speed and direction. Modelled data are compared with the United Kingdom Climate Impacts Programme (UKCIP) baseline climatologies for the UK and are shown, for westerly and southwesterly winds, to produce precipitation distributions and magnitudes which are in good agreement with the UKCIP data. The modelled data are much more spatially heterogeneous, reflecting the physical nature of the parameterization of the influence of orography. The model's sensitivity to temperature, wind speed and wind direction and its potential for driving ice-sheet models over long timescales are demonstrated. Copyright © 2000 Royal Meteorological Society [ABSTRACT FROM AUTHOR]