HR: 1340h
AN: H33B-1261    [Abstracts]
TI: Climate Model Simulations of Point Potential Evaporation
AU: * Kirono, D
EM: dewi.kirono@csiro.au
AF: CSIRO Marine and Atmospheric Research, 107-121 Station street, Aspendale, Vic 3195, Australia
AU: Jones, R
EM: roger.jones@csiro.au
AF: CSIRO Marine and Atmospheric Research, 107-121 Station street, Aspendale, Vic 3195, Australia
AU: Bathols, J
EM: janice.bathols@csiro.au
AF: CSIRO Marine and Atmospheric Research, 107-121 Station street, Aspendale, Vic 3195, Australia
AB: This paper examines whether the observed point potential evaporation (Ep) climatology and trends are reproduced in an offline simulation based on Global Climate Model (GCM) output. Ep is a measure of potential evaporation from an area which is so small that the effects of the evaporation on the overpassing air would be negligible. For example, an evaporation pan measures the evaporation at a point, and is too small to modify the temperature and humidity of the passing air when it becomes well mixed. This work is essential to reconcile the difference between observations and model simulations, namely there have been negative trends reported in the recent observed pan evaporation in some regions (e.g. Australia and New Zealand) while there have been positive trends projected in climate model simulated evaporation for the future (e.g. in Australia). In this study, the simulated Ep was calculated using the Complementary Relationship Areal Evaporation (CRAE) model of Morton (1983). The required inputs - air temperature, humidity measures (vapour pressure, dew point temperature, relative humidity) and downward solar radiation at the surface - are obtained from a number of GCMs. The examination of model performance in simulating observed Ep climatology is conducted on a global basis, while that of model performance in simulating observed Ep trends is conducted over the Australian region.
DE: 1620 Climate dynamics (0429, 3309)
DE: 1813 Eco-hydrology
DE: 1843 Land/atmosphere interactions (1218, 1631, 3322)
SC: Hydrology [H]
MN: 2007 Fall Meeting