The Weather Research and Forecasting (WRF) model has been used at convection permitting
resolution (2km) to simulate the future climate of Sydney with a focus on precipitation extremes at
durations from 1 hour to 1 day. Overall, the simulations project temperature increases of 1 to 2K, with
larger increases in autumn and winter compared to spring and summer. In terms of precipitation most
of the domain is projected to see annual increases of up to 40%. These increases occur mostly in
autumn, with little change in summer. Extreme precipitation (higher than 95th percentile) is projected
to contribute a larger proportion of this precipitation total.
While the model can reasonably reproduce medium extremes (like the 95th percentile), annual
maxima precipitation time-series contains significant over-estimation for much of the area of interest.
Given this model limitation, the area averaged Intensity-Frequency-Duration (IFD) curves are
simulated reasonably well at large Annual Exceedence Probabilities (AEP) (50%) and show
progressively larger errors for smaller AEPs. Future projections show rainfall depths increasing for all
durations and AEPs considered here. This future increase is larger for smaller AEPs, but relatively
consistent across durations.
This page is maintaind by Jason Evans |
Last updated 31st January 2013