Final Technical Report - weADAPT

4 Characterization of Current Climate and Scenarios of Future Climate
Change
4.1 Activities Conducted: Development of high resolution regional climate scenario for
the lower Mekong River region
4.2 Description of Scientific Methods and Data
This research had developed high resolution climate scenario for Southeast Asia
region. The simulated climate scenario provides high resolution daily climate data at the
resolution of 0.1 degree (approx. 10km), which would then be used as input for
hydrological and crop model.
The climate model used for this simulation is Conformal Cubic Atmospheric
Model (CCAM), which is the second-generation regional climate model developed
specifically for Australasian region by the CSIRO Division of Atmospheric Research in
Australia. (McGregor et al, 1998) CCAM has also been evaluates in several international
model inter-comparison exercises to be among the best climate model for Asian region.
The model uses the principle of stretched coordinate of a global model instead of uniform
latitude-longitude grid system, which helps minimizing
‘bouncing’ effect at the boundary. This technique has
advantage over the downscaling technique, which has
been proven to be unable to give accurate result for the
region. The simulation process in this “stretched grid
technique” will make calculation for the specific area at
high resolution while calculate the area further away at
lower resolution in order to save computing time. Such
technique has an important advantage that it can
Figure 8: Stretched-grid with
produce very high-resolution climate projections for controlled boundary in the study area
the target study area, the output resolution was set at 0.1 degree (about 10 km). The
CCAM model runs for 18 vertical levels including the stratosphere. It also allows for
other features, such as land and sea surfaces surface land form and land cover be varied
and climate be simulated under different combinations of atmospheric and land surface
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