Department of Civil
and Environmental
Engineering
Title:
Dynamical Climate Downscaling for Tropical Regions
of Australia and Neighbouring Countries
Speaker:
Dr. John McGregor, Senior Principal Research Scientist,
CSIRO Marine and Atmospheric Research,
Aspendale, Melbourne, Australia
Organizers:
Department of Civil & Environmental Engineering (CEE)
Tropical Marine Science Institute (TMSI)
Centre for Hazards Research (CHR)
Target Audience:
All are welcome. Admission is free.
Date:
Thursday, 29 September 2011
Time:
3.00 pm - 4.00 pm
Venue:
Seminar Room EA-06-02
Faculty of Engineering, NUS
General Enquiry:
Mr. Yong Tat Fah,
Tel: 65162149
Contact Person:
Email: ceeytf@nus.edu.sg
Dr. LIONG Shie-Yui
Tel: 65163081
Email: tmslsy@nus.edu.sg
Synopsis:
Coupled atmosphere-ocean Global Climate Models (GCMs) are increasingly being used to
simulate future climate change. However, they usually have a fairly coarse resolution of
100-200 km, which is too coarse to resolve steep orography, complex land-use or smallscale coastal features. To simulate climate at smaller length scales, dynamical downscaling
may be used whereby a regional climate model is driven in some manner by a coupled
GCM. For the past 10 years, downscaling at CSIRO has been performed with a variableresolution global atmospheric model, the Conformal-Cubic Atmospheric Model (CCAM). It
has become possible to run models, such as CCAM, downscaled from a variety of host
models and scenarios.
A number of simulations will be shown over the Australia, concentrating on the monsoonal
region. These include 140-year simulations at 200 km, 60 km and 20 km resolution, driven
by the bias-corrected sea surface temperatures (SSTs) and sea-ice distributions of the
CSIRO Mk 3.5 coupled GCM, as well as for five coupled host GCMs from the IPCC Fourth
Assessment: GFDL2.1, GFDL2.0, HadCM2, ECHAM5 and Miroc-Medres, all for the A2
emission scenario. A digital filter technique is employed to preserve the large-scale patterns
of the intermediate coarser CCAM simulations. The downscaled simulations provide an
ensemble of regional climate change scenarios.
An ensemble of downscaled CCAM simulations has also been performed at resolutions of
60 km and 14 km over Southeast Asia. The various simulations are compared for their
present-day climatology, their monsoonal behaviour and for their climate change response.
In addition, downscaling simulations are being performed at higher resolution over selected
Pacific island countries as part of the Pacific Climate Change Science Program. The biascorrection of the SSTs from the host GCMs, allows the simulations to better capture
present-day trade winds and tropical circulations.
About the Speaker
Dr. John McGregor is a Senior Principal Research Scientist in Melbourne at the CSIRO
Marine and Atmospheric Research, Centre for Australian Weather and Climate Research.
He obtained his Ph. D. in Applied Mathematics from Monash University in 1974. John has
been the main developer of several weather and climate models during his career, including
the ARPE weather forecasting model, used operationally for some years by the Bureau of
Meteorology, and the LADM model, used for research into pollution and wind field
modelling. Since the early 1990s he has concentrated on regional climate modelling, being
one of the pioneers in that field. He has acquired a great deal of experience, first with the
one-way nested modelling approach of DARLAM. More recently, John has developed the
innovative Conformal-Cubic Atmospheric Model (CCAM) variable-resolution global
model.
The Speaker is in Singapore on an invitation from the Tropical Marine Science
Institute and the Integrated Sustainability Solutions (ISS) Research Cluster of NUS.
Visitors may park their cars at the Cash-Card operated Car park 2A opposite Engineering
Block E3A.
EA-06-02