CORDEX-SEA Multi-scales Climate Downscaling andSimulations for Impact Assessment
Liew Ju Neng(on behalf of CORDEX-SEA colleagues)
Department of Earth Sciences and Environment
Faculty of Science and Technology
Universiti Kebangsaan Malaysia

15th AOGEO online symposium, 28-30 September 2022

Climate Downscaling and CORDEX-SEA• Local climate projection – facilitate local
CC impact assessment.
• Global > Local scale– cascading ofmodeling processes.
• Uncertainties are introduced at eachmodeling levels.
• Run multiple downscaling simulations andcreate ensemble with uncertainty ranges.
• Practically expensive – multi agencies
collaborations (regional andinternationals)
CORDEX-SEA

RCM(Ultra High Resolution)

The Southeast Asia Regional Climate Downscaling (SEACLID) / CORDEXSoutheast Asia Project
14 Countries, 20 Institutions(http://www.ukm.edu.my/seaclid-cordex)
Courtesy: UKMOCORDEX-SEA Simulation Output• Phase 1 (25 km, CMIP5 driven) > completed in 2017• 18 different GCM/RCM couplet.
• >3500 simulation years.
• > 200TB of raw simulation out.
• Output (selected subset) distributed via ESGF @ https://esgf.llnl.gov/• Phase 2 (5 km, subregions, CMIP5 driven) > completed in 2022.
• Phase 3 (25 km CMIP6 driven) > ongoingSimulations Information

Supported by:in preparing the model forcing fields• Domain covers the whole Peninsular Malaysia (98.44 °E •– 105.61°E, 0.26 °N – 8.76 °N)•• Downscaled 3 CMIP5 GCMs (RCP4.5 & RCP8.5):•
i. EC-EARTH (European’s GCM)
ii. MPI-ESM-MR (German’s GCM)
iii. HadGEM2-ES (UK’s GCM)
• Time slice run: 1970 – 2005, 2011 - 2039, 2040 - 2069,2070 – 2099

RCM used: RegCM-NH version 4.7
Resolution: → 5km × 5km (160 × 190 grids); ↑ 18 levels

All physical settings same as CORDEX-SEA phase 1simulation except:
i. CPS: MIT Emanuel (Land) + Kain Fritsch (Ocean);ii. Land surface scheme: CLM4.5
The changes were in hope to reduce the strong wet bias in CORDEX-SEA phase 1 simulations

Contributed Simulations by MRI Japan(via SOUSEI and TOUGOU)NHRCM05
Ngai et al., 2020

• 3 runs contributed:
i. 5km × 5km (NHRCM05) – whole Malaysia
ii. 2km × 2km (NHRCM02-P) – Peninsular Malaysiaiii. 2km × 2km (NHRCM02-S) – East Malaysia (Sarawak)• RCM used: MRI NHRCM• Forced by MRI-AGCM3.2 (20km × 20km), RCP8.5• Time slice run: 1979 – 2002, 2079 – 2100

NHRCM02-S• NHRCM05 uses modified KainFritsch as its CPS, but NHRCM02 is aconvective permitting simulation.

NHRCM02-P
Result will not be discussed here.

National/Local Projects That
Make Use of CORDEX-SEA
DatasetsImpact of Climate Change on Children (UNICEF)

Malaysia Port Climate Change Assessment• The CORDEX-SEA winds/pressure isused to drive the wave model.
• Rainfall and temperature extremechanges were analyzed to examine
the future physical risk of theinfrastructure investment.

Impact of Climate Change on Oil Palm
• The CORDEX-SEA simulations are used
to examine the changes of climate
optimal for oil-palm growth.

Climate Change Vulnerability Assessment for
Integrated Watershed Management• Changes in future climate extremes are overlayedwith underlying watershed elements (land use,ethnography, socio-economy, ecology andenvironment and hydrology) to determine thevulnerability.

Remarks• Climate change projection information are mostly used ‘qualitatively’.
• Lack of guideline on how the downscaled climate projection
information can be used (sectoral specific).
• In general, lack of synergy between different research communities >
difficulty in communicating data users and providers.
• Required more innovative tools to facilitate communications.

The End