Sains Malaysiana 42(8)(2013): 1051–1058

Projected Changes of Future Climate Extremes in Malaysia

(Unjuran Perubahan Iklim Ekstrim Masa Depan di Malaysia)

Meng Sei Kwan, Fredolin T. Tangang & Liew Juneng*

Research Center for Tropical Climate Change System, Faculty of Science and Technology

Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor D.E. Malaysia

Diserahkan: 1 November 2011/Diterima: 3 April 2013

ABSTRACT

Mitigating and adapting to the impacts of climate change at regional level require downscaled projection of future climate states. This paper examined the possible changes of future climate extremes over Malaysia based on the IPCC SRES A1B emission scenario. The projected changes at 17 considered, stations were produced by bias correcting the UKMO PRECIS downscaling simulation output. The simulation expected higher probability of rainfall extreme occurrences over the west coast of Peninsular Malaysia during the autumn transitional monsoon period. In addition, possible early monsoon rainfall was projected for certain stations located over East Malaysia. The simulation also projected larger increase of warm temperature extremes but smaller decrease of cold extremes, suggesting asymmetric expansion of the temperature distribution. The impact of the elevated green house gases (GHG) is higher on the night time temperature extremes as compared to the day time temperature extremes. The larger increment of warm night frequencies as compared to the warm day suggests smaller diurnal temperature ranges under the influence of higher greenhouse gases. Stations located in East Malaysia were projected to experience the largest increase of warm night occurrence.

Keywords: Bias correction; climate extremes; Malaysia; PRECIS; SRES A1B

ABSTRAK

Tebatan dan adaptasi kepada impak perubahan iklim pada aras rantauan memerlukan penurunan skala unjuran keadaan iklim masa depan. Kertas ini mengkaji kemungkinan perubahan iklim ekstrim masa depan sekitar Malaysia berasaskan senario pancaran IPCC SRES A1B. Unjuran perubahan pada 17 stesen dihasilkan dengan membetul pincang output simulasi penurunan skala UKMO PRECIS. Simulasi menjangka kebarangkalian kejadian hujan ekstrim yang lebih tinggi di sekitar pantai barat semenanjung Malaysia semasa musim peralihan luruh. Perawalan musim monsun turut diunjur bagi sesetengah stesen di Malaysia timur. Simulasi turut mengunjur penambahan tinggi ekstreme suhu panas tetapi pengurangan rendah ekstrim sejuk. Ini mencadangkan kembangan taburan suhu secara tak bersimetri. Impak peningkatan gas rumah hijau lebih tinggi kepada suhu ekstreme waktu malam berbanding dengan suhu ekstrim waktu siang. Penambahan kekerapan malam panas yang lebih tinggi berbanding dengan siang panas mencadangkan pengurangan julat suhu harian bawah aruhan gas rumah hijau yang tinggi. Stesen-stesen di Malaysia timur diunjur akan mengalami penambahan paling tinggi bagi kejadian malam panas.

Kata kunci: Iklim ekstrim; Malaysia; pembetulan pincang; PRECIS; SRES A1B

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*Pengarang untuk surat-menyurat; email: juneng@ukm.my