Current Research

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Current Research

• By Liew Ju Neng
• Marine Science Program
• School of Environment and Natural Resources
• UNIVERSITI KEBANGSAAN MALAYSIA
• MALAYSIA

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Introduction

• Southeast Asian climate is dominated by monsoon.
  Locally northeast (winter) and southwest
  (summer) monsoon.
• Monsoon Flooding in Malaysia (Nov, Dec, Jan, Feb)
  is common.
• Changes in the large scale monsoon circulation
  (e.g Chase et al 2003, Zhang et al 1997, Hu et al
  2000 etc) is expected to change the regional
  rainfall (pattern, intensity, extremes).

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Synoptic Climatology

• Two most prominent features northeasterly surges
  Borneo Vortices

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Questions

• Are there long term changes in these features?
• If yes? What and how do these changes effect the
  regional rainfall distribution.

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Changes in the synoptic circulation?
A
B
A
A
B
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Is there any spatial changes?

• Averaged vorticity differences between 1962-1982
  and 1983-2007.
• There is a northward shift of the vortices.

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• The northward shift of the vortex center is
  presented in the averaged latitude time series.

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The frequency of vortex occurrence also shows
linear trends
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Possible Changes in the Cold Surge
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The Problem

• Here in Malaysia we observed that the rainfall
  has changed significantly over the pass 50 years.
  

PC1 Malaysian Rainfall Frequencies

• Also, there have been some occurrences of
  high-impact weather system in the region in
  recent decades (not shown).

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The problem (cnt)

• How is this changes related to the changes in the
  synoptic climatology is unknown.
• Forecasting rainfall become more challenging,
  especially the extreme cases.
• Government Is the high-impact weather disasters
  more likely in the future?

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Research Projects (Malaysian Government)

• Two different scopes
• 1) To assist the forecaster using NWP approaches
  (MM5, WRF, CReSS)
• 2) To downscale surface climate using the
  synoptic information and to project possible
  future scenarios (PRECIS, empirical models).

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Approaches

• MM5 V3.7
• WRF(ARW) V2.2
• CReSS (HyARC, Nagoya University)
• PRECIS 1.5.1(UK Met Office) (25km)
• Empirical Methods (ANN, SVD, CCA etc)

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SUMMERY

• Main focus (a) Long term changes of regional
  surface climate (b) NWP
• Other interest Short term interannual
  variability and predictability.
• Look forward to talk to anyone with similar
  interest.