METEOROLOGICAL DISASTERS IN MALAYSIA

Fredolin Tangang Climate and Ocean Analysis Laboratory

School of Environmental and Natural Resource Sciences, Faculty of Science & Technology,

NATIONAL UNIVERSITY OF MALAYSIA

The Frist International Workshop on Prevention and Mitigation ofMeteorological Disasters in Southeast Asia, March 3-5, 2008, Kyoto, Japan

Three Flood Events in Eastern Peninsular Malaysia

• The 2006/2007 Flood– On the roles of the northeast cold surge, the Borneo vortex, the

Madden-Julian Oscillation, and the Indian Ocean Dipole during the worst 2006/2007 flood in southern Peninsular Malaysia, Tangang et al. (2008, Submitted to GRL)

• The 9-11 December 2004 flood– Numerical investigation of an extreme rainfall event during a

period of 9-11 December 2004 over the east coast Peninsular Malaysia (Juneng et al. 2007, Meteor. Atmos. Phys., 98, 81-98)

• Typhoon Vamei (26-27 Dec 2001)– Tangang FT, Juneng L and C.J.C Reason (2007). MM5

simulated evolution and structure of tropical cyclone Vamei (2001), Advances in Geosciences Vol.9, 191-207.

On the roles of the northeast cold surge, the Borneo vortex, the Madden-Julian Oscillation, and the Indian Ocean Dipole

during the worst 2006/2007 flood in southern Peninsular Malaysia

Fredolin T. Tangang, Liew Juneng and Ester SalimunClimate and Ocean Analysis Laboratory, Universiti

Kebangsaan Malaysia, MalaysiaPN Vinayachandran

CAOS, Indian Institute of Science, IndiaYap Kok Seng

Malaysian Meteorological Department, MalaysiaC.J.C. Reason

University of Cape Town, South AfricaSK. Behera

FRCGC, JAMSTEC, JapanT. Yasunari

HyARC, Nagoya University, Japan(submitted to GRL January 2008)

The 2006 / 2007 Flood

•Major & worst ever (at least in 100 years) flood

•Duration > 1 month

•No. of Evacuees > 200,000 people

•Economic losses ~ Government MYR1.5 billion (total losses could be more)

Episode 1

(mm

/hr)

Episode 2 Episode 3Flood 1st wave

TRMM area-averaged Precipitation Rate

Flood 2nd wave

Flood Flood ““1st Wave1st Wave”” ((19-31 December 2006)

No of evacuees = 104,023

24/12/2006

27/12/2006

25/12/2006

25/12/2006

Flood Flood ““22ndnd WaveWave”” ((11-31 January 2007)

No. of evacuees = 109,259

The flood was very unusual

• During northeast (winter) monsoon, the usual flood location is in the northeastern region of Peninsular Malaysia

• The flood occurred during peak of 2006/2007 El Nino year --- we should have been experiencing drier period

• The rainfall episodes were so severe

Usual flooded area

2006/2007 Flood

El Nino 2006/2007 was at its peak

[El Nino – La Nina ] Composite

Juneng & Tangang,Clim. Dyn., 2005)

Normal

Drier

Rainfall Distribution on 18-21 December 2006

1 Segamat 66 239 162 48 515 1872 Air Panas 98 477 149 58 782 2053 Labis 96 301 130 23 550 2054 K.Penghulu Chaah 103 251 84 9 447 2325 Ladang Chan Wing 92 245 101 2 440 2386 Empangan Sembrong 120 193 70 23 406 2087 Bandar Kluang 58 251 101 21 431 2438 JPSLarkin 80 292 66 23 461 227

Purata Jumlah Hujan Bagi Bulan Disember

Jumlah hujan 4 hari (mm)Bil Nama Stesen 18/12/2006 19/12/2006 20/12/2006 21/12/2006

3.8X

2 X

Dec. Monthly Rainfall

(mm)

4-DayRainfall (mm)

Station Name

Courtesy: DID, Malaysia

11/1/2007 12/1/2007 13/1/2007 14/01/2007

1 Air Panas Segamat 81 204 129 17 431 164

2 Empangan Bekok Batu Pahat 85 237 88 52 462 191

3 SgBekokB77 Segamat 99 247 93 32 471 168

4 Ladang Chan Wing Segamat 110 240 100 19 469 168

5 Ulu Sebol Kota Tinggi 124 290 76 42 532 176

6 Bukit Besar Kota Tinggi 147 234 42 35 458 176

7 Bandar Kluang Kluang 121 182 105 15 423 143

Purata Jumlah Hujan Bagi

Bulan Januari

Jumlah Hujan 4 hari (mm)Bil Nama Stesen Daerah

Rainfall Distribution On 11-14 Januari 2007

3.1X

Jan Monthly Rainfall

(mm)

4-DayRainfall (mm)

Station Name District

2 X

Courtesy: DID, Malaysia

Rainfall in Senai, Johor

Daily rainfall Jan 2007 Average rainfall in JanMaximum rainfall (1975-2006)

Courtesy: MMD

Ave. rainfall in Jan

DATE

Rai

nfal

l

1st

2nd 3rd

50oE 100oE 150oE 160oW 110oW 60oW

50oS

25oS

0o

25oN

50oN SWM (Late May to Sept)

NEM (Nov to March)

INDIAN OCEAN

PACIFC OCEAN

Monsoon & Dominant Modes of Climate Variability

Indian Ocean Dipole (IOD), El Nino-Southern Oscillation (ENSO) ----Interannual oscillation (2-7 years)

Madden-Julian Oscillation (MJO) – intra-seasonal oscillation (20-60 days)

What caused the extreme rainfall episodes?

• Very crucial to understand roles of various motion systems– Cold surges– Borneo vortex

• Roles of Elevated Terrains• Roles of MJO, abrupt termination of IOD

1st Episode 2nd Episode

3rd Episode After 2nd Episode (no rainfall)

Weak cross-equatorial flow No or weak

Borneo Vortex

00Z 17 Dec 2006, 850hPa wind (1st Episode, Extreme rainfall over S. Peninsular Malaysia)

18 UTC 30 December 2006 (No rainfall over Peninsular Malaysia)

Strong vortex

Roles of MJO in modifying the synoptic-scale circulation

First Episode

1. MJO response modified the circulation and prevented the counter-clockwise turning of northeasterly wind over southern SCS2. Formation of Borneo vortex was inhibited3. Direct penetration of northeasterly winds to southern Peninsular Malaysia and Sumatra4. Terrain blocking effect caused low-level convergence

Second episode

(No rainfall)

Third Episode

Abrupt termination of IOD in December 2006 also played a role

ily

30d60d OLRA Daily TMI SSTA 200 - OLR

SSTA

Precip. Anomaly

SSTA

Precip. Anomaly

MM5 Simulation of 1st

Episode

Model:PSU/NCAR MM5Data – FNL, TRMM,

USGS, SST (Reynold et al. 2002)

2 DOMAIN -110x110 (45km), 142x142 (15 KM)

24 sigma-levels

Parameterization schemes

• Parameterization schemes –

– Cumulus parameterization : Betts Miller – Explicit moisture : Simple Ice – Planetary Boundary Layer : MRF

Simulated Acc_Rainfall

MM5 able to produced 90% of the accumulated rainfall However, produced high rainfall at northern Sumatra region.

MODEL-500mmTRMM – 550mm

A A’

Wind Field

Flattened TerrainACC_xTERRAIN

Without TerrainTopography plays an

important roles in low-level convergence over the region

The intensity of the heavy rainfall over Johor and northern Sumatra decreases significantly

Most of the rainfall distributed over the coastline of east coast Peninsular Malaysia and over sea.

Vertical Cross Section

• Vertical cross section: AA’-humidity (contour)-vertical component

win• Terrain provides forcing

for moist air lifting.• Wind bring moist from

SCS

09z17dec2006 06z18dec2006

05z19dec2006 12z20dec2006

Terrain Removed

• No upward movement• Indicate topography

played role in strong convective activities during the flood event.

09z17dec2006 06z18dec2006

05z19dec2006 12z20dec2006

Numerical Case Study of An Extreme Precipitation Event

In The East Coast Peninsular Malaysia

9 – 11 DEC 2004

Juneng, L., F.T. Tangang and C.J.C. Reason (2007). Numerical Investigation of an Extreme Rainfall Event during a Period of 9-11 December over the East Coast Peninsular Malaysia. Meteor. Atmos. Phys., 98, 81-98.

Introduction

>600 mm

9-11/12/2004 Accumulated rainfall[Source: TRMM 3B42RT]

• 9-11 December 2004 significant rain spell.

• Wide spread heavy rainfall across several states in northern Peninsular

• 3 days rainfall near Kuantan summed to >600mm

• Area averaged rainfall (3 hourly) shows that the heaviest rain rate occurred at early 10 December

Introduction

850 hPa UV (00 UTC 10/12/2004)

20 m/s

• GMS satellite IR image shows thick cloud cluster over Peninsular Malaysia and also Sumatera.

• Surface wind analyses of NCEP/FNL shows strong easterly jets and a low level vortex

• The low level vortex drifted from the northern Borneo into the equatorial South China Sea and then enhanced by the cold surge winds

• The westward propagating system reached Peninsular around 00 UTC 10/12/2004

PSU/NCAR MM5 Model Setup

• Betts-Miller (Cumulus)• Blackadar (PBL)• Schultz (Microphysics)• CCM2 (Radiation)

• NCEP FNL at 1.0°×1.0°• SST: RTG SST at

0.5°×0.5°

• Start at 00 UTC 9 December 2004

• 72-hr Integration.

Physics

Initial/Boundary Conditions

Model Time

15 km

45 km

Land-Use• USGS 25-categories

dataset.

Validation (Precipitation)

~ 600mm

~ 450 mm • The simulation was able to reproduce the rain episode with reasonable accuracy.

• The spatial pattern of the rainfall particularly the maximum rainfall center is correctly simulated.

• The 9-11 December accumulated rainfall summed to 450mm and is ~70% of the TRMM estimation.

• Rain cluster in north eastern sumatra is also captured in the simulation.

simulation

TRMM

Validation (low level wind)

~24m/s

• The low level vortex is successfully simulated in the model.

• The point of landfall correspond well in both simulation and the FNL analysis.

• However the propagation is slightly behind that of NCEP/FNL (~4 hours).

• The wind velocity to the north of the vortex center is slightly greater (24m/s).

~20m/s

simulation

NCEP Analysis

Numerical Case Study of Near Equatorial South China Sea Typhoon Vamei 2001

Tangang FT, Juneng L and C.J.C Reason (2007). MM5 simulated evolution and structure of tropical cyclone Vamei (2001), Advances in Geosciences

Vol.9, 191-207.

Introduction

Model Setup (PSU/NCAR MM5)

• Landuse: USGS 25 categories• Cumulus: Kain-Fritch• Explicit Moisture: Schultz• PBL: Blackadar• 2 Domain: D1 is used for analysis

nudging to provide enhanced BC for D2 (15km).

• D1 start at 00 UTC 26 December 2001. D2 start 12 hours later at 12 UTC 26 December 2001 (No artificial vortex).

Simulation Validation

0 6 12 18 24 30 360

5

10

15

20

25

30

35

40

45

50

Time into model integration (hour)

Max

imum

Sur

face

Win

d (m

/s)

-1 5 11 17 23 29 35970

975

980

985

990

995

1000

1005

1010

Time into model integration (hour)

Cen

tral P

ress

ure

(mb)

Simulation Validation

Hydrometeor ( 05 UTC 27 December 2001 )

98E 99E 100E 101E 102E 103E 104E 105E 106E 107E 108E 109E 110E-4N

-3N

-2N

-1N

0N

1N

2N

3N

4N

5N

6N

7N

8N

98E 99E 100E101E102E103E104E105E106E107E108E109E110E-4N

-3N

-2N

-1N

0N

1N

2N

3N

4N

5N

6N

7N

8N

GMS IR (Kochi University Archive)

MM5 Simulation (made of mixing ratio of 5 water species)

A A’

B B’

C C’

D D’

Vertical Structure

.001 .002 .004 .008 .016 .032 .064 .128 .256 .512 1.024 2.048g/kg

Vertical section across the vortex center at 04 UTC 27/12/2001

Shade: Rainwater mixing ratio.

Contour: Temperature.

Vector: Wind parallel to the plan.

Vertical Structure Equivalent potential temperature at 04 UTC 27/12/2004

Section across vortex center (The line indicate 273K isotherm)

A 3D view. Iso-surface of 354 K.

340 342 344 346 348 350 352 354 356 358

θe (K)

Sensitivity experiments

0 6 12 18 24 30 36975

977

979

981

983

985

987

989

991

993

995

997

999

1001

1003

1005

1007

1009

1011

1013

1015

MODEL HOUR

CE

NTR

AL

PR

ES

SU

RE

(mb)

CTRL EXPLHR EXPSFCFLUX EXPSFCFRIC EXPZONALSST EXPMERIDIONALSSTEXPTERR

Summary

• The rainfall episodes that caused the two floods were of different mechanisms

• First Flood event: Cold surges, Borneo Vortex, MJO, IOD and terrain played roles

• Second flood event: Cold surge and intensification of Borneo vortex. Borneo vortex drifted westward and interacted with local terrain.

• Third flood: Similar to the second but the Borneo vortex evolved into a typhoon

26-27 February 2008 (~130 participants, ~40 oral papers (50% foreign countries– Australia, Canada, India, Indonesia, Japan, Thailand, UK)

Roundtable Discussion

Climate Research @ National University of Malaysia

• Climate Change is one of six research niche areas

• Recently established a climate research center --- Research Center for Tropical Climate Change (IKLIM)

• 16 - 20 faculty members, 30 graduate students

Ongoing Projects (2007-2009/10)

Climate and Ocean Analysis Laboratory

• Members (2 faculty members from this school + several affiliated members from school of mathematical sciences)

• 20 students• Computing facilities (2 linux clusters,

several workstations and PC working terminals)

• Oceanographic instrumentations