International Seminar On Climate Variability, Change and Extreme Weather Events

26-27 February 2008, Bangi, MALAYSIA

Regional Climate Change over Southeast Asia Region

Mohan Kumar Sammathuria, Ling Leong Kwok & Wan Azli Wan Hassan

Malaysian Meteorological Department

Ministry of Science, Technology & Innovation, Malaysia

SCOPE

• Introduction

• Present Climate (1961-1990)

• Future Climate (2071-2100)– Mean Temp (annual & seasonal) Anomaly– Mean Precip (annual & seasonal) Anomaly– Seasonal Mean Wind Anomaly

• Concluding Remarks

PRECIS 50 kmPRECIS 50 km

GCMs to

Regional Adaptive Responses:

Modelling Path

GCMs to

Regional Adaptive Responses:

Modelling Path

Projected climate change depend on illustrative scenarios (storylines) of greenhouse gases

emissions: Special Report on Emission Scenarios (SRES)

Based on different plausible pathways of future:

development of the world

population growth and consumption patterns

standards and life style of living

energy consumption & energy sources (e.g. fossil fuel usage)

technology change

land use change

Four Marker IPCC’s SRES Future Emission Four Marker IPCC’s SRES Future Emission ScenariosScenarios

A qualitative description of the SRES scenarios

The driving model HadCM3 has predict climate change (global temperature rise) arising from each of the four IPCC’s SRES future emissions scenarios

The driving model HadCM3 has predict climate change (global temperature rise) arising from each of the four IPCC’s SRES future emissions scenarios

~5.0oC

~2.0oC

IPCC AR4

B1: 1.8oC (1.1-2.9)

B2: 2.4oC (1.4-3.8)

A2: 3.4oC (2.0-5.4)

A1FI: 4.0oC (2.4-6.4)

~5.0oC

~2.0oC

IPCC AR4

B1: 1.8oC (1.1-2.9)

B2: 2.4oC (1.4-3.8)

A2: 3.4oC (2.0-5.4)

A1FI: 4.0oC (2.4-6.4)

PRECIS• Providing REgional Climates for Impact Studies• High-resolution limited area model driven at its lateral and sea-

surface boundaries by output from HadCM• PRECIS runs on Linux PC (horizontal resolutions: 50 x 50 & 25 x 25

km).• Needs data for the selected domain on lateral boundary conditions

(LBC) from the driving GCM (e.g., HadCM3/ HadAM3) and the associated ancillary files (e.g., sea surface temp, vegetation, topography, etc).

• Hadley Centre, UK has been providing PRECIS as well as the driving data to several regional groups.

• Baseline (1961-90), A2 & B2 scenarios (2071-2100). Reanalysis-driven runs provide comprehensive regional data sets representing current conditions, which can assist model evaluation as well as assessment of vulnerability to current climate variability.

• Ensembles to estimate model-related uncertainties.

PRECIS resolution 0.44° x 0.44°

HadCM3 resolution 2.5° x 3.75°

Orography Resolution

PRECIS Runs at MMD• LBCs derived from HadAM3P. HadCM3 provided SST as boundary

conditions for HadAM3P.• A2 & B2 scenarios runs of PRECIS performed consecutively on a PC.• PRECIS runs on Linux PC (horizontal resolutions: 0.44° x 0.44°)• The LBCs have a length of 31 years, and are available for Baseline

(1961-90), A2 & B2 scenarios (2071-2100), with the sulphur cycle.• The basic parameters analyzed are the mean surface (1.5 m) temp and

total precip.• The precip & temp obs data (CRU20, 1961-90) is used to validate

model performance in simulating current climate.• The analysis comprised of both annual mean and seasonal mean for

DJF, MAM, JJA and SON.• To detect possible atmospheric circulation change during monsoon

periods (DJF & JJA) in future climate, the seasonal mean 850 hPa wind for the lower emission scenario (B2) was analysed.

PRECIS captures important regional

information on summer monsoon rainfall missing

in its parent GCM simulations

PRECIS performs reasonably well too on

winter monsoon rainfall compared to its parent

GCM simulations

PRECIS Simulations of Present Climate (1961-1990)Mean Annual Cycles of SEA Rainfall and Temperature

0

1

2

3

4

5

6

7

8

9

10

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Months

Ra

infa

ll (m

m/d

ay

)

23

23.5

24

24.5

25

25.5

26

26.5

27

27.5

28

Te

mp

era

ture

(C

)

Observed ppt (1961-90)

Baseline ppt (1961-90)

Observed temp (1961-90)

Baseline temp (1961-90)

PRECIS Simulations of Future Climate (2071-2100)Mean Annual Cycles of SEA Rainfall and Temperature

0

1

2

3

4

5

6

7

8

9

10

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Months

Ra

infa

ll (m

m/d

ay

)

0

5

10

15

20

25

30

35

Te

mp

era

ture

(C

)

Baseline ppt (1961-90)A2 ppt (2071-2100)B2 ppt (2071-2100)Baseline temp (1961-90)A2 temp (2071-2100)B2 temp (2071-2100)

Mean Annual Temp Anomaly

Continental –– larger +ve anomaly (A2, 3.0-4.5 °C; B2, 1.5-3.0 °C)

Larger anomaly over SCS vs western Pacific in A2

c-S P. Malaysia, Sabah & Sarawak –– Larger +ve anomaly

N-E P. Malaysia –– Smaller +ve anomaly

Maritime –– smaller +ve anomaly (A2, 2.0-3.5 °C; B2, 0.5-1.5 °C)

(A2-Baseline) Mean Seasonal Temperature AnomalyMAM

SON

DJF

JJA

(B2-Baseline) Mean Seasonal Temperature Anomaly

SONJJA

DJF MAM

-7% -12%Precip deficit over maritime SEA

Mean Annual Precip Anomaly

Northern P. Malaysia (A2, 17%; B2, 6%)

Southern P. Malaysia (A2, -3%; B2, -20%) Sabah (A2, -15%; B2, -18%)

Sarawak (A2, 5%; B2, -8%)

  A2 (%) B2 (%)

DJF -5 -21

MAM -21 -24

JJA -8 -13

SON 1 -9

SEA Mean Seasonal Precip

Anomaly

Deficit in most seasons

Larger deficit in B2

(A2-Baseline) Mean Precip (%)

JJA -8%

MAM -21%DJF -5%

SON +1%

(B2-Baseline) Mean Precip (%)

JJA -13%

DJF -21%

SON -9%

MAM -24%

Reg DJF MAM JJA SON ANNUAL

  A2 (%)

B2 (%)

A2 (%)

B2 (%)

A2 (%)

B2 (%)

A2 (%)

B2 (%)

A2 (%)

B2 (%)

PM -15 -31 -9 -18 14 -1 19 9 5 -7

SBH -34 -35 -36 -32 2 -3 2 -9 -15 -18

SRWK -14 -25 9 -2 18 1 11 -4 5 -8

NPM -17 -25 1 -11 38 21 27 18 17 6

EPM -7 -30 -17 -24 17 4 20 9 6 -7

CPM -29 -39 -5 -10 12 5 16 14 1 -5

SPM -19 -37 -6 -20 -7 -25 15 -1 -3 -20

SEA -5 -21 -21 -24 -8 -13 1 -9 -7 -12

Malaysia – NEGATIVE ANOMALY mean precip in DJF

Mean Seasonal Precip

Anomaly

Reg DJF MAM JJA SON ANNUAL

  A2 (%)

B2 (%)

A2 (%)

B2 (%)

A2 (%)

B2 (%)

A2 (%)

B2 (%)

A2 (%)

B2 (%)

PM -15 -31 -9 -18 14 -1 19 9 5 -7

SBH -34 -35 -36 -32 2 -3 2 -9 -15 -18

SRWK -14 -25 9 -2 18 1 11 -4 5 -8

NPM -17 -25 1 -11 38 21 27 18 17 6

EPM -7 -30 -17 -24 17 4 20 9 6 -7

CPM -29 -39 -5 -10 12 5 16 14 1 -5

SPM -19 -37 -6 -20 -7 -25 15 -1 -3 -20

SEA -5 -21 -21 -24 -8 -13 1 -9 -7 -12

Mean Seasonal Precip

Anomaly

Northern P. Malaysia – POSITIVE ANOMALY mean precip in JJA & SON, deficit in DJF & MAM

Reg DJF MAM JJA SON ANNUAL

  A2 (%)

B2 (%)

A2 (%)

B2 (%)

A2 (%)

B2 (%)

A2 (%)

B2 (%)

A2 (%)

B2 (%)

PM -15 -31 -9 -18 14 -1 19 9 5 -7

SBH -34 -35 -36 -32 2 -3 2 -9 -15 -18

SRWK -14 -25 9 -2 18 1 11 -4 5 -8

NPM -17 -25 1 -11 38 21 27 18 17 6

EPM -7 -30 -17 -24 17 4 20 9 6 -7

CPM -29 -39 -5 -10 12 5 16 14 1 -5

SPM -19 -37 -6 -20 -7 -25 15 -1 -3 -20

SEA -5 -21 -21 -24 -8 -13 1 -9 -7 -12

Mean Seasonal Precip

Anomaly

Southern P. Malaysia – deficit mean precip in DJF, MAM & JJA, +ve anomaly in SON

Reg DJF MAM JJA SON ANNUAL

  A2 (%)

B2 (%)

A2 (%)

B2 (%)

A2 (%)

B2 (%)

A2 (%)

B2 (%)

A2 (%)

B2 (%)

PM -15 -31 -9 -18 14 -1 19 9 5 -7

SBH -34 -35 -36 -32 2 -3 2 -9 -15 -18SRWK -14 -25 9 -2 18 1 11 -4 5 -8NPM -17 -25 1 -11 38 21 27 18 17 6

EPM -7 -30 -17 -24 17 4 20 9 6 -7

CPM -29 -39 -5 -10 12 5 16 14 1 -5

SPM -19 -37 -6 -20 -7 -25 15 -1 -3 -20

SEA -5 -21 -21 -24 -8 -13 1 -9 -7 -12

Sabah – largest deficit in DJF & MAM

Sarawak – DJF only

Mean Seasonal Precip

Anomaly

Baseline

Weakening easterly (2.0-3.5 m/s)

Mean Seasonal 850 hPa Wind Anomaly (DJF)

Rainfall Anomaly

Anomaly

Mean Seasonal 850 hPa Wind Anomaly (JJA)

Rainfall Anomaly

Baseline Anomaly

Anomalous easterly comp. (1.5-2.5 m/s)

Concluding Remarks• PRECIS was found able to capture important

regional information on seasonal rainfall which is missing in GCM simulation

• Both A2 & B2 scenarios show an increase in the annual mean temp over SEA during 2071-2100, with A2 shows larger increase in temp

• The SEA land surface annual mean warming is in the range of 1.5-3.0 °C with B2 and 3.0-4.5 °C with A2

• The SEA maritime surface annual mean warming is 0.5-1.5 °C with B2 and 2.0-3.5 °C with A2

Concluding Remarks (cont.)

• Both scenarios show a +ve anomaly of mean annual precip over SEA continent while a -ve anomaly over maritime region

• SEA, at large will experience a deficit in mean annual precipitation for both A2 and B2 scenarios, with B2 giving the larger deficit

• Weakening of the easterly during the winter months (DJF) over the western Pacific region in B2 scenarios indicates a weakening of the NE monsoon in SEA region

• In summer (JJA), the anomalous easterly component winds over the Indian Ocean will tend to enhance the +ve IOD phenomenon

Concluding Remarks (cont.)

This is our preliminary results.More works are needed to obtain

credible climate change scenarios with better certainty…..

Concluding Remarks (cont.)

This is our preliminary results.More works are needed to obtain

credible climate change scenarios with better certainty…..

IPCC’s AR4 employed multi-model means of surface warming for the SRES marker scenarios. Numbers indicate the number of models which have been run for a given scenario. The gray bars at right indicate the best estimate (solid line within each bar) and the likely range assessed for the SRES marker scenarios.RCM (e.g. PRECIS), too, should be driven by multi-model in order to know

the uncertainty range of climate change

IPCC’s AR4 employed multi-model means of surface warming for the SRES marker scenarios. Numbers indicate the number of models which have been run for a given scenario. The gray bars at right indicate the best estimate (solid line within each bar) and the likely range assessed for the SRES marker scenarios.RCM (e.g. PRECIS), too, should be driven by multi-model in order to know

the uncertainty range of climate change

Note:

Multi-Model IPCC AR4

Uncertainty Ranges

B1: 1.8oC (1.1 - 2.9)

A1T: 2.4oC (1.4 - 3.8)

B2: 2.4oC (1.4 - 3.8)

A1B: 2.8oC (1.7 - 4.4)

A2: 3.4oC (2.0 - 5.4)

A1F1: 4.0oC (2.4 - 6.4)

Note:

Multi-Model IPCC AR4

Uncertainty Ranges

B1: 1.8oC (1.1 - 2.9)

A1T: 2.4oC (1.4 - 3.8)

B2: 2.4oC (1.4 - 3.8)

A1B: 2.8oC (1.7 - 4.4)

A2: 3.4oC (2.0 - 5.4)

A1F1: 4.0oC (2.4 - 6.4)

Thank You