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Factors Influencing the Response of the Factors Influencing the Response of the Maritime Continent Climate to ENSOMaritime Continent Climate to ENSO

Dr. Edvin AldrianDr. Edvin AldrianDirector of Center for Climate Change and Air Quality – BMKGDirector of Center for Climate Change and Air Quality – BMKG

Presented in XV WMO RA V Bali 30 April – 6 Mei 2010Presented in XV WMO RA V Bali 30 April – 6 Mei 2010

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Outline of PresentationOutline of Presentation• The theory of El Nino

• Predictability of the maritime continent

• El Nino dan climate of the maritime continent

• ENSO impact episode

• The role of local sea surface current

• El Nino and Indian Ocean Dipole

• Impact of El Nino on the Climate system

• El Nino and global warming

• Positive and negative impact of El Nino

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• ENSO is the abbreviation of El Niño Southern Oscillation

• The term El Nino means ‘Christ Child’ and was first used by Peruvian fishermen in the late 1800’s to describe the warm current appearing off the western coast of Peru around Christmas time.

• Southern oscillation refers to a seesaw shift in surface air pressure at Darwin, Australia and the South Pacific Island of Tahiti. When the pressure is high at Darwin it is low at Tahiti and vice versa. El Nino, and its sister event – La Nina – are the extreme phases of the southern oscillation, with El Nino referring to a warming of the eastern tropical Pacific, and La Nina a cooling.

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Theory: What is ENSO

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Theory: What is ENSOWhat is ENSO• The El Nino is indicated by the movement of warm water movement of warm water mass

under the surface of ocean from the warm pool warm pool region to the central equatorial Pacificcentral equatorial Pacific

• What is the warmpool region? Is the most warmest equatorial region located in the north of the Papua island and formed after the accumulation of flowing surface warm water in the Pacific Ocean.

• Why the surface water in the Pacific flows?– Due to the earth rotation– Part of the Great Ocean Conveyor Belt– The world ventilation system in the ocean

• Where the water mass in the warmpool ends? The accumulation of that water mass will from geostropically to the Indian Ocean as the Indonesian Throughflow

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Theory: Why is ENSO Predictable?Why is ENSO Predictable?• “… the time averages (monthly and seasonal means) for the tropics

have more predictability. This is because they are largely determined by fluctuations of the seasonally varying boundary conditions of sea surface temperature and soil moisture. Under favorable conditions, they can contribute to the predictability of middle latitudes also.” Shukla, 1981Shukla, 1981

• Atmospheric weather is IN PRINCIPLE IN PRINCIPLE not predictable more than 2 weeks or so;

• Over the tropical oceans, the STATISTICSSTATISTICS of atmospheric weather depends on the sea surface temperature (e.g. Rains over warm water);

• Sea surface temperature CANCAN be predicted by a coupled atmosphere-ocean model if the internal state of the upper tropical ocean in known;

• Skill is likely to be much less in mid-latitudes because the SST determines the statistics in the presence or much variability.

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Climatology of regional rainfallClimatology of regional rainfall► Mainly monsoonalMainly monsoonal► Three distinct rainfall climate regionsThree distinct rainfall climate regions

monsoonalmonsoonal

Semi-monsoonalSemi-monsoonal Anti-monsoonalAnti-monsoonal

Aldrian and Susanto, 2003, Intl J Climatol.

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Interannual variability in Region AInterannual variability in Region A

Aldrian et al, 2007, Theo. Appl. Climatol.

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Interannual variability in Region BInterannual variability in Region B

Aldrian et al, 2007, Theo. Appl. Climatol.

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Interannual variability in Region CInterannual variability in Region C

Aldrian et al, 2007, Theo. Appl. Climatol.

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Wide range SST responses to rainfall in region AWide range SST responses to rainfall in region A

• Weak response in spring, no ENSO influenceWeak response in spring, no ENSO influence• Strong two dipoles in SON (Walker cell)Strong two dipoles in SON (Walker cell)• Role of SPCZ in SONRole of SPCZ in SON

Aldrian and Susanto, 2003, Intl J Climatol.Aldrian and Susanto, 2003, Intl J Climatol.

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Wide range SST responses to rainfall in region BWide range SST responses to rainfall in region B

• Weak response in all season, especially in springWeak response in all season, especially in spring• no ENSO influence and walker cellno ENSO influence and walker cell

Aldrian and Susanto, 2003, Intl J Climatol.Aldrian and Susanto, 2003, Intl J Climatol.

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Wide range SST responses to rainfall in region CWide range SST responses to rainfall in region C

• Weak response in springWeak response in spring• Strong two dipoles in SON (Walker cell) like region AStrong two dipoles in SON (Walker cell) like region A• Role of SPCZ in SON like in region ARole of SPCZ in SON like in region A

Aldrian and Susanto, 2003, Intl J Climatol.Aldrian and Susanto, 2003, Intl J Climatol.

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Skills of monthly rainfall variabilitySkills of monthly rainfall variabilityResponse to ENSO Response to ENSO

Variability in Variability in comparison to comparison to observationsobservations(correlation values)(correlation values)

•Negative responses Negative responses to NINO3 SSTto NINO3 SST•Significant in MJJASSignificant in MJJAS(similar to Hendon, (similar to Hendon, 2003)2003)

•Strong responses Strong responses in Region A and Cin Region A and C•Spring is the least Spring is the least responsive seasonresponsive season•ECHAM4 responds ECHAM4 responds well to ENSOwell to ENSO

Aldrian et al, 2007, Theo. Appl. Climatol.

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The

Indo

nesi

an

The

Indo

nesi

an

Thr

ough

flow

Thr

ough

flow

110°E 115°E 120°E 125°E 130° 135°E

10°S

5°S

0°

5°N

sill ~680 m

101.7

4.5 4.3

8

1.5

Mindanao Eddy

Halmahera Eddy

Arus termoklin Pasifik UtaraArus termoklin Pasifik selatanArus permukaan laut Jawa

Java

Flores

Timor

Banda

Seram

Mak

assa

r

Sulawesi

MalukuHalmahera

Lom

bok

Dewakang

Sill

Samudra Indonesia

Samudra Pasifik

Sulaw

esi

Kalimantan

Java

Timor

Australia

ARUS MASUKMakassar (8 - 9 Sv)Jalur timur (1 Sv?)

Lifamatola (1.5 Sv)

KELUAR: Timor, Ombai, Lombok7.3 - 10.7 Sv (rerata 9 Sv)

1.8 - 2.3 Sv (rerata 2.1 Sv)

arus lapisan termoklin

arus dalam680 m Celah Makassar

La

Nina~

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ENSO and ocean: Climate

Normal conditionEl Nino conditionLa Nina condition

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Decadal signals of the maritime continent(Aldrian and Djamil 2008)After monsoon and ENSO signals

Annual PC1-2.0-1.5-1.0-0.50.00.51.01.52.0

1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

PC1-Coeff

NINO3-aSST

Annual PC2-0.6

-0.4

-0.2

0.0

0.2

0.4

1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

PC2-Coeff

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El Niño impact episode

Ensemble El NiEnsemble El Niñño events during 1960-1991 against climatologyo events during 1960-1991 against climatology

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La Niña impact episode

Ensemble La NiEnsemble La Niñña events during 1960-1991 against climatologya events during 1960-1991 against climatology

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ENSO episodes between rainfall and NINO3 SST

• impact starts in Aprilimpact starts in April• No impacts on the peak of rainfall season in DJFNo impacts on the peak of rainfall season in DJF• The ocean mechanism prevents the impact during the The ocean mechanism prevents the impact during the wet seasonwet season• El Nino is in-phase to the dry season, thus worsen the El Nino is in-phase to the dry season, thus worsen the casecase• La Nina has no impact in the peak of the dry season MJJ La Nina has no impact in the peak of the dry season MJJ because they are out-of-phasebecause they are out-of-phase

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Monsoonal climatology of the Maritime Continent

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Surface sea current (Wyrtki 1962)Surface sea current (Wyrtki 1962)

June December

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Role of ocean circulation in limiting the ENSO impact

Aldrian, Disertation thesis, 2003

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EL NINO / LA NINA

DIPOLE MODE POSITIFVE/ DIPOLE MODE NEGATIVE

A F R

I C A

A F R

I C A

A S I A

A S I A Ags -Sep Okt - Nov

Ags -Sep Okt - Nov

MONSOONAL WINDS

1

2

3

4

INDONESIAN SST1

2

3

4

1

2

3

4

ARAH

ANGIN MUSIM

AGS – SEP TIMURAN

OKT– NOV BARATAN

DIPOLE MODE (ºC)

SEP 09 (+) 0.38/ Netral

OKT 09 (+) 0.40/ Netral

NOV 09 (+) 0.32/ Netral

DES 09 (+) 0.22/ Netral

EL NINO (ºC)

SEP 09 1.38/ Mod

OKT 09 1.95/ Mod

NOV 09 2.07/ Kuat

DES 09 1.94/ Mod

FACTORS CONTROLLING RAINFALL IN INDONESIA

1963197219821997

El Nino and other climate characters

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Indian Ocean Dipole• The Indian Ocean Dipole (IOD) is a coupled ocean-atmosphere

phenomenon in the Indian Ocean. It is normally characterized by anomalous cooling of SST in the south eastern equatorial Indian Ocean and anomalous warming of SST in the western equatorial Indian Ocean. Associated with these changes the normal convection situated over the eastern Indian Ocean warm pool shifts to the west and brings heavy rainfall over the east Africa and severe droughts/forest fires over the Indonesian region.

El Nino and other climate characters

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Partial correlation between Indian Ocean and ENSO in the maritime continent

• Western pole - rainfall

• Eastern pole - Eastern pole - rainfallrainfall

Purwaningtyas and Aldrian 2008

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Delineation of ENSO and Indian Ocean Dipole impacts

Purwaningtyas and Aldrian 2008

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Perhatikan: Kekuatan El Nino dan Suhu perairan

1997: EN KuatSuhu perairan Indonesia ; dingin

2009; EN Lemah – Moderate Suhu Perariran Indonesia; hangat

EL NIÑO DAN DIPOLE MODE 1957 – 2007Sumber : NOAA

EL ÑINO

PERIOD

Anomali Suhu Muka Laut (0 C)

Central Pasifik (El Nino) Indonesian water Indian Ocean

(Dipole Mode)

JAS 1951 - NDJ 1951/52

+ 0.8 -0.38

MAM 1957 – MJJ 1958

+ 1.7 -0.40

JJA 1963 – DJF 1963/64 + 1.0 -0.51 + 1.5

MJJ 1965 – MAM 1966 + 1.6 -0.46 + 0.13

OND 1968 – MJJ 1969 + 1.0 -0.16 - 0.12

ASO 1969 – DJF 1969/70 + 0.8 -0.30 + 0.58

AMJ 1972 – FMA 1973 + 2.1 -0.45 (cool) + 2.30 (strg)

ASO 1976 – JFM 1977 + 0.8 -0.45 + 0.92

ASO 1977 - DJF 1977/78 + 0.8 -0.60 + 0.5

AMJ 1982 – MJJ 1983 + 2.3 -0.60 (cool) + 2.20 (strg)

JAS 1986 – JFM 1988 + 1.6 -0.05 + 1.88

AMJ 1991 – JJA 1992 + 1.8 -0.23 + 1.56

AMJ 1994 – FMA 1995 + 1.3 -0.52 + 2.73

AMJ 1997 – AMJ 1998 + 2.7 – 3.2 -0.29 (cool) + 3.22 (strg)

AMJ 2002 – FMA 2003 + 1.5 0.17 (neutral) + 0.96

MJJ 2004 – JFM 2005 + 0.9 -0.06 - 0.19

JAS 2006 - DJF 2006/07 + 1.1 -0.25 (cool) + 1.59

Agustus 200919 Sept

+0.82+0.65

0.6(warm)+0.63

-0.3 (neutral)-0.33

EN Lemah 0.5 – 1.0 0C

EN Moderate 1.0 – 2.0 0C

EN Kuat > 2.0 0C

Tahun 1972; 1982; 1997:

Pada tahun yang sama, 2 fenomena, El Nino & Dipole Mode terjadi bersama-sama curah hujan di wilayah Indonesia berkurang banyak karena didorong dari: Pantai barat Sumatera ke Afrika Timur Wilayah perairan Indonesia ke Pasifik Tengah

Level EN & DM

Update 280909

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Detecting El Nino from Indonesian seasBMKG • Data from modeling Indonesian seas from the entrance and exit

channel of the throughflow could be used as the precursor of the incoming El Nino up to 5 month in advance with high confidence level

• During El Nino the climate predictability of the region is high

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Korelasi Salinitas (Makassar,Lifamatola,Halmahera) v s SOI

-0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6

4020

2970

1995

1220

795

550

385

265

183

123

83

57

37

17

Keda

lam

n (m

)

hal

lif

mak

Korelasi Salinitas (Lombok, Ombai,Timor) v s SOI

-0.6 -0.4 -0.2 0 0.2 0.4

4020

2970

1995

1220

795

550

385

265

183

123

83

57

37

17

Keda

lam

n (m

)

tim

omb

lom

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• During La Nina (El Nino) the termocline layers will transport more (less) water mass due to ENSO modulations (Meyers, 1996). Large water mass transport is usually associated with a higher density or higher salinity water, thus whenever this layers is modulated, the water composition and density will change accordingly.

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El Nino and Indonesian climateEl Nino and Indonesian climate

During El Nino, the Indonesian water will be cooler high surface pressure in the MC, winds from Australia will be diverted to the southtern coast of MC create Ekman pumping and upwelling there good for fishery there and western coast of Sumatera. Ironically cool SST will induce drought especially in the western part of MC or the eastern dipole of the Indian Ocean. Hence, most of El Nino will be associatively related to the positive Dipole Mode. Moreover El Nino usually shutdown the MJO potency in that year.

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annual SST Aug-Dec SST

Kalimantan Sumatera Kalimantan Sumatera

1997-2004 0.94 0.83 0.95 0.93

1997-2005 0.90 0.80 0.94 0.93

1997-2006 0.77 0.75 0.84 0.90

1997-2007 0.80 0.77 0.85 0.87

Climate Feedback and forest fire

11

-2

-1

0

1

2

3

4

0

10000

20000

30000

40000

50000

60000

70000

80000

1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007

NIN

O3

SS

T a

no

mal

y

To

tal

Ho

tsp

ots

Year

a) Annual HotspotKalimantan hotspot

Sumatera hotspot

Aug SST-Anomaly

annual SST anom

-2

-1

0

1

2

3

4

0

10000

20000

30000

40000

50000

60000

70000

80000

1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007

NIN

O3

SS

T a

no

mal

y

To

tal

Ho

tsp

ots

Year

b) Jul-Dec Hotspot

Kalimantan hotspot

Sumatera hotspot

Aug-Dec SST-anom

annual SST anom

Aldrian 2007

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• According to Hendiarti et al (2005) fishery catch in seas around Java is highly seasonal. Catch decrease during El Nino in Sunda Strait, but increase in east Java.

ENSO & Fishery

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Impact of climate change and ENSO Impact of climate change and ENSO over the deep seaover the deep sea

• The global warming will increase surface temperature and its subsurface layer. Changes in temperature will largely occur in the mixing and thermocline layers. Subsequently marine acosystem will change due to comfort zone of living by ocean species.

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Impact of climate change and ENSO Impact of climate change and ENSO over the deep seaover the deep sea

• Because of global warming or strong La Nina episodes and rising of surface temperature, the ocean species will swim deeper to find the same comfort zone as before global warming happens. As a result the fish catchment must go deeper. The reverse pattern is true during El Nino event when the fish catchment increase because fish swim in shallower layers.

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Impact of global warming on the evolution of El Nino Impact of global warming on the evolution of El Nino (higher frequency) (present decade and last 3 decade)(higher frequency) (present decade and last 3 decade)

-3

-2

-1

0

1

2

3

4

1977

1977

1977

1978

1978

1978

1979

1979

1979

1980

1980

1980

1981

1981

1981

1982

1982

1982

1983

1983

1983

1984

1984

1984

1985

1985

1985

1986

1986

1986

1987

1987

1987

1988

1988

1988

-3

-2

-1

0

1

2

3

4

1997

1997

1997

1998

1998

1998

1999

1999

1999

2000

2000

2000

2001

2001

2001

2002

2002

2002

2003

2003

2003

2004

2004

2004

2005

2005

2005

2006

2006

2006

2007

2007

2007

2008

1997-2008

1977-1988

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1950-2006

Impact of global warming on the evolution of Impact of global warming on the evolution of El Nino (higher intensity)El Nino (higher intensity)

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Why El Nino intensifier due to global warmingWhy El Nino intensifier due to global warming• The Warm pool is formed due to global thermohaline circulation (the

great ocean conveyor belt) and brings surface sea water from north, south and equatorial Pacific. Those surface water is notable warm because direct solar radiation. The warm pool is the main gate of water flow from the Pacific to the Indian Ocean

• El Nino occurs during the movement of subsurface warm pool from north of Papua to central Pacific because the subsurface temperature gradient over the warm pool and central Pacific exceed the critical threshold. By classic fluid dynamics this condition will allow propagation of water masses, thus creating El Nino

• Global warming will make faster warmer warm pool

• With faster and warmer warm pool, the potency to exceed the threshold level will be faster and allowing propagation of water mass El Nino

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Competing feature of ENSO and global warming in the region

• As the earth surface temperature warmer, the evaporation rate over the tropics will increase faster and higher water cycle

• There is a tendency of wetter dry season over the maritime continent case 2009

120E-135E,15S-5S

0

2

4

6

8

10

12

14

16

18

20

25 26 27 28 29 30 31Local SST (C)

Rai

nfa

ll (

mm

/day

)

January

February

March

April

May

June

July

August

September

October

November

December

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Aldrian and Susanto, 2003, Intl J Climatol.

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Evidence of wetter climateBMKG

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Negative impacts of El Nino

• Long drought and strong potency of forest fire

• Surface water deficit and water deficit in the reservoirs, lake, dams and rivers

• Long drought means harvest failure especially in the paddy field

• Major El Nino issues: rice import, water pump, irrigation and water resources

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Positive impact of El Nino

• Fishery sector will be booming as the fish swim nearer to the surface

• Salt industry will be booming due to longer solar radiation

• Seaweed industry will be booming with cooler surface sea water

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Positive impact of El Nino• Transport sector no weather extreme• Several agriculture commodities will gain

better harvest such as onion, tabacco, teakwood, corn etc.

• Construction sectors will gain better such as building development and the cement industry

• Tourism sector will gain benefit due to longer solar radiation

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CONCLUSIONS• The maritime continent has high seasonal

predictability from tropical and maritime characters• ENSO is the second largest influences of regional

climate phenomena, whose influences are confined during the dry season due to monsoonal sea surface pattern. event and impact are different

• Indian Ocean dipole, monsoon and global warming are confounding factors affecting the impact of ENSO in the region

• Global warming has intensifier the frequency and intensity of ENSO but on the other hand warmer and wetter the maritime sea and climate

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