ECWMWF/CLIVAR Workshop on Simulation and Prediction of Intra-seasonal Variability with emphasis on the MJO, 3-6 November 2003

Climate Scale Interactions in the Indo-Pacfic Tropical Basins

Jean-Philippe Boulanger, Albert Fischer, Julie Leloup, Matthieu Lengaigne and many co-auhors…

• Role of an MJO event in the termination of the 1994-1995 Indian Dipole Event

• Role of the March 1997 WWE in ElNiño onset

• WWE activity and ENSO dynamics

• Conclusions

ECWMWF/CLIVAR Workshop on Simulation and Prediction of Intra-seasonal Variability with emphasison the MJO, 3-6 November 2003

Role of an MJO event in the termination of the 1994-1995 Indian Dipole Event

Interannual anomalies of SST and Taux duringthe 1994-1995 and 1997-1998 Dipole events

ECWMWF/CLIVAR Workshop on Simulation and Prediction of Intra-seasonal Variability with emphasison the MJO, 3-6 November 2003

Role of an MJO event in the termination of the 1994-1995 Indian Dipole Event

Strategy :

1- Study the impact of the Nov 1994 MJO in an ocean model (OPA model)

2- Study the atmospheric sensitivity to the oceanic impact of the Nov 1994 MJO (LMDZ)

ECWMWF/CLIVAR Workshop on Simulation and Prediction of Intra-seasonal Variability with emphasison the MJO, 3-6 November 2003

Role of an MJO event in the termination of the 1994-1995 Indian Dipole Event

OPA model response at the equatorto the MJO zonal wind stress signal

ECWMWF/CLIVAR Workshop on Simulation and Prediction of Intra-seasonal Variability with emphasison the MJO, 3-6 November 2003

Role of an MJO event in the termination of the 1994-1995 Indian Dipole Event

ECWMWF/CLIVAR Workshop on Simulation and Prediction of Intra-seasonal Variability with emphasison the MJO, 3-6 November 2003

Role of an MJO event in the termination of the 1994-1995 Indian Dipole Event

ECWMWF/CLIVAR Workshop on Simulation and Prediction of Intra-seasonal Variability with emphasison the MJO, 3-6 November 2003

Role of an MJO event in the termination of the 1994-1995 Indian Dipole Event

LMDZ Atmospheric responseto the simulated OPA SST patterns

ECWMWF/CLIVAR Workshop on Simulation and Prediction of Intra-seasonal Variability with emphasison the MJO, 3-6 November 2003

Role of an MJO event in the termination of the 1994-1995 Indian Dipole Event

LMDZ Atmospheric responseto the simulated OPA SST patterns

40E 60E 80E 100E- 0.06

- 0.04

- 0.02

0

0.02

0.04 N m-2

Dec

Jan

TA

UX

LMDZ Indian Ocean zonal wind mean and ensemble

REF noWWB

S O N D J F M A M J

0

0.02

0.04

- 0.04

- 0.02

1994 1995

Indian Ocean zonal wind index (70-90E 2S-2N) time evolution

ECWMWF/CLIVAR Workshop on Simulation and Prediction of Intra-seasonal Variability with emphasison the MJO, 3-6 November 2003

Role of an MJO event in the termination of the 1994-1995 Indian Dipole Event

LMDZ Atmospheric responseto the simulated OPA SST patterns

40E 60E 80E 100E

- 0.06

- 0.04

- 0.02

0.02

0

0.04 N m-2

- 0.06

- 0.04

- 0.02

0.02

0

Dec

Jan

LMDZ Indian Ocean zonal wind mean and ensemble

REF noWWB

ECWMWF/CLIVAR Workshop on Simulation and Prediction of Intra-seasonal Variability with emphasison the MJO, 3-6 November 2003

•Role of the March 1997 WWE in El Niño onset

ECWMWF/CLIVAR Workshop on Simulation and Prediction of Intra-seasonal Variability with emphasison the MJO, 3-6 November 2003

Role of the March 1997 WWE in El Niño onset

Observations

23.0

26.0

27.0

28.0

29.0

29.0

0.0

0.0

0.0

1.0

1.0

2.0

3.0

4.0

210

210

210210

210

210

210

210

210

210

0.020

0.02

0

0.040

Figure 11

140oE 180o 140oW 100oW 140oE 180o 140oW 100oW

140oE 180o 140oW 100oW 140oE 180o 140oW 100oW

(a) Observed SST

Jan 97

Jan 98

(b) Observed SST Anomaly

(c) Observed Zonal Wind Stress (d) Observed Zonal Wind stress Anom

Apr 97

Jul 97

Oct 97

Apr 98

Jan 97

Jan 98

Apr 97

Jul 97

Oct 97

Apr 98

Tim

eTi

me

-0.10 -0.06 -0.02 0.02 0.06 0.10

ECWMWF/CLIVAR Workshop on Simulation and Prediction of Intra-seasonal Variability with emphasison the MJO, 3-6 November 2003

Role of the March 1997 WWE in El Niño onset

Zonal and meridional wind stress on March, 14th, 1997

140E 160E 180 160W 140W 120W 100W 80WLongitude

20S

10S

0

10N

20N

La

titu

de

140E 160E 180 160W 140W 120W 100W 80W

Longitude

-0.25 -0.15 -0.05 0.05 0.15 0.25

Zonal Meridional

ECWMWF/CLIVAR Workshop on Simulation and Prediction of Intra-seasonal Variability with emphasison the MJO, 3-6 November 2003

Role of the March 1997 WWE in El Niño onset

Strategy :

1- Study the impact of the March 1997 WWE in an ocean model (OPA model)

2- Study the atmospheric sensitivity to the oceanic impact of the March 1997 WWE (Hadam)

3- Study the impact of the March 1997 WWE in a coupled model (HadOPA)

ECWMWF/CLIVAR Workshop on Simulation and Prediction of Intra-seasonal Variability with emphasison the MJO, 3-6 November 2003

Role of the March 1997 WWE in El Niño onset

0.0

0.00.0

0.2

0.2 0.4

0.40.6

0.6

140E 160E 180 160W 140W 120W 100W 80W

-0.2

0.0

0.0

0.2

0.2

0.2

0.4

0.6

0.6 0.

6

140E 160E 180 160W 140W 120W 100W 80W

Mar 97

Apr 97

May 97

-0.2

0.0

0.0

0.2

0.2

0.2

0.4

0.6

0.6 0.

6

33.4

33.8

34.2

34.2

34.6

34.6

34.6

35.0

35.0

140E 160E 180 160W 140W 120W 100W 80WFeb 97

Mar 97

Apr 97

May 97 -0.6

-0.6

-0.4

-0.4

-0.2 -0.2

-0.2

0.0

0.0

0.0

0.0

0.0 0.0

0.0

140E 160E 180 160W 140W 120W 100W 80W

26.0

26.5

27.0

27.5

27.5

28.028

.529

.029

.5

29.5

30.0

30.0 30

.0

30.5

140E 160E 180 160W 140W 120W 100W 80W

Mar 97

Apr 97

May 97 -0.5

0.0

0.0

0.0

0.0

0.5

0.5

1.0

1.5

2.0

140E 160E 180 160W 140W 120W 100W 80W

(a) REF (SST)

(e) REF (Surface current) (f) REF-NWE (Surface current)

(d) REF-NWE (SSS)(c) REF (SSS)

(b) REF-NWE (SST)

• Three oceanic responses in SST(1) warming along

the Kelvin wave path(2) large warming

along the EEWP(3) cooling in the

western Pacific

• Strong zonalcurrents at theEEWP associatedto anon-linear response of the thermo-halo-dynamical frontand the wind-forced zonalcurrents

ECWMWF/CLIVAR Workshop on Simulation and Prediction of Intra-seasonal Variability with emphasison the MJO, 3-6 November 2003

Role of the March 1997 WWE in El Niño onset

(a) REF OLR+SST

Mar 97

Apr 97

May 97

27.0

27.0

28.02

9.0

30.0

30.0

(b) NWE OLR+SST

27.0

27.028

.0

29.0

30.0

(c) REF OLR+TAUX

140E 180 140W 100W

Mar 97

Apr 97

May 97

180 200 220 240 260 280

-0.0

40

-0.040-0

.020

-0.0

20

0.0

00

0.0

00

0.0

20

(d) NWE OLR+TAUX

140E 180 140W 100W

180 200 220 240 260 280

-0.040

-0.0

40

-0.0

20

-0.0

20

0.0

00

Tim

e

Atmospheric responseto the simulated SST patterns

• Strong convectionnear 160°E in REF

•Large westerly winds near 160°E in REF

ECWMWF/CLIVAR Workshop on Simulation and Prediction of Intra-seasonal Variability with emphasison the MJO, 3-6 November 2003

Role of the March 1997 WWE in El Niño onset

April May

-0.02

0.00

0.02

0.04

0.06

0.08

0.10

0.12

April MayJune June

Zo

nal

Win

d S

tres

s In

ten

sity

(N

/m

2)

(a) (b)

Time

Stronger WWEactivity in REFthan in NWE: positive feedback

ECWMWF/CLIVAR Workshop on Simulation and Prediction of Intra-seasonal Variability with emphasison the MJO, 3-6 November 2003

Role of the March 1997 WWE in El Niño onset

April May June-0.06

-0.05

-0.04

-0.03

-0.02

Time

Zo

nal

Win

d S

tres

s In

ten

sity

(N

/m

2)

REF

NWE

NKW

Eastern Pacific warming leads to a reductionof the Trade Winds

ECWMWF/CLIVAR Workshop on Simulation and Prediction of Intra-seasonal Variability with emphasison the MJO, 3-6 November 2003

Role of the March 1997 WWE in El Niño onset

HadOPA coupled model experimentsHadOPA Nino3.4 SST Anomaly [year 45-75]

Jan45

Jan50

Jan55

Jan60

Jan65

Jan70

Time

-4-2024

SST

Ano

m (C

)

26.0

27.0

27.0

28.0

28.0

28.0

29.0

29.0

29.0

30.0

30.0

31.0

31.0

31.0

31.0

25.0

26.0

27.0

27.0

28.028.0

28.0

28.0

29.0

29.0

29.0

30.0

30.0

31.0

31.0

0.0

0.0

0.0

0.0

0.0

0.0

1.0

1.0

1.0

2.0

2.0

140oE 180o 140oW 100oW

Jan 62

Jan 63

Apr 62

Jul 62

Oct 62

Apr 63

140oE 180o 140oW 100oW 140oE 180o 140oW 100oW

(a) CREF mean SST (b) CWWE mean SST (c) CWWE-CREF mean SST

ECWMWF/CLIVAR Workshop on Simulation and Prediction of Intra-seasonal Variability with emphasison the MJO, 3-6 November 2003

Role of the March 1997 WWE in El Niño onset

(b) CWWE Nino34 SST Anomaly

Jan 62 Jan 63

Time

4

2

0

-2

4

2

0

-2Jan 62 Jan 63

(a) CSTA Nino34 SST Anomaly

WWE

ECWMWF/CLIVAR Workshop on Simulation and Prediction of Intra-seasonal Variability with emphasison the MJO, 3-6 November 2003

Role of the March 1997 WWE in El Niño onset

140oE

Jan 62

Apr 62

Jul 62

Oct 62

Jan 62

Apr 62

Jul 62

Oct 62

(b) Zonal Extension of the Trade Winds

(a) Location of the Eastern Edge of the Warm Pool

WWE

WWE

160oE 180o 160oW 140oW

140oE 160oE 180o 160oW 140oW

ECWMWF/CLIVAR Workshop on Simulation and Prediction of Intra-seasonal Variability with emphasison the MJO, 3-6 November 2003

Role of the March 1997 WWE in El Niño onset

Mar Jun Sep-0.5

0.0

0.5

1.0

1.5

2.0

2.5

Mar Jun Sep-0.5

0.0

0.5

1.0

1.5

2.0

2.5

Mar Jun Sep-0.5

0.0

0.5

1.0

1.5

2.0

2.5

Anomalie de SST (

°C)

CRECRE

CWECWE

CWNCWN

26262626 26262626 26262626

Mar Jun Sep-0.5

0.0

0.5

1.0

1.5

2.0

2.5

Mar Jun Sep-0.5

0.0

0.5

1.0

1.5

2.0

2.5

Mar Jun Sep-0.5

0.0

0.5

1.0

1.5

2.0

2.5

Anomalie de SST (

°C)

CRECRE

CWECWE

CEPCEP

26262626 26262626 26262626

ECWMWF/CLIVAR Workshop on Simulation and Prediction of Intra-seasonal Variability with emphasison the MJO, 3-6 November 2003

Role of the March 1997 WWE in El Niño onset

0

2

4

6

8

10

12

Neutral Moderate warming Strong warming

CRECWECWNCEPCW2

ECWMWF/CLIVAR Workshop on Simulation and Prediction of Intra-seasonal Variability with emphasison the MJO, 3-6 November 2003

Role of the March 1997 WWE in El Niño onset

Jun Sep Dec-4

-3

-2

-1

0

Jun Sep Dec-4

-3

-2

-1

0

Jun Sep Dec-4

-3

-2

-1

0

Jun Sep Dec-4

-3

-2

-1

0

Jun Sep Dec-4

-3

-2

-1

0

Jun Sep Dec-4

-3

-2

-1

0

-10

-5

0

5

10

-10

-5

0

5

10

Jun Sep DecJun Sep DecJun Sep DecJun Sep DecJun Sep DecJun Sep Dec

CRE_Cold

CWE_Cold

CRE_Cold

CWE_Cold

(a)

(b)39393939 393939 39393939

39393939 393939 39393939

ECWMWF/CLIVAR Workshop on Simulation and Prediction of Intra-seasonal Variability with emphasison the MJO, 3-6 November 2003

Role of the March 1997 WWE in El Niño onset

ECWMWF/CLIVAR Workshop on Simulation and Prediction of Intra-seasonal Variability with emphasison the MJO, 3-6 November 2003

ECWMWF/CLIVAR Workshop on Simulation and Prediction of Intra-seasonal Variability with emphasison the MJO, 3-6 November 2003

WWE activity and ENSO dynamics

ECWMWF/CLIVAR Workshop on Simulation and Prediction of Intra-seasonal Variability with emphasison the MJO, 3-6 November 2003

WWE activity and ENSO dynamics

ECWMWF/CLIVAR Workshop on Simulation and Prediction of Intra-seasonal Variability with emphasison the MJO, 3-6 November 2003

WWE activity and ENSO dynamics

ECWMWF/CLIVAR Workshop on Simulation and Prediction of Intra-seasonal Variability with emphasison the MJO, 3-6 November 2003

WWE activity and ENSO dynamics

Recent changes in ENSO characteristics

ECWMWF/CLIVAR Workshop on Simulation and Prediction of Intra-seasonal Variability with emphasison the MJO, 3-6 November 2003

Conclusions

1- Clear impact of an MJO in the terminationof the 94-95 Dipole event in the IO.

Questions:-what favors the occurrence of such an MJO in 94 and not in 97? Is it stochastic or arethere any large scale conditions favoring suchan occurrence?

ECWMWF/CLIVAR Workshop on Simulation and Prediction of Intra-seasonal Variability with emphasison the MJO, 3-6 November 2003

Conclusions

2- Strong impact of the March 1997 wind eventon El Niño

-Positive feedbacks (more WWE activity)

-Large dispersion (is it model dependent ordoes it reveal a « natural » sensitivity of the coupled system?)

-Can we define criteria associated to a risk ofextreme El Niño occurrence?

-What is the exact role of the MJO? Is it a realcontributor to ENSO or one of the mechanismsby which a strong WWE can occur? In such a case, as much efforts should be put inmodelling the other mechanims (e.g. coldsurges, cyclones, etc…) as in modelling MJO.

ECWMWF/CLIVAR Workshop on Simulation and Prediction of Intra-seasonal Variability with emphasison the MJO, 3-6 November 2003

Conclusions

3- WWE and ENSO:Is the change in dynamics observed with the1982-1983 Event related to a differentimpact/sensitivity of IntraSeasonal Activity inthe Pacific?