AMMA phase 2 and THORPEX-Africa

AMMA phase 2 and THORPEX-Africa

Jean Philippe Lafore

CNRM-GAME, Météo-France and CNRS, Toulouse, France

With thanksto the AMMA-International Scientific Steering Committee

and to the numerous participants to AMMA

WWRP-THORPEX African Regional Committee meeting8-10 May 2012, Geneva, Switzerland

évaluation AERES 15-17 janvier 2008

2

-10%

-20%

20%

10%

0

Wet period

Dry Period

The largest regional deficit of rainfall observed during the last centuryThe largest regional deficit of rainfall observed during the last century


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Uncertainties Uncertainties aabout the futurebout the future


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Climate Variability Impacts

WaterAgricultureHealthDemographicsSecurity


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Outline

1. AMMA project Some major outcomes of AMMA-1 Main objectives of AMMA-2

2. Current tasks in the THORPEX area Forecaster’s handbook NWP ISV

3. Conclusion

30th Conference on Hurricanes and Tropical Meteorology (15-20 April 2012)

Dry spells

Flooding: Ghana 07


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National Operational

ServicesRegional Centers

AMMA: An international program on West African monsoon variability and society-environment-climate interactions

Researchers

Societal needs

Forecasts/EWS

Observations

Scientific questions

Knowledge Models

Aim 1 To improve our understanding of the West African Monsoon

variability

Main contribution of AMMA phase 1 (2002-10)

THORPEX-Africa

Greater emphasisin AMMA-2

Aim 3 To ensure that the AMMA research is

integrated with prediction & decision

making activities (Forecast/EWS)

Aim 2To provide the underpinning

science to relate WAM variability to related societal

issues To define & implement relevant monitoring & prediction strategies


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Research field experiments / Database & library

Observation networks; Modelling; Satellite Products tailored & validated

Training/Education: PhD (160 incl 80 Africans!!) Masters, Summer Schools, Workshops

Communication (external & internal)

AMMA: Established an International Community

Coordination : Multidisciplinary, Different communitiesInternational : ~600 people from 30 countries

Africa : ~250 pers ; Research and Application (Forecast/EWS) communities

AMMA coordinated with international programmes and bodies


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Ewiem Nimdie Summer School - July 2008


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Multidisciplinary Observations 1400 questionnaires of a socio-economic studyNatural resources data

Géré à l’OMP

AMMA Bibliography

mirrored in Africa at AGHRYMET (Niamey)

Other projects: FENNEC, ALMIP2, ESCAPE,…

http://database.amma-international.orghttp://amma.agrhymet.ne


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Radiosoundings: A Major Achievement of AMMA

The AMMA radiosonde budget was about 2.5 M€The AMMA radiosonde budget was about 2.5 M€ Operational agencies in the region launched the great majority of these sondes. Around Operational agencies in the region launched the great majority of these sondes. Around 50% of these were the routine operational commitment, which has continued by and 50% of these were the routine operational commitment, which has continued by and large.large. A significant fraction of the data were not communicated to the GTS.A significant fraction of the data were not communicated to the GTS.

Funding issue to maintain a basic operational networkFunding issue to maintain a basic operational networkProject submitted to DG/Dev of EU (via SECAO) no newsProject submitted to DG/Dev of EU (via SECAO) no news


Impact on TCWV Average over the period 1 Aug-14 Sep’06

Assimilation of AMSU-B over land

TCWV (EXP-CTL)

More humidity in EXP

TCWV diurnal cycle at TOMB

Karbou et al, 2009a, b

• Positive impact of the assimilation of AMSU over land• Large impact over Tropics in Monsoon regions• especially over Africa and in region with a poor data coverage• Improvement of the diurnal cycle


Assimilation of AMSU-B over land

T (EXP-CTL)

Vz (EXP-CTL)

Karbou et al. 2009a, b

AEJ increase

évaluation AERES 15-17 janvier 2008EUMETSAT (28-30 June 2011)WMO RAI Dissemination Expert Group 2nd Meeting

Assimilation of AMSUB over land

24h

Karbou et al. 2009a, b

Smaller errors in EXP

48h72h

• Positive impact of the assimilation of AMSU over land

• Large impact over all Tropics on the wind field in the upper troposphere

Forecast errors versus ECMWF analyses (forecast–analysis) 200hPa Z, 1-31 Aug’06

Difference between EXP and CTR


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AMMA, ACMAD, Météo-France, OMM, Services Météo Nationaux Africains

New forecasting methods in Africa Knowledge transfer Researchers Forecasters

Outcome Example: Forecast for civil security (Aviation, Floods, etc)


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AMMA Forecast method: WASA/F

West African Synthetic Analysis/Forecast

List of the 10 key features to put

1. ITD 2. Heat-Low3. SubTrop Jet4. Trough from midlatitude5. TEJ6. AEJ7. Troughs and cyclonic centres associated to African

Easterly Waves (AEW) 8. Midlevel dry intrusions9. Monsoon layer

10. Convective activity:a. Suppressed convection b. Convection: isolated, MCS and Squall Lines

9 Provided by models

Other features

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WASA

19 July 2006 AT 0600Z

WASF from D-1 WASF from D-2


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AMMA Phase 2 (2010-2020)

Updated International Science Plan completed December 2010www.amma-international.org/IMG/pdf/ISP2_v2.pdf

Research Themes:(i) Interactions, Society, Climate(ii) Weather, Seasonal and Climate Predictability and

Prediction(iii) Monsoon System

Priorities• Capacity building• Aims 2 and 3 will receive greater emphasis in phase 2


THORPEX-Africa


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Forecasters’ Handbook for West Africa

The forecasters’ handbook aims to:– Document existing best-practice for the region– Import and test new ideas from other parts of the world;– Exploit new scientific results from AMMA (e.g. use of land-surface remote sensing

for daily to intraseasonal forecasting.

The project has formal WMO / WWRP / THORPEX-Africa support; ACMAD is leading the management

– Well structured (chapters, editotial committee…) – We hope to publish this as a commercial book (this option is preferred by the

African participants) – Target timescale for completion: 2013.

Lack of funding to support this project and more especially African contribution (short stays of African forecasters to elaborate materials)

– it’s not a text book (forecasting methods, Illustrations)– Case studies for training (AOC website already provides many examples)– Some support from NERC (only meetings)



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Evaluation of TIGGE and ECMWF forecast products over West and Central Africa

Collaboration: – LOCEAN (Janicot), ANACIM (N’Diaye), Cameroon (Kamsu)

TIGGE multi-models ensemble runs : forecasts at 15-day range– 2008-2012– Evaluation for all seasons of the main 15-day modes and MJO-mode over West

and Central Africa

ECMWF ensemble simulations at 45 and 60-day ranges– Hindcast over 1989-2008; ensemble runs : forecast twice a month (every fifteen

days, the first one at 45-day range, the second one at 60-day range)– Evaluation for all seasons of the main 15-day modes and MJO-mode over West

and Central Africa– Courtesy F. Vitard (ECMWF)



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Real-time monitoring and forecast of intraseasonal variability ISV

Major progresses during the last decade in documenting and understanding the African ISV

3 main timescales:

25-90 days:

– link to the MJO (e.g. Matthews 2004, Janicot et al. 2009)

10-25 days:

– Quasi-Biweekly Zonal Dipole (QBZD, Mounier et al. 2008)

– Sahelian mode (Janicot et al. 2010),

– Variability of the Saharan Heat Low and link with midlatitudes (Chauvin et al. 2010, Roehrig et al. 2011)

3-10 days:

– African Easterly Waves (e.g. Kiladis et al. 2006),

– Synoptic variability of precipitable water (Couvreux et al. 2010, Poan et al. 2012),

– Kelvin waves (Mounier et al. 2007) Objectives:

– Confront the climatology to the real world;

– Investigate the forecast skill of the monsoon ISV, based on our current knowledge

Approach:

– Address these 2 points through a real-time exercice

10-25 days: Sahelian mode

OLR


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Project « ISV-monitoring »

Collaboration between France & Senegal (ANACIM, LPAO-SF): involving forecasters

– Started in 2011– Monsoon season JJAS

A real-time website, simple but easily and rapidly evolving, according to the encountered needs and ideas

Use of websites providing complementary information (broader context)

– e.g. MJO: Wheeler’s website + NCEP

Regular briefing & reports (~2/week) between Toulouse and Dakar.

http://isv.sedoo.fr


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fdb

HLE – 7 June “Canonical” HLE

Km s-1

“Canonical” HLWHLW – 16 June

Km s-1

Shading: θ850 anomaliesBlack contours: raw θ850

Vectors: wind anomalies at 850 hPaGreen contours: raw sea level pressure

High similarities with canonical events: they make sense in the “real world”

Overview of 2011 ISV: 10-25-day scale


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3 HLE events: 5-9 June, 18-24 July, 1-4 Sep

4 HLW: 12-18 June, 25 June-1 July, 10-14 Aug,7-10 Sep

The season begins with a HLE event, favorable to the monsoon onset (Roehrig et al. 2011)

Heat Low intraseasonal index

HLE1 HLE2 HLE3

HLW1 HLW2 HLW3 HLW4

HLW5

HLE4

Overview of 2011 ISV: 10-25-day-scale


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PW anomalies [12N-20N]

kg m-2

Synoptic Variability of Precipitable Water (PW)

Overview of 2011 ISV: 1-10-day scale

High correlation (0.57) between precipitation and PW over Senegal, especially after the monsoon onset (0.63).

High potential of the PW variable

PW anomalies Rain gauge precipitation

PW a

nom

alie

s (k

g m

-2)

Precip (mm

day-1)

June July August Sept

Precipitable Water index and Rainfall: over Senegal

Same characteristics as the canonical mode: frequency, propagation Differences between the eastern and the western Sahel structures (as in Poan et al 2012)


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Conclusion for the « ISV-monitoring »

Conclusions: – 10-25 days

• Monitoring of heat low variability provides some large-scale information on the monsoon system. The relationship with the onset (Roehrig et al. 2011) seems to work this year

• The monitoring of the QBZD and Sahelian modes is less obvious (not shown).

– Synoptic scales:• PW has a large potential: high predictability, strong relationship with

precipitation.

Future:– New exercise in 2012: with new diagnostics and with higher involvement of

Senegalese forecasters– Quantitative evaluation of:

• Diagnostics (e.g., filtering effects)• Skills of ECMWF forecasts for different scales(PW, Heat Low…)



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• AMMA will continue:- To mobilize, reinforce & coordinate the African & international communities working on the West African monsoon and its societal impacts.

- To combine Observations, Forecasts, Capacity building, Knowledge transfer to better anticipate and mitigate the human (and natural) impacts of weather and climate variability

• Challenges to consolidate AMMA-Africa - To strengthen * visibility and support regionally & in each country * collaboration between research & application communities * integration of African PhDs in research & application

(NHMS/EWS) centers

- To maintain & improve observation network to forecast & monitor weather and climate variabilities and its impacts

Final Thoughts

AMMA phase 2 and THORPEX-Africa

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