1. The AMMA programme Results & new challenges from a WCRP perspective
4/27/2019
The AMMA programme
Results & new challenges from a WCRP perspective
Jean Luc Redelsperger, LPO & CNRM, France
E. Afiesima, A. Diedhiou, S. Janicot, T. Lebel, D.J. Parker, C. Thorncroft (AMMA Executive Committee) 1

2. The largest regional deficit of rainfall observed during the last century
Sahel rainfall index
Wet period
20%
10%
-10%
-20%
Dry Period

3. UNCERTAINTIES ABOUT THE FUTURE

4. Precip Jul-Aug-Sept: (2070-99) minus (1960-99)
Last IPCC report, SRES A1b: Uncertainties on rain changes for future years
Precip Jul-Aug-Sept: ( ) minus ( )
Decrease over Sahel
Increase over Sahel

5. African Monsoon Multidisciplinary Analyses
Afrikanske Monsun: Multidisiplinære Analyser
Afrikaanse Moesson Multidisciplinaire Analyse
Analisi Multidisciplinare per il Monsone Africano
Afrikanischer Monsun: Multidisziplinäre Analysen
Analisis Multidiciplinar de los Monzones Africanos
Analyses Multidisciplinaires de la Mousson Africaine `

6. A coordinated international program on West African monsoon, its variability and society-environnement-ressources-climat Interactions
Aim 1
To improve our understanding of the WAM & its influence on environment regionally & globally
Aim 2
To provide the underpinning science
-to relate WAM variability to related societal issues
-to define & implement relevant monitoring & prediction strategies
Aim 3
To ensure that the AMMA research is integrated with prediction & decision making activities (EWS)
Phase 1:
Coordination : Multidisciplinary Research , Different communities
International : ~600 people from 30 countries
Africa : ~250 pers ; Research and Application (Forecast/EWS) communities
Field experiments
Long term multidisciplinary observation networks
Modelling; Satellite Products tailored & validated
Unique database with mirror in Africa (Obs, Models, Sat, Library)
Training/Education: PhD (160 incl 80 Africans) Masters, Summer Schools, Workshops
Communication (external & internal)
AMMA coordinated with international programmes and bodies

7. Research field experiments
A coordinated international program on West African monsoon, its variability and society-environnement-ressources-climat Interactions
Aim 1
To improve our understanding of the WAM & its influence on environment regionally & globally
Aim 2
To provide the underpinning science
-to relate WAM variability to related societal issues
-to define & implement relevant monitoring & prediction strategies
Aim 3
To ensure that the AMMA research is integrated with prediction (weather to climate) & decision making activities (EWS)
Research field experiments
SOP 2006:
- First international experiment in Africa at regional scale
- A unique data set documenting simultaneously the sea-air-continent system over a full seasonal cycle and over an eco- climatic transect

8. A coordinated international program on West African monsoon, its variability and society-environnement-ressources-climat Interactions
Aim 1
To improve our understanding of the WAM & its influence on environment regionally & globally
Aim 2
To provide the underpinning science
-to relate WAM variability to related societal issues
-to define & implement relevant monitoring & prediction strategies
Aim 3
To ensure that the AMMA research is integrated with prediction (weather to climate) & decision making activities (EWS)
Field experiments
SOP 2006:
-First international experiment in Africa at regional scale
- A unique data set documenting simultaneously the sea-air-continent system over a full seasonal cycle and over an eco- climatic transect
EOP : 3 years of unprecedented monitoring of water, energy, aerosol cycles over land, ocean and atmosphere at the regional and mesoscale, coordinated with socio-economic observation strategies
LOP 2002 – 2009: A long term monitoring program of key continental and oceanic regions

9. Multidisciplinary observatories on agriculture, vegetation, livestock and climate
Agriculture surveys:
9 sites (from 450mm to 900mm per year), 2 to 10 villages per site, 3 crop types & many varieties
Rangeland surveys: transects (from 100mm to 1000mm per year), > 50 sites on various soils, vegetation types and pastoral pressure status 10

10. Restoring the West African radiosonde network necessary to make forecasts & to monitor climate
July 2004
August 2006
Greatest density of atmospheric soundings ever launched with 21 active stations
200 radiosonde operators and technicians working on the network + students and researchers from Africa, the Americas and Europe

11. AMMA Radiosoundings: A Major Achievement of AMMA

12. Example: Weather & climate forecast to advice the agricultural sector
Red : Date of first rainfall over Sahel
Blue: Date of cold water formation in Gulf of Guinea
Equatorial region of gradients of surface flux (Ocean towards Atmosphere)
To forecast the beginning of the rainy season (monsoon onset)
To better advice for first seeding in Sahel
=> See poster of Thorncroft Session xx

13. ALMIP illustration Africa maps

14. Annual cycle of sensible heat flux (Mean 2005-2007)
60 X 60 km2 : 3 AMMA-CATCH stations in Mali
Aggregated (green aera : spread) ; ALMIP LSM average +/- stabdard deviation(purple)
The three-year average ( ) observed Qh for the three local sites are indicated by the non-filled symbols, and the shaded green area corresponds to the spread of the spatially aggregated fluxes (representing the 60x60 km2 meoscale domain). The solid purple curves enclose a region bounded by +/- one standard deviation about the ALMIP LSM average Qh averaged over Note that Exp. 3 results are used here since they extend to The observed flux data for this figure were taken from Timouk et al. (2009).
ISBA
It is hard to say in detail...but when we do the local scale runs for ALMIP2, we hope to get a better idea of "why"...but we can say already: Most of the models used (in some way) ECOCLIMAP, so the albedo and emissivity was nearly the same among the models...along with the same imposed forcing, so Rnet is probably NOT a big contributor to model discrepancy. This then likely points to an over-estimated Evap after the rainy season. (It could be a vegetation-roughness or z0h/z0m issue since the z0 changes after the rainy season) It could be related to other aspects too of course (soil moisture uptake, etc...) but again, I'll look more closely at the local scale..
Figure from Boone, A. et al , BAMS 2009 ; Observations from Timouk et al J Hydrol 2009

15. Global
Global SST
Teleconnections
Remote effects of MJO 10 4 km
Regional
Scales Interactions
Monsoon Systems
Major River Basins 10 3 km
Mesoscale
Mesoscale
Convective
Systems
Intraseasonal scale is a central scale fro the understanding of Monsoon variability and its impacts 10 2 km
Catchments
Vegetation
Soil
Deep Conv
Cells
Pools
Vegetation
Soil
Local
Shallow
Cells 10 1 km
Hour
Day
Season
Year
Diurnal
Cycle
Seasonal
Cycle
Interannual
Variability

16. Atmospheric boundary layer feedback to soil moisture anomalies
Wind & surface temperature spectrally coherent down to λ~20km
PBL & surface temperature spectrally coherent down to λ ~ 20km
Surface-induced temperature gradients induce wind convergence

17. Surface rain & Energy budget: Observations & AMIP Simulations
Sahel 15°N
Cumulative rainfall
Surface net radiation
OBSERVATIONS
(Black curve)
Major problems in models, even before the monsoon onset & the rain
Multiples possible reasons : Surface representation but also aerosols & clouds
+ 7 modèles
simulations avec
SST prescrite
Traoré, Guichard, Hourdin
PRECIPITATIONS & BILAN ENERGETIQUE A LA SURFACE

18. First picture of the West Africa atmospheric composition Airborne measurements
Average CO concentrations through out troposphere (>50hPa) based on 1-min data from the Bae-146, DLR Falcon, French Falcon
20th July-21 AUgust

19. First tests to improve NWP products & EWS
AMMA Phase 1 ( )
Aim 1
To improve our understanding of the WAM & its influence on environment regionally & globally
Aim 2
To provide the underpinning science
-to relate WAM variability to related societal issues
-to define & implement relevant monitoring & prediction strategies
Aim 3
To ensure that the AMMA research is integrated with prediction & decision making activities (EWS)
First tests to improve NWP products & EWS
Process knowledge
Multi-scale & multi-disciplinary with emphasis on geophysics part
Building the scientific ground basis & a community to work on societal-climate issues

20. Scale Integration (up/down) & Pluri-disciplinary
AMMA Phase 2 ( )
Aim 1
To improve our understanding of the WAM & its influence on environment regionally & globally
Aim 2
To provide the underpinning science
-to relate WAM variability to related societal issues
-to define & implement relevant monitoring & prediction strategies
Aim 3
To ensure that the AMMA research is integrated with prediction & decision making activities (EWS)
International Science Plan 2 ( ) (
Research Themes: (i) Interactions, Society, Climate
(ii) Weather, Seasonal and Climate Predictability and Prediction
(iii) Monsoon System
Observations, Capacity Building & training, Coordination and scientific diffusion
To move from understanding of system processes toward the one of process system (WAM)
To pull-through of knowledge to improve prediction of weather & climate variability and associated societal impacts (New/Improved Climat & Weather Models; EWS ; tailored products)
Scale Integration (up/down) & Pluri-disciplinary 
 Interactions Societies-Environment-Climate
Relevant monitoring for Application & Research in regard societal-climate issues

21. AMMA has been very successful in its first phase:
Improved understanding of the WAM in particular
Establishment of observational network
Built an international community in partnership with Africans
Implemented important and crucial capacity building activities
AMMA Phase 2 has great challenges:
Pull-through of knowledge to improve prediction of weather and climate variability and associated societal impacts
Maintain monitoring observation network
Maintain strong coordination providing
benefits from the go-to community for issues related to climate variability & climate change in the West African region
linkages between science and applications for the benefit of society
Partnership between numerous isolated projects sharing AMMA aims and benefiting AMMA (community, knowledge, database, …)
Promote and strengthen AMMA-African leadership
Lessons learned – to benefit the whole of Africa.