News Release

Launching of the AMMA (1) project, an international research programme on the West African monsoon

(1)AMMA : African Monsoon Multidisciplinary Analysis

Peer-Reviewed Publication

Institut de recherche pour le développement

The climate in the tropics is regulated by the contrasts in temperature and humidity between the oceans and the continental masses. Such differences generate the monsoon events which bring the region’s rainfall. There are three major monsoon systems in the world: the Indian, the African and the South American. Of these, the African one has been subject to the strongest disturbances during the past 50 years. West Africa has, since the end of the 1960s, been experiencing its harshest, most persistent drought. The rainfall deficit has reached 50% over some parts of the Sahel. This fierce drought has had serious consequences for the people living there, bringing a general increase in poverty provoked by reduced water resources, falling crop yields or decrease in livestock numbers and a shortfall in reservoir replenishment. Is this train of events irreversible? Does it forewarn of extensive changes to the global climatic system associated in particular with greenhouse gas emissions?

Any answers to these questions will depend imperatively on a sound understanding of the various mechanisms which govern the West African monsoon, its variability and its impact on the hydrological cycle. The Niamey meeting was an opportunity to take stock of the latest scientific advances with regard to the processes behind these events and to define the main problems remaining to be tackled. The AMMA programme launched on this occasion will include a comprehensive campaign to make specific observations in different fields: atmospheric physics and chemistry, the hydrological cycle and dynamics of Sahelian and Sudanian ecosystems. AMMA will seek to determine the impact on climate of the recorded increase in temperature of the sub-tropical ocean which has occurred over the past 50 years. It will also examine the profound changes that have taken place in the vegetation of South-West Africa (the primary forest has disappeared to the benefit of crop cultivation).

An overriding objective of the AMMA programme is to strengthen over ten years or so the climate surveillance effort over a dozen or so years. This will be done by increasing the density of the measurement station network. This measurement campaign will be supplemented with several phases of intensive observations. The African research teams and operational services are taking part in planning the implementation of AMMA. They placed great emphasis on the needs in terms of training and applications: forecasting of periods of drought and of their impact on water resources and food security and of their health implications. An African committee was formed to follow the programme’s progress. It will work in close liaison with the French Coordination Committee during the project finalization phase. Several national programmes in France have already given their support. British, German and American scientists are also being involved. An international steering committee will soon be formed.

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The AMMA programme is backed in France by the CNES, CNRS, IRD and Météo-France and in Africa by regional centres such as ACMAD and AGRHYMET and by several universities). It is in keeping with the kind of action recommended by the World Programme of Research on Climate (WPCR).The CLIVAR-Africa (4) committee formed by the WPCR to study and forecast climatic variability on the continent, has also given its support.

Notes :
(2)ACMAD : African Center for Meteorological Applications to Development.
(3)AGRHYMET : AGRo-Hydro-METeorology Centre (Niamey).
(4)CLIVAR : CLImate VARiability.


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