AMMA

An International Research Project and Field Campaign

African Monsoon Multidisciplinary Analysis

or

Afrikanske Monsun : Multidisiplinære Analyser

or

Afrikanischer Monsun: Multidisziplinäre Analysen

or

Analisis Multidiciplinar de los Monzones Africanos

or

Analyses Multidisciplinaires de la Mousson Africaine

The interannual and interdecadal variability of the West African monsoon (WAM) is well documented and has motivated many research efforts in recent decades. The dramatic change from wet conditions in the 50s and 60s to much drier conditions in the 70s, 80s and 90s over the whole region represents one of the strongest inter-decadal signals on the planet in the 20^th century. Superimposed on this, marked interannual variations in recent decades have resulted in extremely dry years with devastating environmental and socio-economic consequences. Such variability has raised important issues related to sustainability, land degradation, and food and water security in the region. AMMA is an integrated multidisciplinary project that aims at addressing both fundamental scientific questions related to the understanding of the WAM variability and practical issues related to prediction and applications.

There is a clear need for skillful seasonal-to-interannual predictions of WAM variability and its impacts on food, water and health. Unfortunately we are currently hindered in providing this. There are still fundamental gaps in our knowledge of the coupled atmosphere-land-ocean system at least partly arising from lack of appropriate observational datasets but also because of the complex scale interactions between the atmosphere, biosphere and hydrosphere that ultimately determine the nature of the WAM. The monitoring system for the WAM and its variability is inadequate with many gaps in the standard routine network and lack of routine monitoring of some key variables; while the next generation of satellites will help, the research that will enable this still needs to be done. Dynamical models used for prediction suffer from large systematic errors in the West African and tropical Atlantic regions; current models have problems simulating fundamental characteristics of rainfall such as the diurnal, seasonal and annual cycles. Finally, there is a lack of integrative science linking the work on WAM variability and applications such as the areas of food, water and health. More effort needs to be made to integrate scientists working in these different areas.

West Africa is also an important source region for natural and anthropogenic emissions of precursors to key greenhouse forcing agents (e.g. ozone, aerosols). For example, biomass burning in savanna and forest ecosystems over Africa contributes around 20% of the global biomass burning. Long-range transport of trace gases out of West Africa also has important implications for the global oxidizing capacity of the atmosphere (which controls the level of many greenhouse gases), global climate change and the transport of key constituents (e.g. water vapour, ozone depleting substances) into the stratosphere.

• To ensure that the multidisciplinary research is effectively integrated with prediction and decision making activity

To achieve these aims a multidisciplinary approach to the study of the WAM is required involving substantial international collaboration. AMMA will link observations, data analysis and modeling on a wide range of space and time scales. The project will address the following interacting science areas: Monsoon dynamics and scale interactions, continental water cycle, aerosols, atmospheric chemistry, food, water and health.

To perform detailed investigations into the physical and chemical processes influencing the land-ocean-atmosphere system over West Africa with the aim of quantifying interactions within the system as well as impacts on local, regional and global climate. The aim is to improve the weather forecasts and the simulations of the West African climate in models used for sub-seasonal to decadal prediction, as well as those used for producing scenarios of future climate change.

To characterise the impact of West African climate variability on water resources, food security, health and development strategies and to explore the feedback of human activities on climate variability, since anthropogenic pressure plays an important role in land degradation which in turn may impact rainfall variability.

To implement a multi-scale and integrated monitoring network providing key parameters for multidisciplinary scientific investigation and prediction.

To develop blended training and education activities for African research and technical institutions.

To develop a meta-database and interoperable databases focussing upon the themes of the project.

Current observing systems do not provide all the information needed to fully understand and quantify multi-scale and multi-process interactions. The spectrum of scales to cover is very broad, ranging from local to regional (the whole of West Africa) and beyond (global). The observation strategy will thus associate operational observations (great attention will be paid to collecting and archiving historical datasets in close collaboration with African countries) with long term observations concentrated in a sub-regional window and obtained from various ongoing research projects (CATCH, IMPETUS, INTEO, GLOWA-Volta, AERONET, IDAF). In addition, intensive multi-disciplinary observations will be performed during specific periods, focusing on the understanding of key processes. The utility of bringing in additional observations for the future will be tested using modeling and assimilation systems. Recommendations for future optimal networks will result, an important demand of African services and regional agencies.

AMMA is planned to be a multi-year project and will involve 3 observing periods:

 

The Long term Observing Period (LOP) is concerned with data of two types. First, there are a number of unarchived observations that have been obtained during the past 50 years that would benefit studies on interannual-to-decadal variability of the WAM. These include rainfall and data describing land cover changes. Secondly, supplementary long term observations will be promoted to document and analyse the strong interannual variability of the WAM.

 

The Enhanced Observing Period (EOP) is designed to serve as a link between the LOP and the SOP. Its main objective is to document over a climatic transect the annual cycle of the surface conditions and of the atmospheric state variables at convective-to-synoptic spatial scales. The EOP will be of 2-3 year duration, and hopefully longer.

 

The Special Observing Period (SOP) will focus on detailed observations of specific processes at various key stages of the rainy season during 4 periods in 2006: (i) dry season, (ii) monsoon onset, (iii) peak monsoon and (iv) late monsoon

 

Satellite observations will strongly contribute to the objectives of the project by providing key variables of the surface – atmosphere system (e.g. Meteosat/MSG, ENVISAT, TRMM, AURA, AQUA-Train, TERRA, SMOS…). A challenge is to exploit this huge amount of data (20 years for Meteosat, for example) by optimising the retrievals and data analysis for monitoring as well as validation of models and assimilation. The project will provide a unique set of integrated ground observations for validation of the coming satellites. It will also provide the framework to build a reliable monitoring strategy combining satellite and in situ network, to make up for the low density of routine observations in Africa.

 

Modeling and Assimilation

 

To address the objectives of AMMA, a synergistic approach cutting across disciplines and across spatial and temporal scales is necessary. Numerical modeling and assimilation will be the main tool. Particular attention will be brought to evaluate and improve numerical prediction of weather and climate over the West African region. The enhancement of observations during the different observation periods will provide a unique opportunity to determine future operational monitoring needed to support this prediction activity.

 

 

Applications, Training and education

 

Building links between research and applications is a major objective of this project. Here models and data sets will be developed in collaboration with African institutions and International bodies so that they can test/use them as tools for decision making and to develop adaptation strategies in response to the evolving West Africa environment and climate. A particular focus of attention will be on integrating models representing various scales and applications (e.g. water resources management, crop models, health models). The collaboration between scientists working on processes and those involved in applications will be fostered through fora and training sessions. The project will also provide updated global climate change scenarios for stakeholders and hopefully better weather and seasonal forecasts.

Various on-going observing programs are already carried out in close collaboration with national and regional institutions. A colloquium held in Niamey with the participation of ACMAD and AGRHYMET in February 2002 resulted in setting up a network of over 200 African scientists from various disciplines that are involved in developing core activities related to training, blended education and applications. Summer schools, supervised PhDs, visiting scientists opportunities for African scientists and participation of researchers outside Africa in teaching in African Universities are among the various tools that will be used to build a strong links with African scientific communities. Such links already exist at national levels through specific programs but the project will provide the opportunity to rationalise and boost these efforts.

 

Contacts :AMMA WEB Site: http://medias.obs-mip.fr/amma/

 

In Africa

 

CSAM: African Coordination Committee: csam@ucad.sn Web site: http://www.ird.ne/ammanet/

• Nigeria: Leykan Oyebande: lekanoye@hotmail.com

  Professor of Hydrology; Hydrology Laboratory, Department of Geography & Planning,
  University of Lagos Akoka-Yaba, Lagos 101017, (NIGERIA)
  Phone : +234-8033086714; Fax: +234-4932669

• Ghana: miniazinede@yahoo.co.uk

  Meteorological Services Department
  P.O.Box 87 LEGON (Ghana)
  Tel: (223)21777 572 / Fax: (223) 21 777 57

• Gambia: Lamine Touray : touraylm@yahoo.co.uk

        Global Change Research Unit, Department of Water Resources
         7, Marina Parade; Banjul, (Gambia)
        Tel:(220) 224 122 / 228 216 Fax:(220) 225 009