BAOBAB

BAOBAB (Base Afrique de l'Ouest Beyond AMMA Base)

Description
Metadata informations

BAOBAB/AMMA is an international programme that studies the West African monsoon, its variability and its links with socio-economic aspects. Its objectives are to improve our understanding of the monsoon and its impact on the physical, chemical and biological environment on a regional and global scale, to provide the basic scientific knowledge to establish the links between climate variability and problems of health, water resources and food security, and to define appropriate monitoring strategies.

The Project

AMMA (African Monsoon Multidisciplinary Analysis) is an international programme that studies the West African monsoon, its variability and its links with socio-economic aspects.

The objectives of the AMMA project :

To improve our understanding of the West African monsoon and its impact on the physical, chemical and biological environment on a regional and global scale.
To provide the basic scientific knowledge that will enable us to establish the links between climate variability and problems of health, water resources and food security and to define appropriate monitoring strategies.
To ensure that this multidisciplinary research within AMMA benefits forecasting and decision-making activities.

Observations

The long-term observation period (LOP) consists of two types of observations:

historical observations to study interannual-to-decadal variability
additional long-term observations (2002-2010) to document and analyse the inter-annual variability of the AOM.
LOP observations are conducted from 3 main meso-sites, with enhanced observations of rainfall, hydrology, surface and subsurface conditions:

the Ouémé catchment in Sudan (frequent rainfall in summer and lush vegetation)
the region of Niamey in the Sahel (more intense but less rainfall in summer, semi-arid)
the Mali site in the north of the Sahel (semi-arid and drier than the Niamey site). These contrasts are linked to the strong southern gradients in surface conditions that characterise the region and the associated monsoon dynamics that influence the magnitude of rainfall from the MOA towards the poles.

In order to assess interannual and seasonal variability, six EGEE cruises are scheduled in the Gulf of Guinea, with two cruises per year planned between 2005 and 2007.

The Enhanced Observation Period (EOP) provides the link between the LOP and the SOP. Its objective is to provide data on the variability of key components of the regional climate system between 2005 and 2007. The year 2006 will see the strengthening of the observation system in certain areas in order to better understand the dynamics of the monsoon and the formation of rainfall.

3 main types of observations :

Atmospheric: additional radiosondes in West Africa, new surface current measurements, ground-based and remote sensing observations (radars, profilers).
Surface: hydrological and vegetation measurements in Niger and Benin in particular, in order to characterise the structure of storm systems and the distribution of rainfall, probing of the structure of the atmosphere, measurements of radiation, cloud properties and surface meteorological parameters.
Oceanic: In addition to this deployment on the continent, oceanic measurements of atmospheric flux are made from a research vessel in the Gulf of Guinea during two annual cruises, one in June and one in September of each EOP year.

In order to assess interannual and seasonal variability, six EGEE cruises are scheduled in the Gulf of Guinea, with two cruises per year planned between 2005 and 2007.

the onset of the monsoon (15 May-30 June)
the peak of the monsoon (1 July-14 August)
the withdrawal of the monsoon (15 August-15 Sept)

The measurements provided during SOPs, combined with those established during LOPs and EOPs, provide the international community with an invaluable set of observations to study the interactions and multi-scale processes that determine the nature of the West African Monsoon and its variability.