INDAAF

International Network to study Deposition and Atmospheric composition in Africa

Description
Metadata informations

The project

INDAAF (International Network to study Deposition and Atmospheric composition in Africa) is a programme dedicated to the long-term monitoring of the atmospheric composition and of the atmospheric deposition fluxes in Africa.

The objective is to document and understand the different steps of the life-time of gaseous and particulate species from their emission, transport and chemical evolution to their deposition on the continental surfaces. Wet and dry deposition is the final stage of the biogeochemical cycles of elements having impacts on the oceanic and terrestrial ecosystems. In a context of global changes, the whole geochemical cycles of short-lived atmospheric species must be monitored. Long-term observations are required (1) by the evolution of climatic conditions in Africa and by the strong uncertainties on this evolution and (2) by the increasing anthropogenic pressure and the induced changes in the distribution of the population and in the land-use (cultivation/pasture/biomass burning/pollution from megacities).

To fulfill these objectives, the INDAAF long term monitoring network performs measurements:

of the chemical composition of the atmosphere in Africa to document the temporal and spatial evolution of trace gas and aerosol concentrations
of wet and dry atmospheric deposition fluxes using quality controlled measurements at the regional-ecosystem scale.

INDAAF is a national observatory (Service National d’Observation, SNO) of the Institut National des Sciences de l’Univers (INSU) of the Centre National de Recherche Scientifique, also supported by the Observatoire Midi-Pyrénées (OMP) and the OSU-EFLUVE, with the help of the Institut de Recherche pour le Développement (IRD). It corresponds to the union of the previously labeled IDAF-DEBITS network and the “Sahelian Dust Transect” network.

INDAAF contributes to international initiatives through:

its contribution to the long term endorsed DEBITS (Deposition of Biogeochemically Trace Species) activity part of the IGAC (International Global Atmopsheric Chemistry) programme
its contribution as an official contributing network to the WMO Global Atmospheric Watch programme (GAW) and to WMO Sand and Dust Storm Warning Advisory and Assessment System (SDS-WAS).

Observations

The INDAAF measurement network spans 10 stations across the African continent:

8 sites in West and Central Africa (Niger, Mali, Senegal, Benin, Côte d’Ivoire, Cameroon and Congo),
2 partner sites (4 in South Africa and 1 in Tunisia).

The network is representative of all major ecosystems: dry savanna, wet savanna and forest.

Measurements allows to quantify:

the monthly concentrations of several gases of atmospheric interest,
the chemical composition of aerosols at the weekly scale,
the chemical composition (mineral and organic) of precipitation at the event scale,
the deposited mass flux at the weekly scale and the wet deposition mass flux at the event scale,
the mass concentration of particulate matter (<10 µm) at the hourly scale.