The monsoon system is characterised by a seasonal meridional oscillation in winds and rainfall, which gives rise to dry winters and wet summers in the tropics. This system is driven by the seasonal temperature difference that develops between the ocean and the continent, and between the two hemispheres. It thus plays a vital role in the global distribution of heat and moisture. Palaeoclimatic studies show that the dynamics of regional monsoon systems have varied over time, particularly during the Quaternary, depending on the Earth’s orbital parameters and solar radiation forcing. It appears that complex processes and interactions involving, for example, the extent of ice caps, changes in atmospheric pCO₂, and ocean dynamics, have also contributed to the variability in monsoon dynamics over time. However, on the continents, past variations in precipitation and wind regimes determine the vulnerability of rocks to erosion by influencing river flow, vegetation types and soil types. They thus affect the chemical weathering of source areas, the mobilisation of sedimentary material on the continents, and its transport by rivers and/or wind to ocean basins. In the oceans, they generate significant changes in surface water dynamics, particularly in the depth of the thermocline/nutricline, which have a considerable impact on primary producers (coccolithophores in particular). It is within this context that the multi-methodological study (sedimentological, mineralogical, geochemical and micropalaeontological) of sedimentary records collected in the contexts of the African, Indian and Asian monsoons enables us to address, from various angles, the issue of monsoon system variability, across different spatio-temporal scales.

Objectives of the Research Theme: Our research focuses on studying the variability in the dynamics of the monsoon system across the world’s tropical regions during the Late Quaternary. Our aim is to contribute to a better understanding of both the forcings associated with the monsoon system and to investigate the associated palaeo-environmental changes at low latitudes, as well as the existing climatic teleconnections with mid- and high-latitudes.

List of permanent and non-permanent staff:

C. Skonieczny, C. Colin, S. Alphonse-Duchamp, S. Sépulcre, M. Leblanc, A. Plautre