Centre Européen
de Recherche et d'Enseignement
des Géosciences de l'Environnement

Paleo-monsoons, Paleo-ENSO, paleo-circulation

The dynamics of the monsoon, the ENSO (El Niño Southern Oscillation) and the oceanic paleo-circulations form a structuring axis of the research of the Climate team.

 

In the marine environment, studies initiated later in the inter-tropical zone are continued, especially those concerning the tropical Pacific. The team's efforts are focused on the reconstruction of a proxy of the paleo-ENSO activity on the scale of the last climate cycle, as well as on a synthesis of hydrological (SST and salinity) and ecological conditions in the western Pacific "Warm Pool" on the Holocene scale, associated with an effort of data-model comparison, all developed in the framework of the PACMEDY project (2016-2018, PI local L. Beaufort).

 

In the Indo-Pacific area, sedimentary records (Mozambique Channel, Bay of Bengal and West Pacific, Arabian Sea) are analyzed to reconstruct the dynamics of climate, the Indian monsoon and the evolution of calcareous phytoplankton. The focus is on the terminal Miocene period of high atmospheric CO2 concentration (projet ANR JC iMonsoon). The Plio-Pleistocene climate dynamics of the Indo-Pacific Warm Pool is studied from IODP Exp 363 boreholes and IMAGES cores collected by CEREGE. In particular, reconstructions of ocean circulation changes using paleoclimatic parameter proxies (SST, SSS, d18O, d13C), analyzed for several years at CEREGE, but also using innovative proxies (Nd isotopic composition on foraminifera, dD on organic compounds, 14C reservoir ages) are pursued (projet RICH-LEFE, PI K. Tachikawa, projet EQUIPEX ASTER-CEREGE; ANR ISOBIOCLIM . Efforts on paleoceanographic reconstructions in the Mediterranean area will also be continued (ANR HAMOC; MISTRALS-Paleomex).

The response of the Asian monsoon to several forcings (orbital parameters, vegetation change and Tibetan plateau uplift) is studied in the framework of the ERC MAGIC project with the IPSL Earth System model. The response of ocean circulation to paleogeographic changes during the Cretaceous and its impact on the distribution of marine productivity zones and on the distribution of carbonate producers is simulated in two projects funded by Total (PI: Y. Donnadieu) in collaboration with the RRH team (J. Borgomano).