Sensibilité d'un modèle océan-atmosphère (LMDZ-NEMOMED8) à un flux d'eau douce: Cas du dernier épisode de sapropèle en Mer Méditerranée

Sapropel events occur periodically in the Mediterranean Sea, produce a strong stratification of the water column, slow down and break the intermediate and deep convection and lead to a decrease in oxygen in deep water. This decrease is recorded in marine sediment core. Sapropels are a wide-study case and links between insolation changes, African monsoon, and anoxia event are well documented. Moreover, many observations provided data over Mediterranean soil to better understand the anoxia process in particular for the last sapropel, SI, that occurred 10,000 years ago and lasted 3000 years. Climate modelling has long been used to reproduce ancient climate and study the future changes, but the higher resolution needed to have a robust thermohaline circulation has only been implemented recently in Mediterranean oceanic models. In this study, hosing experiments using a coupled oceanic and atmospheric model have been carried out by modifying the Nile discharge river, according to the dominant hypothesis for sapropel SI. With an estimations of the Nile discharge for the early Holocene, we are able to shut down the deep convection in East basin and Adriatic Sea.