Modeling the Impact of Paleogeography on Cretaceous Ocean Deoxygenation

International audience Oceanic Anoxic Events (OAEs) were geologically short-lived events of widespread ocean deoxygenation and marine organic carbon burial and occurred mostly during the Cretaceous period. The development of OAEs is largely attributed to the impact of massive volcanism on climate an...

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Bibliographic Details
Main Authors: Donnadieu, Yannick, Ladant, Jean-Baptiste
Other Authors: Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
Format: Conference Object
Language:English
Published: HAL CCSD 2022
Subjects:
[SDU]Sciences of the Universe [physics]
North Atlantic
Online Access:https://insu.hal.science/insu-03938068
https://doi.org/10.5194/egusphere-egu22-11663
Description
Summary:International audience Oceanic Anoxic Events (OAEs) were geologically short-lived events of widespread ocean deoxygenation and marine organic carbon burial and occurred mostly during the Cretaceous period. The development of OAEs is largely attributed to the impact of massive volcanism on climate and marine biogeochemistry; however, the lack of similar events during other carbon-cycle perturbations suggests additional mechanisms. We use the IPSL-CM5A2 Earth System Model to assess the role of changing paleogeography in priming the Cretaceous Ocean for large-scale decrease in intermediate and deep oxygen concentrations. We focus on three time-slices that present differences in potential gateway (e.g. the Central American Seaway) depth and basin configuration (e.g. the North Atlantic): the Aptian age (~120 Ma), the Cenomanian-Turonian boundary (~94 Ma) and the Maastrichtian age (~70 Ma). This set of simulations illustrates the impact of paleogeography on global circulation and its consequences for intermediate and deep water oxygenation. We also show results for two different atmospheric CO2 concentrations (2x and 4x pre-industrial) to study the additional influence of differing climatic states on oxygenation and primary productivity, and their importance relative to ocean dynamics.

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