[A-OS11] Ocean Mixing Frontiers

[AOS11-P04] Assessing the role of deep ocean mixing on carbon and nutrients cycles using an Earth System Model

*Michio Watanabe¹, Akitomo Yamamoto¹, Tomohiro Hajima¹, Hiroaki Tatebe¹ (1.Research Center for Environmental Modeling and Application, Japan Agency for Marine-Earth Science and Technology (JAMSTEC))

Keywords:Deep ocean mixing, Earth System Model, Carbon cycle, Nutrient cycle

Earth System Models (ESMs) that incorporate biogeochemical processes into General Circulation Models (GCMs) have been developed to project future climate. In the Earth system, the ocean redistributes heat, anthropogenic carbon dioxide absorbed from the atmosphere, and nutrients that control primary production, and the meridional circulation in the ocean plays a major role in this redistribution. The pattern and strength of this circulation is strongly controlled by microscale turbulent mixing due to tide-induced internal wave breaking in the deep ocean. However, the distribution of the intensity of deep-ocean mixing is not clear, and the effects of deep-ocean mixing on the global carbon and nutrient cycles have not been well discussed. In this study, two implementations of deep ocean mixing were used to execute an ESM under pre-industrial forcing and under increasing atmospheric CO2 concentration by 1% per year. The results will be discussed in terms of how the distribution of the intensity of deep ocean mixing affects the distribution of carbon and nutrients in the ocean.