Simulations of Stratified Aqueous Plume Dispersion
Ocean alkalinity enhancement (OAE) experiments have the potential to sequester carbon from the air into the ocean and counteract ocean acidification. These experiments consist of releasing a dense alkaline solution or particulates by the coast or into the open ocean to promote biogeochemical activity. However, the transport and mixing of dense alkaline plumes at the submesoscale are not well understood. Submesoscale flows are highly nonlinear, causing strong energy transfers between horizontal and vertical motion that enhances mixing in the ocean. Additionally, while the benefits of OAE are quantified on long-term time scales (years), short-term time scales (hours-days) must be studied to avoid negative impacts on the local environment of the release site. In this study, we simulate the short-term dispersion of non-reacting, transient, dense, aqueous plumes using the open-source code Oceananigans.Ìý
Our model resolves the non-hydrostatic wave-average Boussinesq equations without bathymetry to understand the mixing and transport of plumes in open ocean environments. We then analyze the influence of the mixed layer depth, stratification intensity, and density of the aqueous solution to understand their respective spatiotemporal impacts on mixing and transport at the submesoscale. The influences from all types of submesoscale turbulence, biogeochemistry, including finite-rate carbonate chemistry, and bathymetry are not present in these simulations and will be addressed in future work.