Simulations of stratified aqueous plumes dispersion at the submesoscale

Ocean alkalinity enhancement (OAE) experiments have the potential to sequester carbon from the air into the ocean. These experiments consist of releasing a dense alkaline solution or particulates by the coast or into the open ocean to promote biological activity. However, the transport, mixing, and biogeochemical activity 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. 

 

In this study, we simulate the dispersion of non-reacting, transient, negatively buoyant, aqueous plumes at the submesoscale using the open-source code Oceananigans. Our model resolves the non-hydrostatic wave-average Boussinesq equations with and without bathymetry to understand the mixing and transport of plumes in both coastal and open ocean environments. We then analyze the influence of bathymetry, stratification intensity, Langmuir turbulence, and submesoscale eddies to understand their respective impacts on mixing and transport. The influences of biogeochemistry, including finite-rate carbonate chemistry, are not present in these simulations and will be discussed in future work.