Modelling of ocean circulation in the Newfoundland Basin

Abstract

The average temperature of the Earth's surface has increased significantly since preindustrial levels and continues to rise. This global warming is caused by the increased level of greenhouse gases in the atmosphere, particularly carbon dioxide (CO₂). To reduce the rate of temperature increase, it is necessary to decrease the amount of CO₂ in the atmosphere. One way to achieve this is by allowing oceans to absorb more CO₂ through a process known as ocean alkalinity enhancement (OAE), which occurs when alkaline particles are added to the ocean surface. The observational tracking of particle trajectories through the ocean presents significant challenges; therefore, ocean models are primary tools for predicting particle trajectories. This research focuses on ocean modelling around the Newfoundland Basin. The Regional Ocean Modelling System (ROMS) has been implemented for this region. ROMS is a hydrostatic, free-surface ocean model which uses a terrain-following vertical coordinate. The continuous model equations of ROMS, along with their numerical implementations, are described. The model initialization, as well as the definition of surface forcing and boundary conditions, are presented. The method of particle tracking in ROMS is described. Preliminary results from model simulations of ocean characteristics, including ocean temperature, salinity, and sea surface height, for July 2020 are outlined. Particle trajectories after a month of circulation within the Newfoundland Basin are shown. Future work, including extended model duration and different particle distribution methods, is then discussed in the context of applications to OAE.