Multi-Scale Oceanographic Numerical Modelling in Support of Regional Marine Science

Particles, including larvae, microplastics and contaminants, are suspended in the water and drift at the mercy of these currents. The ocean is a tremendously complex environment, however; currents arise from a myriad of forcing mechanisms such as tides, wind, sea surface elevation and internal density differences that each evolve at different timescales. As these flows interact with topography, the currents become even more complex at progressively smaller scales. Added complexity arises through natural global climate patterns such as the El Nino Southern Oscillation (ENSO) and anthropogenic change. Such complexity cannot be adequately measured with in-situ instrumentation across this range of scales, demanding a different approach to understanding how the ecosystem responds to changes in the physical environment.

To bridge this barrier, we will combine oceanographic numerical models that simulate ocean conditions at progressively smaller scale. Beginning with the basin scale, we will simulate over multiple years the effects of processes that act over the whole Indian Ocean including the monsoon and Indian Ocean Dipole. Then, we will progressively ‘zoom in’ to smaller scales, from a regional Chagos Archipelagos-scale simulation to one that resolves the complexity arising from interaction of currents with individual atolls and seamounts. By combining these simulations with satellite observations, we will provide the comprehensive understanding of oceanographic conditions that underpin the conservation efforts underway throughout the Chagos Archipelago and the wider Indian Ocean.