Adapting to life: Ocean ecosystem modelling using an unstructured and adaptive mesh ocean model
Seminar Room 1, Newton Institute
Primary production in the world ocean is significantly controlled by meso- and sub-mesocale process. Thus existing general circulation models applied at the basin and global scale are limited by two opposing requirements: to have high enough spatial resolution to resolve fully the processes involved (down to order 1km) and the need to realistically simulate the basin scale. No model can currently satisfy both of these constraints. Adaptive unstructured mesh techniques offer a fundamental advantage over standard fixed structured mesh models by automatically generating very high resolution at locations only where and when it is required. Mesh adaptivity automatically resolves fine-scale physical or biological features as they develop, optimising computational cost by reducing resolution where it is not required.
Here, we describe Fluidity-ICOM, a non-hydrostatic, finite-element, unstructured mesh ocean model, into which we have embedded a six-component ecosystem model, that has been validated at a number of ocean locations. We show the different meshes that arise from using different metrics to create the adaptive mesh and from the underlying physical and biological processes that occur at each station. We then apply the model to a three-dimensional restratification problem and examine the effect of mesh resolution on simulated biological productivity on both fixed and adaptive meshes.