Comparing two different types of stochastic parametrisation in geophysical flow

TL;DR

This paper compares two stochastic parametrisation methods in geophysical flow models, analyzing their effects on solution sensitivity and structure preservation in the thermal quasigeostrophic equations.

Contribution

It introduces and compares two types of structure-preserving stochastic perturbations, one in bathymetry and another in velocity, within geophysical flow models.

Findings

Bathymetry stochasticity affects solution ensemble spread.

Velocity stochasticity preserves structure but impacts solution sensitivity.

Both methods maintain key conservation laws.

Abstract

This paper investigates the effects of stochastic variations in bathymetry on the solutions of the thermal quasigeostrophic (TQG) equations. These stochastic perturbations generate a variety of different types of ensemble spread in the solution behaviour whilst also preserving the deterministic Lie Poisson structure and Casimir conservation laws. We numerically compare the solution sensitivity, to another type of structure-preserving stochastic perturbation where instead of bathymetry, the velocity is stochastically perturbed.