The large deviation principle for the stochastic 3D primitive equations with transport noise
Antonio Agresti, Esmée Theewis
TL;DR
The paper develops a rigorous small-noise large deviation principle for the three-dimensional primitive equations with transport noise, treating both Itô and Stratonovich forms. Central to the analysis is handling transport noise acting directly on the full horizontal velocity, which introduces a noncoercive setting and turbulent pressure effects; the authors overcome this with the T25L2LDP framework and a detailed barotropic/baroclinic decomposition to obtain essential a priori estimates. The skeleton equation and tilted SPDE are controlled to produce MR(0,T) bounds, enabling the LDP with a rate function given by the minimal control energy required to realize a path. This work extends the mathematical understanding of rare events in geophysical fluid dynamics models with physically meaningful transport noise and provides a pathway for analyzing climate-relevant scenarios via large deviations.
Abstract
We prove the small-noise large deviation principle for the three-dimensional primitive equations with transport noise and turbulent pressure. Transport noise is important for geophysical fluid dynamics applications, as it takes into account the effect of small scales on the large scale dynamics. The main mathematical challenge is that we allow for the transport noise to act on the full horizontal velocity, therefore leading to a non-trivial turbulent pressure, which requires an involved analysis to obtain the necessary energy bounds. Both Stratonovich and Itô noise are treated.
