On a system of equations arising in meteorology: Well-posedness and data assimilation
Eduard Feireisl, Piotr Gwiazda, Agnieszka Świerczewska-Gwiazda
TL;DR
The paper analyzes data assimilation for a rotating Oberbeck–Boussinesq model that arises as a singular limit ($\varepsilon\to 0$) of the 3D compressible Navier–Stokes–Fourier system with rotation and a temperature gradient. It proves global well-posedness and dissipativity for the reduced rOB system, develops a continuous nudging data-assimilation framework using an interpolant, and establishes exponential convergence to a reference trajectory; it then connects these results to the full 3D model via a relative entropy approach. By combining the reduced model analysis with relative entropy, the authors justify assimilating data at the lower-dimensional level while controlling assimilation error in the full 3D setting, offering potential computational savings for weather prediction. The framework highlights when and how to apply nudging in a physically relevant, rotation-influenced convection context, providing a robust bridge between simplified and full atmospheric models with rigorous guarantees. These results support efficient, accurate data assimilation workflows in meteorology that exploit natural dimensional reduction without sacrificing fidelity to the underlying 3D dynamics.
Abstract
Data assimilation plays a crucial role in modern weather prediction, providing a systematic way to incorporate observational data into complex dynamical models. The paper addresses continuous data assimilation for a model arising as a singular limit of the three-dimensional compressible Navier-Stokes-Fourier system with rotation driven by temperature gradient. The limit system preserves the essential physical mechanisms of the original model, while exhibiting a reduced, effectively two-and-a-half-dimensional structure. This simplified framework allows for a rigorous analytical study of the data assimilation process while maintaining a direct physical connection to the full compressible model. We establish well posedness of global-in-time solutions and a compact trajectory attractor, followed by the stability and convergence results for the nudging scheme applied to the limiting system. Finally, we demonstrate how these results can be combined with a relative entropy argument to extend the assimilation framework to the full three-dimensional compressible setting, thereby establishing a rigorous connection between the reduced and physically complete models.
