The primitive equations with rough transport noise: Global well-posedness and regularity
Antonio Agresti
TL;DR
The paper develops global well-posedness and instantaneous regularization results for the primitive equations under rough transport noise with Hölder regularity γ>1/2. By working in an $L^q$ setting with $q>2$ and identifying critical anisotropic Besov spaces $B^{2/q}_{(q,2),p}$ that reflect vertical anisotropy, the authors achieve stochastic maximal regularity-based well-posedness even for Kraichnan-type noise with α>1 and for Kolmogorov-spectrum-type forcing. The framework extends to non-isothermal models and Stratonovich formulations, providing a robust treatment of turbulence-like transport in geophysical flows. These results advance the mathematical understanding of stochastic PDEs in anisotropic, non-Hilbert settings and have potential implications for modeling turbulent oceanic and atmospheric dynamics.
Abstract
In this paper we establish global well-posedness and instantaneous regularization results for the primitive equations with transport noise of Hölder regularity $ γ>\frac{1}{2}$. It is known that if $γ<1$, then the noise is too rough for a strong formulation of primitive equations in an $L^2$-based setting. To handle rough noise, we crucially use $L^q$-techniques with $q> 2$. Interestingly, we identify a family of critical anisotropic Besov spaces for primitive equations, which is new even in the deterministic case. The behavior of these spaces reflects the intrinsic anisotropy of the primitive equations and plays an essential role in establishing global well-posedness and regularization. Our results cover Kraichnan's type noise with correlation greater than one, and as a by-product, a 2D noise reproducing the Kolmogorov spectrum of turbulence. Moreover, the instantaneous regularization is new also in the widely studied case of $H^1$-data and $γ>1 $.
