Incompressible and fast rotation limits for 3D compressible rotating Euler system with general initial data
Mikihiro Fujii, Yang Li, Pengcheng Mu
TL;DR
This work analyzes the simultaneous low Mach and fast rotation limits for the 3D compressible rotating Euler equations in the whole space with ill-prepared data. By introducing an intermediate 2D system and employing Strichartz-type dispersion for fast waves, it proves local well-posedness with uniform estimates and separates dynamics into slow and fast components. The slow part is shown to converge to a 2D quasi-geostrophic type system, while the fast part decays at a rate $\delta^{1/q}$, thereby justifying the 2D QG limit in this setting. A by-product result establishes a rigorous link from the 2D inviscid rotating shallow water equations to the 2D QG equations. The findings address open questions (e.g., Ngo and Scrobogna) and provide a framework for singular limits in geophysical fluid models with mixed-dimensional data, combining intermediate systems, spectral decompositions, and dispersive estimates.
Abstract
This paper is concerned with the low Mach and Rossby number limits of $3$D compressible rotating Euler equations with ill-prepared initial data in the whole space. More precisely, the initial data is the sum of a $3$D part and a $2$D part. With the help of a suitable intermediate system, we perform this singular limit rigorously with the target system being a $2$D QG-type. This particularly gives an affirmative answer to the question raised by Ngo and Scrobogna [\emph{Discrete Contin. Dyn. Syst.}, 38 (2018), pp. 749-789]. As a by-product, our proof gives a rigorous justification from the $2$D inviscid rotating shallow water equations to the $2$D QG equations in whole space.
