Non-Hydrostatic Effects in the Interaction between Flow and Orography

TL;DR

This paper investigates how non-hydrostatic effects, stratification, and Froude number influence flow-blocking and streamline patterns over orography, highlighting the complexity beyond simple predictive parameters.

Contribution

It provides a detailed analysis of the roles of vertical advection, stratification, and Froude number in flow-blocking and streamline formation, emphasizing the limitations of traditional predictive parameters.

Findings

Vertical advection significantly affects flow-blocking.

Streamline curvature and stratification influence pressure perturbations.

Flow-blocking cannot be predicted solely by stratification or Froude number.

Abstract

The interaction between flows and orography is a fundamental aspect of theoretical fluid dynamics for its direct applications (e.g., in dynamical meteorology); a comprehensive description is nowadays still lacking in some aspects. In this work, in particular, the authors would like to face the problem of flow-blocking and of the streamlines pattern formation, examining the role of stratification (i.e., Brunt-Vaisala frequency) and Froude number on these problems. In particular this work wants to investigate the role of vertical advection on flow-blocking and on streamlines geometry. The importance of streamlines curvature and stratification for the formation of pressure perturbation, then their role in flow-blocking will be shown. Moreover it will be shown how flow-blocking cannot be easly predict using only a stratification parameter or the Froude number.