# Topography-induced persistence of atmospheric patterns

## TL;DR

This paper models atmospheric blockings as a perturbed Rossby-Hawritz wave triad, showing that topography inhomogeneities enable persistent climate patterns by increasing the measure of their dynamical states.

## Contribution

It introduces a simplified triad model with topography perturbation to explain the persistence of atmospheric blockings, highlighting the role of inhomogeneities in flow pattern locking.

## Key findings

- Perturbed triad dynamics have a finite measure for persistent patterns.
- Static inhomogeneities are necessary for flow pattern locking.
- Model explains the onset and duration of atmospheric blockings.

## Abstract

Atmospheric blockings are persistent large-scale climate patterns with duration between days and weeks. In principle, blockings might involve a large number of modes interacting non-linearly, and a conclusive description for their onset and duration is still elusive. In this paper we introduce a simplified account for this phenomena by means of a single-triad of Rossby-Hawritz waves perturbed by one topography mode. It is shown that the dynamical features of persistent atmospheric patterns have zero measure in the phase space of an unperturbed triad, but such measure becomes finite for the perturbed dynamics. By this account we suggest that static inhomogeneities in the two-dimensional atmospheric layer are required for locking flow patterns in real space.