Delta-singular vortex dynamics on a rotating sphere and stability of coupled atmospheric centers of action

TL;DR

This paper investigates the dynamics and stability of coupled atmospheric vortex centers on a rotating sphere, deriving conditions for stationary modes and their instability, with relevance to observed atmospheric phenomena.

Contribution

It introduces a new stationary vortex mode on a rotating sphere and provides a stability criterion considering polar vortex effects.

Findings

Stationary vortex mode exists only when the cyclonic vortex is at a higher latitude than the anticyclonic one.

A stability criterion for the vortex mode is derived, indicating conditions for exponential instability.

The theoretical results align with observed atmospheric data and reanalysis of oceanic atmospheric centers.

Abstract

Existence of a stationary mode for a Hamiltonian dynamic system of two point vortexes with different signs on different latitudes of a uniform rotating sphere complying with observed data is stated. It is shown that such mode realization is possible only in the case when the more intensive cyclonic vortex has greater latitude than that of the anticyclonic vortex. A criterion of exponential instability of the stationary vortex mode taken into account impact of the polar vortexes is obtained. Compliance of the theory to observed data and reanalysis for coupled quasi-stationary systems of cyclonic and anticyclonic atmosphere action centers above oceans in the Northern Hemisphere is considered.