Effect of weak rotation on large-scale circulation cessations in turbulent convection

TL;DR

This study examines how weak rotation influences the large-scale circulation in turbulent convection, revealing that rotation significantly affects cessation frequency and amplitude fluctuations, aligning well with experimental data.

Contribution

It provides a theoretical analysis of rotation effects on LSC cessations and fluctuation statistics in turbulent convection, extending previous models to include rotation.

Findings

Rotation increases cessation frequency at certain Rayleigh numbers.

Distribution tails of reorientation remain unchanged with rotation.

Rotation significantly alters LSC amplitude and cessation statistics.

Abstract

We investigate the effect of weak rotation on the large-scale circulation (LSC) of turbulent Rayleigh-B\'{e}nard convection, using the theory for cessations in a low-dimensional stochastic model of the flow previously studied. We determine the cessation frequency of the LSC as a function of rotation, and calculate the statistics of the amplitude and azimuthal velocity fluctuations of the LSC as a function of the rotation rate for different Rayleigh numbers. Furthermore, we show that the tails of the reorientation probability distribution function remain unchanged for rotating systems, while the distribution of the LSC amplitude and correspondingly the cessation frequency are strongly affected by rotation. Our results are in close agreement with experimental observations.