Rolls of the internal gravity waves in the Earth's atmosphere

O Onishchenko,O Pokhotelov,A Smolyakov,V Fedun,W Horton,T Kaladze

doi:10.5194/angeo-32-181-2014

Abstract

Abstract. The effect of the wind shear on the roll structures of nonlinear internal gravity waves (IGWs) in the Earth's atmosphere with the finite vertical temperature gradients is investigated. A closed system of equations is derived for the nonlinear dynamics of the IGWs in the presence of temperature gradients and sheared wind. The solution in the form of rolls has been obtained. The new condition for the existence of such structures was found by taking into account the roll spatial scale, the horizontal speed and wind shear parameters. We have shown that the roll structures can exist in a dynamically unstable atmosphere.

Highlights

The energy transfer from the Earth’s lithosphere to the atmosphere and ionosphere is a fundamental problem of geophysics and applied research
The nonlinear dynamics of high-frequency Internal gravity waves (IGWs) will be studied in the local Cartesian coordinate system (x, y, z), where the z axis coincides with the vertical direction
Equations (9) and (10) constitute the full set of reduced equations that describe the nonlinear dynamics of IGWs with spatial scales smaller than 2Lρ in the atmosphere with finite wind shear

Summary

Introduction

The energy transfer from the Earth’s lithosphere to the atmosphere and ionosphere is a fundamental problem of geophysics and applied research. IGWs, propagating upward from the Earth’s surface to the upper atmosphere and ionosphere, are able to carry a large amount of energy and momentum These waves are crucial in atmosphere convection, generation of atmospheric turbulence and may affect global circulation. The amplitude of IGWs propagating upward throughout the various regions of the Earth’s atmosphere and ionosphere grow with height and become unstable due to parametric instability as a result of resonant wave–wave interaction. Such parametric generation of largescale zonal structures by high-frequency finite-amplitude IGWs has been investigated recently by Horton et al (2008) and Onishchenko and Pokhotelov (2012).

Reduced hydrodynamic equations

Convective cells

Findings

Conclusions