English
 
User Manual Privacy Policy Disclaimer Contact us
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
  Internally driven inertial waves in geodynamo simulations

Ranjan, A., Davidson, P. A., Christensen, U. R., & Wicht, J. (2018). Internally driven inertial waves in geodynamo simulations. Geophysical journal international, 213(2), 1281-1295. doi:10.1093/gji/ggy046.

Item is

Basic

show hide
Item Permalink: http://hdl.handle.net/21.11116/0000-0003-81B6-D Version Permalink: http://hdl.handle.net/21.11116/0000-0003-81B7-C
Genre: Journal Article

Files

show Files

Locators

show

Creators

show
hide
 Creators:
Ranjan, A., Author
Davidson, P. A., Author
Christensen, Ulrich R.1, Author              
Wicht, Johannes1, Author              
Affiliations:
1Department Planets and Comets, Max Planck Institute for Solar System Research, Max Planck Society, ou_1832288              

Content

show
hide
Free keywords: Dynamo: theories and simulations, Rapid time variations, Time-series analysis
 Abstract: Inertial waves are oscillations in a rotating fluid, such as the Earth’s outer core, which result from the restoring action of the Coriolis force. In an earlier work, it was argued by Davidson that inertial waves launched near the equatorial regions could be important for the α2 dynamo mechanism, as they can maintain a helicity distribution which is negative (positive) in the north (south). Here, we identify such internally driven inertial waves, triggered by buoyant anomalies in the equatorial regions in a strongly forced geodynamo simulation. Using the time derivative of vertical velocity, ∂uz/∂t, as a diagnostic for traveling wave fronts, we find that the horizontal movement in the buoyancy field near the equator is well correlated with a corresponding movement of the fluid far from the equator. Moreover, the azimuthally averaged spectrum of ∂uz/∂t lies in the inertial wave frequency range. We also test the dispersion properties of the waves by computing the spectral energy as a function of frequency, ϖ, and the dispersion angle, θ. Our results suggest that the columnar flow in the rotation-dominated core, which is an important ingredient for the maintenance of a dipolar magnetic field, is maintained despite the chaotic evolution of the buoyancy field on a fast timescale by internally driven inertial waves.

Details

show
hide
Language(s): eng - English
 Dates: 2018
 Publication Status: Published in print
 Pages: -
 Publishing info: -
 Table of Contents: -
 Rev. Method: Peer
 Identifiers: DOI: 10.1093/gji/ggy046
 Degree: -

Event

show

Legal Case

show

Project information

show

Source 1

show
hide
Title: Geophysical journal international
Source Genre: Journal
 Creator(s):
Affiliations:
Publ. Info: Oxford [u.a.] : Blackwell
Pages: - Volume / Issue: 213 (2) Sequence Number: - Start / End Page: 1281 - 1295 Identifier: ISSN: 0956-540X
CoNE: https://pure.mpg.de/cone/journals/resource/0956-540X