E-Print Archive

There are 4507 abstracts currently viewable.


Advanced Search
Main Page Add New E-Print Submitter
News Help/FAQ About Preferences
Manage Key Phrase
Testing magnetic helicity conservation in a solar-like active event View all abstracts by submitter

Etienne Pariat   Submitted: 2015-06-30 04:01

Magnetic helicity has the remarkable property of being a conserved quantity of ideal magnetohydrodynamics (MHD). Therefore, it could be used as an effective tracer of the magnetic field evolution of magnetised plasmas. Theoretical estimations indicate that magnetic helicity is also essentially conserved with non-ideal MHD processes, e.g. magnetic reconnection. This conjecture has however been barely tested, either experimentally or numerically. Thanks to recent advances in magnetic helicity estimation methods, it is now possible to test numerically its dissipation level in general three-dimensional datasets. We first revisit the general formulation of the temporal variation of relative magnetic helicity on a fully bounded volume when no hypothesis on the gauge are made. We introduce a method to precisely estimate its dissipation independently of the type of non-ideal MHD processes occurring. In a solar-like eruptive event simulation, using different gauges, we compare its estimation in a finite volume with its time-integrated flux through the boundaries, hence testing the conservation and dissipation of helicity. We provide an upper bound of the real dissipation of magnetic helicity: It is quasi-null during the quasi-ideal MHD phase. Even when magnetic reconnection is acting the relative dissipation of magnetic helicity is also very small (<2.2%), in particular compared to the relative dissipation of magnetic energy (>30 times larger). We finally illustrate how the helicity-flux terms involving velocity components are gauge dependent, hence limiting their physical meaning. Our study paves the way for more extended and diverse tests of the magnetic helicity conservation properties. Our study confirms the central role that helicity can play in the study of MHD plasmas. For instance, the conservation of helicity can be used to track the evolution of solar magnetic fields, from its formation in the solar interior until their detection as magnetic cloud in the interplanetary space.

Authors: E. Pariat; G. Valori; P. Démoulin & K. Dalmasse
Projects: None

Publication Status: Accepted in Astronomy and Astrophysics
Last Modified: 2015-06-30 10:45
Go to main E-Print page  Using the transit of Venus to probe the upper planetary atmosphere  An automated classification approach to ranking photospheric proxies of magnetic energy build-up  Edit Entry  Download Preprint  Delete Entry 

Go to main E-Print pageGo to main E-Print page.
Previous AbstractPrevious Abstract.
Next AbstractNext Abstract.
Download PreprintDownload Preprint.
Submitter's HomepageSubmitters Homepage.
Edit EntryEdit Entry.
View All Abstracts By SubmitterView all abstracts by submitter.
Delete AbstractDelete abstract.

Latest Entries
The role and contribution of magnetic fields, characterized via their magnetic flux, to the statistical structuring of the solar atmosphere
Do periods of decayless kink oscillations of solar coronal loops depend on noise?
Automatic detection technique for solar filament oscillations in GONG data
Probing the Density Fine Structuring of the Solar Corona with Comet Lovejoy
Confined plasma transition from the solar atmosphere to the interplanetary medium
Extracting the Heliographic Coordinates of Coronal Rays using Images from WISPR/Parker Solar Probe
Two-spacecraft detection of short-period decayless kink oscillations of solar coronal loops
Genesis and Coronal-jet-generating Eruption of a Solar Minifilament Captured by IRIS Slit-raster Spectra
First detection of transverse vertical oscillation during the expansion of coronal loops
A New Position Calibration Method for MUSER Images
Sigmoid Formation Through Slippage of A Single J-shaped Coronal Loop
MHD Simulation of Homologous Eruptions from Solar Active Region 10930 Caused by Sunspot Rotation
Dropouts of Fully Stripped Ions in the Solar Wind: A Diagnostic for Wave Heating versus Reconnection
Plasma heating and nanoflare caused by slow-mode wave in a coronal loop
The Lyman-α Emission in a C1.4 Solar Flare Observed by the Extreme Ultraviolet Imager aboard Solar Orbiter
Imaging and Spectroscopic Observations of the Dynamic Processes in Limb Solar Flares
Evolution of the critical torus instability height and CME likelihood in solar active regions
A Magnetogram-matching Method for Energizing Magnetic Flux Ropes Toward Eruption
A 2D Model for Coronal Bright Points: Association with Spicules, UV bursts, Surges and EUV Coronal Jets
The relativistic solar particle event on 28 October 2021: Evidence of particle acceleration within and escape from the solar corona

Related Pages
MSU Solar Physics.
Max Millennium Science Mail Archive.
Max Millennium Message of the Day Mail Archive.
Max Millennium Flare Catalog

Archive Maintainer
Alisdair Davey

© 2000-2020 Solar Physics Group - Montana State University