E-Print Archive

There are 4002 abstracts currently viewable.


Advanced Search
Main Page Add New E-Print Submitter
News Help/FAQ About Preferences
Manage Key Phrase
The Magnetic Helicity Budget of Solar Active Regions and Coronal Mass Ejections View all abstracts by submitter

Alexander Nindos   Submitted: 2003-05-26 07:59

We compute the magnetic helicity injected by transient photospheric horizontal flows in 6 solar active regions associated with halo coronal mass ejections (CMEs) that produced major geomagnetic storms and magnetic clouds (MCs) at 1 AU. The velocities are computed using the local correlation tracking (LCT) method. Our computations cover time intervals of 110-150 hours and in 4 active regions the accumulated helicities due to transient flows are factors of 8-12 larger than the accumulated helicities due to differential rotation. As has been first pointed out by Demoulin & Berger (2003), we suggest that the helicity computed with the LCT method yields not only the helicity injected from shearing motions but also the helicity coming from flux emergence. We compare the computed helicities injected into the corona with the helicities carried away by the CMEs using the MC helicity computations as proxies to the CME helicities. If we assume that the length of the MC flux tubes is ell=2 AU then the total helicities injected into the corona are a factor of 2.9-4 lower than the total CME helicities. If we use the values of ell determined by the condition for the initiation of the kink instability in the coronal flux rope or ell=0.5 AU then the total CME helicities and the total helicities injected into the corona are broadly consistent. Our study, at least partially, clears up some of the discrepancies in the helicity budget of active regions because the discrepancies appearing in our paper are much smaller than the ones reported in previous studies. However they point out the uncertainties in the MC/CME helicity calculations and also the limitations of the LCT method which underestimates the computed helicities.

Authors: A. Nindos, J. Zhang, H. Zhang
Projects: None

Publication Status: ApJ, in press
Last Modified: 2003-05-26 07:59
Go to main E-Print page  TRACE and YOHKOH Observations of a White Light Flare  Does solar flare activity lag behind sunspot activity?  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 of a Tiny Brightening in a Huge Geo-effective Solar Eruption Leading to the St Patrick's Day Storm
A basal contribution from p-modes to the Alfvénic wave flux in the corona
Multiwavelength Study of Equatorial Coronal-Hole Jets
Non-thermal hydrogen Lyman line and continuum emission in solar flares generated by electron beams
Determining normal mode features from numerical simulations using CEOF analysis: I. Test case using transverse oscillations of a magnetic slab
Modelling the Effect of Mass-Draining on Prominence Eruptions
Transverse waves in coronal flux tubes with thick boundaries: The effect of longitudinal flows
Electron distribution and energy release in magnetic reconnection outflow regions during the pre-impulsive phase of a solar flare
Benchmarking CME arrival time and impact: Progress on metadata, metrics, and events
First Unambiguous Imaging of Large-Scale Quasi-Periodic Extreme-Ultraviolet Wave or Shock
Coronal Imaging with the Solar UltraViolet Imager
Investigation of pre-flare dynamics using the weighted horizontal magnetic gradient method: From small to major flare classes
Seismological determination of the Alfvén speed and plasma-beta in solar photospheric bright points
Dynamo Wave Patterns Inside the Sun Revealed by Torsional Oscillations
Evidence of Twisting and Mixed-polarity Solar Photospheric Magnetic Field in Large Penumbral Jets: IRIS and Hinode Observations
Dissipation scale lengths of density turbulence in the inner solar wind
On the Possibility of Generating Harmonics of the Electron Plasma Frequency in the Solar Atmosphere due to Explosive Instability in a System of Interpenetrating Electron and Ion Flows
Determination of the total accelerated electron rate and power using solar flare hard X-ray spectra
Transition from axi- to nonaxisymmetric dynamo modes in spherical convection models of solar-like stars
Can high-mode magnetohydrodynamic waves propagating in a spinning macrospicule be unstable due to the Kelvin-Helmholtz instability?

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

© 2003 Solar Physics Group - Montana State University