E-Print Archive

There are 4102 abstracts currently viewable.


Search:

Advanced Search
Options
Main Page Add New E-Print Submitter
Information
Feedback
News Help/FAQ About Preferences
Manage Key Phrase
Notification
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 

Key
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
Three-dimensional Density Structure of a Solar Coronal Streamer Observed by SOHO/LASCO and STEREO/COR2 in Quadrature
Modelling Mg II During Solar Flares, I: Partial Frequency Redistribution, Opacity, and Coronal Irradiation
The Birth of a Jet-driven Twin CME and Its Deflection from Remote Magnetic Fields
On the Origin of Solar Torsional Oscillations and Extended Solar Cycle
What Sets the Magnetic Field Strength and Cycle Period in Solar-type Stars?
Stereoscopic Observations of an Erupting Mini-filament Driven Two-Sided-Loop Jet and the Applications for Diagnosing Filament Magnetic field
Dynamic Processes of the Moreton Wave on 2014 March 29
Shock Heating Energy of Umbral Flashes Measured with Integral Field Unit Spectroscopy
Stealth Coronal Mass Ejections from Active Regions
Coronal Loop Scaling Laws for Various Forms of Parallel Heat Conduction
Structure of the transition region and the low corona from TRACE and SDO observations near the limb
Quantifying the relationship between Moreton-Ramsey waves and "EIT waves" using observations of 4 homologous wave events
Formation of quasi-periodic slow magnetoacoustic wave trains by the heating/cooling misbalance
Fundamental Transverse Vibrations of the Active Region Solar Corona
Damping of slow magnetoacoustic oscillations by the misbalance between heating and cooling processes in the solar corona
Magnetic helicity and eruptivity in active region 12673
Impulsive coronal heating from large-scale magnetic rearrangements: from IRIS to SDO/AIA
Probing the effect of cadence on the estimates of photospheric energy and helicity injections in eruptive active region NOAA AR 11158
The birth of a coronal mass ejection
Oscillations of the baseline of solar magnetic field and solar irradiance on a millennial timescale

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