E-Print Archive

There are 2659 abstracts currently viewable.
There is a problem with some abstracts that became corrupted following database issues. These will be restored as soon as possible.


Search:

Advanced Search
Options
Main Page Add New E-Print Submitter
Information
Feedback
News Help/FAQ About Preferences
Manage Key Phrase
Notification
Lagrangian coherent structures in photospheric flows and their implications for coronal magnetic structure View all abstracts by submitter

Anthony Yeates   Submitted: 2012-06-21 07:01

Aims. We show how the build-up of magnetic gradients in the Sun's corona may be inferred directly from photospheric velocity data. This enables computation of magnetic connectivity measures such as the squashing factor without recourse to magnetic field extrapolation. Methods.Assuming an ideal evolution in the corona, and an initially uniform magnetic field, the subsequent field line mapping is computed by integrating trajectories of the (time-dependent) horizontal photospheric velocity field. The method is applied to a 12 hour high-resolution sequence of photospheric flows derived from Hinode/SOT magnetograms. Results. We find the generation of a network of quasi-separatrix layers in the magnetic field, which correspond to Lagrangian coherent structures in the photospheric velocity. The visual pattern of these structures arises primarily from the diverging part of the photospheric flow, hiding the effect of the rotational flow component: this is demonstrated by a simple analytical model of photospheric convection. We separate the diverging and rotational components from the observed flow and show qualitative agreement with purely diverging and rotational models respectively. Increasing the flow speeds in the model suggests that our observational results are likely to give a lower bound for the rate at which magnetic gradients are built up by real photospheric flows. Finally, we construct a hypothetical magnetic field with the inferred topology, that can be used for future investigations of reconnection and energy release.

Authors: A.R. Yeates, G. Hornig, and B.T. Welsch
Projects: Hinode/SOT

Publication Status: A&A 539, A1, 2012
Last Modified: 2012-06-21 09:17
Go to main E-Print page  Chirality of High Latitude Filaments over Solar Cycle 23  Study of flare energy release using events with numerous type III-like bursts in microwaves  Edit Entry  Download Preprint  Submitter's Homepage 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
Solar-cycle related variation of solar differential rotation
Internal-cycle variation of solar differential rotation
The standard flare model in three dimensions III. Slip-running reconnection properties
Global axis shape of magnetic clouds deduced from the distribution of their local axis orientation
Fine-scale Structures of Flux Ropes Tracked by Erupting Material
The influence of numerical resolution on coronal density in hydrodynamic models of impulsive heating
Spectral diagnostics with the SDO EVE flare lines
A revised radiometric calibration for the Hinode/EIS instrument
Disturbances in the U.S. electric grid associated with geomagnetic activity
Origin of Macrospicule and Jet in Polar Corona by A Small-scale Kinked Flux-Tube
Spatially Resolved Microwave Observations of Multiple Periodicities in a Flaring Loop
Changes in quasi-periodic variations of solar photospheric fields: precursor to the deep solar minimum in the cycle 23?
Pathways of large-scale magnetic couplings between coronal events
Superflares on Solar-Type Stars Observed with Kepler II. Photometric Variability of Superflare-Generating Stars : A Signature of Stellar Rotation and Starspots
A Challenging Solar Eruptive Event of 18 November 2003 and the Causes of the 20 November Geomagnetic Superstorm. I. Unusual History of an Eruptive Filament
Hi-C & AIA observations of transverse MHD waves in active regions
Geometric properties of acoustic waves generated by a point source in the solar-like interior: effects of acoustic cutoff frequency
Study of Failed CME Core Associated with Asymmetric Filament Eruption
Simulation of the Observed Coronal Kink Instability and Its Implications for the SDO/AIA
Investigating Two Successive Flux Rope Eruptions In A Solar Active Region

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