Helicity transport through the photosphere
Abstract
Solar eruptions are driven by energy and helicity transported through the photosphere and into the Corona. However, the mechanism by which helicity is transferred from the solar dynamo to coronal structures is pooly understood. We recast the Berger and Field (1984) helicity transport equation in manifestly gauge invariant form and examine the individual terms leading to the transport of helicity through the emergence of closed field, and twisting and tangling of potential fields. These theoretical results are applied to erupting active regions observed by SDO/HMI. The plasma velocity fields in the photosphere, necessary for computing energy and helicity fluxes are determined using an upgraded version of DAVE4VM that incorporates the spherical geometry of the solar images. We find that the bulk of the helicity into the corona is injected by twisting motions, and we discuss the implications of our results for understanding coronal activity.
- Publication:
-
AGU Spring Meeting Abstracts
- Pub Date:
- May 2013
- Bibcode:
- 2013AGUSMSH53C..04S
- Keywords:
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- 7524 SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY / Magnetic fields;
- 7513 SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY / Coronal mass ejections;
- 7519 SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY / Flares;
- 7531 SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY / Prominence eruptions