Magnetic Shear and Microflaring in Active Regions Observed with TRACE
Abstract
We have previously reported results from studies that have compared the magnetic structure and heating of the transition region and corona (both in active regions and in the quiet Sun) by combining X-ray and EUV images from Yohkoh and SOHO with photospheric magnetograms from ground-based observatories. Our findings have led us to the hypothesis that most heating throughout the corona is driven from near and below the base of the corona by eruptive microflares occurring in compact low-lying "core" magnetic fields (i.e., fields rooted along and closely enveloping polarity inversion lines in the photospheric magnetic flux). We are now extending these studies to cooler plasmas, incorporating sequences of UV images from TRACE (in addition to SOHO and Yohkoh data) into a comparison with longitudinal magnetograms from MDI and Kitt Peak and vector magnetograms from MSFC. We examine statistical measures of the microflaring and its association with the degree of magnetic shear in core fields. These studies support the previous results regarding the importance of magnetic shear for core-field microflaring in active regions. This work is funded by NASA's Office of Space Science through the Sun-Earth Connection Guest Investigator Program and the Solar Physics Supporting Research and Technology Program.
- Publication:
-
American Astronomical Society Meeting Abstracts #204
- Pub Date:
- May 2004
- Bibcode:
- 2004AAS...204.3904P