NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Contagious Coronal Heating from Recurring Emergence of Magnetic FluxFor each of six old bipolar active regions, we present and interpret Yohkoh/SXT and SOHO/MDI observations of the development, over several days, of enhanced coronal heating in and around the old bipole in response to new magnetic flux emerge= within the old bipole. The observations show: 1. In each active region, new flux emerges in the equatorward side of the old bipole, around a lone remaining leading sunspot and/or on the equatorward end of the neutral line of the old bipole. 2. The emerging field is marked by intense internal coronal heating, and enhanced coronal heating occurs in extended loops stemming from the emergence site. 3. In five of the six cases, a "rooster tail" of coronal loops in the poleward extent of the old bipole also brightens in response to the flux emergence. 4. There are episodes of enhanced coronal heating in surrounding magnetic fields that are contiguous with the old bipole but are not directly connected to the emerging field. From these observations, we suggest that the accommodation of localized newly emerged flux within an old active region entails far reaching adjustments in the 3D magnetic field throughout the active region and in surrounding fields in which the active region is embedded, and that these adjustments produce the extensive enhanced coronal heating. We also note that the reason for the recurrence of flux emergence in old active regions may be that active region flux tends to emerge in giant-cell convection downflows. If so, the poleward "rooster tail" is a coronal flag of a long-lasting downflow in the convection zone. This work was funded by NASA's Office of Space Science through the Solar Physics Supporting Research and Technology Program and the Sun-Earth Connection Guest Investigator Program.
Document ID
20020022350
Acquisition Source
Marshall Space Flight Center
Document Type
Conference Paper
Authors
Moore, Ronald L.
(NASA Marshall Space Flight Center Huntsville, AL United States)
Falconer, David
(NASA Marshall Space Flight Center Huntsville, AL United States)
Sterling, Alphonse
(NASA Marshall Space Flight Center Huntsville, AL United States)
Whitaker, Ann F.
Date Acquired
August 20, 2013
Publication Date
January 1, 2001
Subject Category
Solar Physics
Meeting Information
Meeting: Yohkoh 10th Anniversary Meeting
Location: Kailua-Kona, HI
Country: United States
Start Date: September 17, 2001
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

Available Downloads

There are no available downloads for this record.
No Preview Available