1 / 21

Flaring Hale Sector Boundaries

Flaring Hale Sector Boundaries. Leif Svalgaard 3 June, 2011. Almost 37 years ago one of our students published this paper in Solar Physics. Flares seemed to cluster near a specific type of sector boundary. Almost all the activity for that time was in the Northern Hemisphere.

bshelor
Download Presentation

Flaring Hale Sector Boundaries

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Flaring Hale Sector Boundaries Leif Svalgaard 3 June, 2011

  2. Almost 37 years ago one of our students published this paper in Solar Physics

  3. Flares seemed to cluster near a specific type of sector boundary

  4. Almost all the activity for that time was in the Northern Hemisphere

  5. Dittmer concluded Similar things were seen by others at the time

  6. This prompted John Wilcox and myself to take a closer look

  7. We remarked that Now, 35 years later that is unfortunately still the case

  8. What is a Hale Boundary? A Hale Boundary is that part of a solar sector boundary where the change of polarity matches that of active regions in that hemisphere ‘Sector Boundary’ has gone out of use. ‘Neutral Line’ may be a more familiar term

  9. Sector Boundaries are places with magnetic arcades of closed field lines Trapping the coronal plasma in high-density structures that we can ‘see’

  10. Green Fe XIV Coronal Brightnessis associated with Active Regions [and more] ? ? Altrock, 2009

  11. What we would predict from Dittmer’s [and other’s] finding did manifest itself in the Green Corona It was brighter over Hale boundaries

  12. The Coronal Excess Brightness over Hale Boundaries switches abruptly at solar minimum

  13. The Photospheric Magnetic Field [MWO] is at a maximum at the Hale Boundary Magnitude of the field measured at Mt. Wilson

  14. And then this line of inquiry died

  15. Until I took a look using WSO data

  16. Flipping and Sign-Reversing Building a nominal average magnetogram for a (-,+) boundary at Central Meridian. A Synchronic Image

  17. Having Lunch at UCB • I told Hugh Hudson about the Hale Boundary concept and Phil Dittmer’s finding about flares and Hale Boundaries • Hugh didn’t believe there was anything to it. Flares should not be organized that way. • I proposed a test using the thousands of flares observed by RHESSI

  18. This is what he [and Iain Hannah] found, using all RHESSI flares during 2002-2008 The circles mark where I predicted fewer flares…

  19. We eventually published this result After some fight with [as Hugh put it] a ‘crafty’ referee

  20. Prettied up Figures RHESSI flare list NOAA flare list

  21. Looking at the GWILL Hale Non-Hale

More Related