Anemone Structure of AR NOAA 10798 and Related Geo-Effective Flares and CMEs

of 17
All materials on our website are shared by users. If you have any questions about copyright issues, please report us to resolve them. We are always happy to assist you.
Information Report
Category:

Documents

Published:

Views: 94 | Pages: 17

Extension: PDF | Download: 0

Share
Description
Anemone Structure of AR NOAA 10798 and Related Geo-Effective Flares and CMEs. A. Asai 1 ( 浅井 歩 ), T.T. Ishii 2 , K. Shibata 2 , N. Gopalswamy 3 1: Nobeyama Solar Radio Observatory, NAOJ 2: Kyoto University 3: NASA/GSFC. COSPAR2006-A-02406; D2.1-0023-06
Transcript
Anemone Structure of AR NOAA 10798 and Related Geo-Effective Flares and CMEsA. Asai1(浅井 歩), T.T. Ishii2, K. Shibata2, N. Gopalswamy31: Nobeyama Solar Radio Observatory, NAOJ2: Kyoto University3: NASA/GSFCCOSPAR2006-A-02406; D2.1-0023-06COSPAR 2006, Beijing, China 2006-July-19Today’s TopicFlare
  • A magnetic storm (2005 August 24) and the related events
  • Birth and evolution of AR NOAA 10798
  • Flares and CMEs (2005 August 22)
  • Magnetic storm (2005 August 24)
  • Focusing on the features of the sun (photosphere and corona)
  • CMEDst Indexmagnetic stormnTDst ~ 216 nT8/23 24 25 26 27Birth & Evolution of NOAA 10798emergence!movie of SOHO/MDI magnetogramFeature of NOAA 10798Emerged pair violates the Hale’s polarity law!the order of N/S polarity regions with respect to the east-west direction is determined in a given hemisphereSNSNhighly twisted magnetic structure lies beneath the photosphere!?generate X17 flare in the next rotationNOAA 10798NSSNSoft X-Ray Lightcurve (GOES)
  • 3 M-class flare occurred
  • We focus on the first 2 flares on 2005-Aug-22
  • emergence22-AugNear southwest limbflare1: (S11 W54)flare2: (S12 W60)Both are long duration events (LDEs)Clear arcade structure can be seen2 M-Class Flaresflare2M5.6flare1M2.6Movie of SOHO/EIT (195A)Associated with the flares, Halo-type CMEs occurred08/22 01h (flare1: M2.6)CME1: 1200 km/s08/22 17h (flare2: M5.6)CME2: 2400 km/svery fast CME!Time interval is ~16hours, but the 2nd CME may catch up the 1st one2 Halo-CMEsSOHO/LASCO C350n [cm-3]Interplanetary Disturbance700V [km/s]
  • ACE data
  • shock: 8/24 05:30UT
  • very complex structure
  • strong southward magnetic field: –50 nT
  • merging of 2 CMEs?
  • CIR + shock?
  • 50|B| [nT]Bx [nT]By [nT]Bz [nT]–50DstEvent Summary
  • 2 LDE flares occurred on 2005 August 22
  • NOAA 10798 was close to the west limb (W60)
  • Halo-type CMEs
  • The 2nd CME is especially fast (2400 km/s)
  • Strong southward magnetic field region
  • What was the origin of the southward magnetic field?
  • Why did halo-type CMEs occur regardless of the near-limb position?
  • Why were so fast CMEs?
  • Examine the features of the active region in more detailSouthward Magnetic Field?Ha image obtained with SMART of Kyoto Univ.
  • From Ha images, we can identify a filament whose axial field directs south
  • on 2006 August 21NSSOHO/MDIAnemone Structure
  • anemone structure: active region that appears inside a coronal hole
  • nest of (gigantic) jets (not so active)
  • anemone structuresea anemoneCHSOHO/EIT 195A imageAnemone Structure and Flares/CMEs
  • For a small AR, CH works to collimate the ejections
  • In the case of NOAA 10798, a small CH and quite a big AR…
  • Low magnetic pressure above the AR
  • Easy for ejections to expand
  • Halo CMEsHigh speed CMEsAR: active regionCH: coronal holeSummary
  • NOAA 10798
  • has a potentially complex structure (violating the Hale’s polarity law)
  • emerged in a small coronal hole  anemone structure
  • formed filaments, whose the axial field is southward
  • generated 3 M-class flares (2005 August 22–23),
  • followed by Halo-type CMEs
  • CMEs are very fast, and are widely spread
  • strong southward magnetic field (2 CMEs / CIR + shock)
  • big magnetic storm (2005 August 24)Thank you!Longitudes of Storm-related CMEsN37/55 = 67%18/55 = 33%15WSEPEWSEast-West Asymmetry of solar sources is confirmed(Wang et al. 2002; Zhang et al. 2003)Larger storms (Dst < -200 nT) seem to occur Close to the disk center (±15 deg)ODst < - 200 nTO - 300nT < Dst < - 200 nTO Dst < - 300 nTSEPイベントCoronal Features of NOAA 10798
  • SOHO/EIT (195A)
  • NOAA 1079810797CHNew AR appears in a small coronal hole
    Recommended
    View more...
    We Need Your Support
    Thank you for visiting our website and your interest in our free products and services. We are nonprofit website to share and download documents. To the running of this website, we need your help to support us.

    Thanks to everyone for your continued support.

    No, Thanks