Solar Physics

, Volume 264, Issue 1, pp 119–147 | Cite as

Revealing the Fine Structure of Coronal Dimmings and Associated Flows with Hinode/EIS

Implications for Understanding the Source Regions of Sustained Outflow Following CMEs
  • G. D. R. AttrillEmail author
  • L. K. Harra
  • L. van Driel-Gesztelyi
  • M. J. Wills-Davey


We study two CME events on 13 and 14 December 2006 that were associated with large-scale dimmings. We study the eruptions from pre-event on 11 December through the recovery on 15 December, using a combination of Hinode/EIS, SOHO/EIT, SOHO/MDI, and MLSO Hα data. The GOES X-class flares obscured the core dimmings, but secondary dimmings developed remote from the active region (AR) in both events. The secondary dimmings are found to be formed by a removal of bright coronal material from loops in the plage region to the East of the AR. Using Hinode/EIS data, we find that the outflows associated with the coronal-dimming regions are highly structured. The concentrated outflows are located at the footpoints of coronal loops (which exist before, and are re-established after, the eruptions), and these are correlated with regions of positive magnetic elements. Comparative study of the Hinode/EIS and SOHO/EIT data shows that the reduction in outflow velocity is consistent with the recovery in intensity of the studied regions. We find that concentrated downflows develop during the recovery phase of the dimmings and are also correlated with the same positive magnetic elements that were previously related to outflows.

The local behaviour of the flows in and around the dimming regions following the eruptions is found to be dynamic and complex. Despite the global aspects of these events (widespread dimmings, CMEs, coronal waves) being largely homologous, there are significant local variations and distinct differences between the flows associated with the two events. We find that the secondary dimmings recover primarily by re-establishment of the bright coronal loops (the exact configuration changes between the eruptions, which is reflected by the complexity of the flows).


Coronal Mass Ejection Solar Phys Coronal Hole Coronal Loop Coronal Wave 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Supplementary material

Hα movie: (MOV 38.9 MB)


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Copyright information

© Springer Science+Business Media B.V. 2010

Authors and Affiliations

  • G. D. R. Attrill
    • 1
    Email author
  • L. K. Harra
    • 2
  • L. van Driel-Gesztelyi
    • 2
    • 3
    • 4
  • M. J. Wills-Davey
    • 1
  1. 1.Harvard-Smithsonian Center for AstrophysicsCambridgeUSA
  2. 2.UCL-Mullard Space Science LaboratoryDorkingUK
  3. 3.Observatoire de Paris, LESIA, UMR 8109CNRSMeudon Principal CedexFrance
  4. 4.Konkoly Observatory of the Hungarian Academy of SciencesBudapestHungary

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