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Astrophysics Research Centre

School of Mathematics and Physics


Evolution of Peripheral Active Region Plasma Upflows over the Solar Cycle

  • Submitted by: Len Culhane, UCL-Mullard Space Science Laboratory
  • Authors: D. Baker, D. Weston, J.L. Culhane, L. van Driel-Gesztelyi, L.K. Harra
  • Session: Monday morning posters.

Discovery by the Hinode EUV Spectrometer (EIS) of persistent plasma upflows from Active Region (AR) peripheries raises the question of how these flows evolve with solar cycle changes. Using the Hinode/EIS instrument, we have studied the properties of plasma upflows for a large group of ARs selected for detailed observations in the interval JAN 2006 to JUL 2014 (Cycle 23/24). Observing at or near central meridian passage, we have measured for upflow plasma in each AR, Fe XII line intensity (I), velocity (v), non-thermal velocity (vnt), electron temperature (Te), and electron density (ne) where the latter two parameters were obtained from appropriate Fe XIII line pair ratios. Magnetic field configurations were determined for each of the upflow regions using either SOHO/MDI or SDO/HMI magnetograms and their relationship to the upflows was examined. AR size and evolutionary stage were assessed and the association of these properties with the observed plasma upflow behaviour will be discussed. Following the presentation of all of these data on upflowing plasma, an assessment of how the properties of this material are influenced by the progression of the solar cycle over an eight year interval will be made. Given that these flows are likely to provide a significant contribution to the slow solar wind, the nature of any cycle dependent influence on the slow wind contribution will also be discussed.

Click here to download pdf of eposter

public/hinode9/schedule/session-01p/v0010.txt · Last modified: 2015/09/26 11:45 by Mihalis Mathioudakis


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