EGU General Assembly 2020
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

The forming slow solar wind imaged along streamer rays by the wide-angle imager on Parker Solar Probe

Nicolas Poirier1, Athanasios Kouloumvakos1, Alexis P. Rouillard1, Rui Pinto1, Angelos Vourlidas2, Guillermo Stenborg3, Emeline Valette1, Russell A. Howard3, Phillip Hess3, Arnaud Thernisien3, Nathan Rich3, Léa Griton1, Mikel Indurain1, Nour-Edine Raouafi2, Michael Lavarra1, and Victor Réville1
Nicolas Poirier et al.
  • 1IRAP, Université Toulouse III - Paul Sabatier, CNRS, CNES, Toulouse, France
  • 2John Hopkins APL, Laurel, USA
  • 3Naval Research Laboratory, Washington DC, USA

The Wide-field Imager for Solar PRobe (WISPR) obtained the first high-resolution images of coronal rays at heights below 15 Rsun when Parker Solar Probe (PSP) was located inside 0.25 AU during the first encounter. We exploit these remarkable images to reveal the structure of coronal rays at scales that are not easily discernible in images taken from near 1 AU. To analyze and interpret WISPR observations which evolve rapidly both radially and longitudinally, we construct a latitude versus time map using full WISPR dataset from the first encounter. From the exploitation of this map and also from sequential WISPR images we show the presence of multiple sub-structures inside streamers and pseudo-streamers. WISPR unveils the fine-scale structure of the densest part of streamer rays that we identify as the solar origin of the heliospheric plasma sheet typically measured in situ in the solar wind. We exploit 3-D magneto-hydrodynamic (MHD) models and we construct synthetic white-light images to study the origin of the coronal structures observed by WISPR. Overall, including the effect of the spacecraft relative motion towards the individual coronal structures we can interpret several observed features by WISPR. Moreover, we relate some coronal rays to folds in the heliospheric current sheet that are unresolved from 1 AU. Other rays appear to form as a result of the inherently inhomogeneous distribution of open magnetic flux tubes. This work was funded by the European Research Council through the project SLOW_SOURCE - DLV-819189.

How to cite: Poirier, N., Kouloumvakos, A., Rouillard, A. P., Pinto, R., Vourlidas, A., Stenborg, G., Valette, E., Howard, R. A., Hess, P., Thernisien, A., Rich, N., Griton, L., Indurain, M., Raouafi, N.-E., Lavarra, M., and Réville, V.: The forming slow solar wind imaged along streamer rays by the wide-angle imager on Parker Solar Probe, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-11552,, 2020.


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displays version 3 – uploaded on 06 May 2020
Added reference in slide 8.
  • CC1: Comment on EGU2020-11552, Yuri Yermolaev, 08 May 2020

    At the request of a colleague, I post his comment

    Interesting presentation. 
    It is important that your result confirm our result published several years ago. 
    Eselevich, M. V.; Eselevich, V. G.The Structure of the Coronal-Streamer Belt. Astronomy Reports, 2005, vol. 48, Issue 1, p.71-78 
     Eselevich, M. V.; Eselevich, V. G. Fractal Structure of the Heliospheric Plasma Sheet in the Earth's Orbit // Geomagnetism and Aeronomy, Vol. 45, No. 3, 2005, pp. 326–336.
     Eselevich, M. V.; Eselevich, V. G.. Some Features of the Streamer Belt in the Solar Corona and at the Earth's Orbit. Astronomy Reports, 2006, Vol. 50, No. 9, pp. 748–761.
    Eselevich M.V., Eselevich V.G. The double structure of the coronal streamer belt.  Solar Physics, v.235, p. 331-344,  2006.
    V.G. Eselevich. Exploring the Solar Wind. Chapter 1: Solar Wind Laws Valid for any Phase of a Solar Cycle, edited by Marian Lazar, INTECH, March, 2012, p. 3-28.
    V.G. Eselevich.  Diamagnetic structure as a basc of quasi-ststionary slow solar wind// Solar-Terrestrial Physics.  2019. Vol. 5. Iss. 3. P. 29–41. DOI: 10.12737/stp-53201904
    Best regards, 
    Victor Eselevich

displays version 2 – uploaded on 04 May 2020, no comments
Just modified the first (title) slide.
displays version 1 – uploaded on 28 Apr 2020, no comments