Skip to content Skip to navigation
University of Warwick
  • Study
  • |
  • Research
  • |
  • Business
  • |
  • Alumni
  • |
  • News
  • |
  • About

University of Warwick
Publications service & WRAP

Highlight your research

  • WRAP
    • Home
    • Search WRAP
    • Browse by Warwick Author
    • Browse WRAP by Year
    • Browse WRAP by Subject
    • Browse WRAP by Department
    • Browse WRAP by Funder
    • Browse Theses by Department
  • Publications Service
    • Home
    • Search Publications Service
    • Browse by Warwick Author
    • Browse Publications service by Year
    • Browse Publications service by Subject
    • Browse Publications service by Department
    • Browse Publications service by Funder
  • Help & Advice
University of Warwick

The Library

  • Login
  • Admin

Kinematic oscillations of post-CME blobs detected by K-Cor on 2017 September 10

Tools
- Tools
+ Tools

Lee, Jae-Ok, Cho , Kyung-Suk, Nakariakov, Valery M., Lee , Harim, Kim, Rok-Soon, Jang, Soojeong, Yang, Heesu, Kim, Sujin and Kim, Yeon-Han (2021) Kinematic oscillations of post-CME blobs detected by K-Cor on 2017 September 10. Journal of The Korean Astronomical Society, 54 (2). pp. 61-70. doi:10.5303/JKAS.2021.54.2.61

[img]
Preview
PDF
WRAP-Kinematic-oscillations-post-CME-blobs-detected-K-Cor-2017-September-10-2021.pdf - Published Version - Requires a PDF viewer.
Available under License Creative Commons: Attribution-Share Alike 4.0.

Download (795Kb) | Preview
Official URL: https://doi.org/10.5303/JKAS.2021.54.2.61

Request Changes to record.

Abstract

We investigate 20 post-coronal mass ejection (CME) blobs formed in the post-CME current sheet (CS) that were observed by K-Cor on 2017 September 10. By visual inspection of the trajectories and projected speed variations of each blob, we find that all blobs except one show irregular "zigzag" trajectories resembling transverse oscillatory motions along the CS, and have at least one oscillatory pattern in their instantaneous radial speeds. Their oscillation periods are ranging from 30 to 91 s and their speed amplitudes from 128 to 902 km s-1. Among 19 blobs, 10 blobs have experienced at least two cycles of radial speed oscillations with different speed amplitudes and periods, while 9 blobs undergo one oscillation cycle. To examine whether or not the apparent speed oscillations can be explained by vortex shedding, we estimate the quantitative parameter of vortex shedding, the Strouhal number, by using the observed lateral widths, linear speeds, and oscillation periods of the blobs. We then compare our estimates with theoretical and experimental results from MHD simulations and fluid dynamic experiments. We find that the observed Strouhal numbers range from 0.2 to 2.1, consistent with those (0.15-3.0) from fluid dynamic experiments of bluff spheres, while they are higher than those (0.15-0.25) from MHD simulations of cylindrical shapes. We thus find that blobs formed in a post-CME CS undergo kinematic oscillations caused by fluid dynamic vortex shedding. The vortex shedding is driven by the interaction of the outward-moving blob having a bluff spherical shape with the background plasma in the post-CME CS.

Item Type: Journal Article
Subjects: Q Science > QB Astronomy
Divisions: Faculty of Science > Physics
Library of Congress Subject Headings (LCSH): Coronal mass ejections, Sun -- Corona, Magnetohydrodynamics, Heliosphere (Astrophysics)
Journal or Publication Title: Journal of The Korean Astronomical Society
Publisher: The Korean Astronomical Society
ISSN: 1225-4614
Official Date: 30 April 2021
Dates:
DateEvent
30 April 2021Published
8 April 2021Accepted
Volume: 54
Number: 2
Page Range: pp. 61-70
DOI: 10.5303/JKAS.2021.54.2.61
Status: Peer Reviewed
Publication Status: Published
Access rights to Published version: Open Access
RIOXX Funder/Project Grant:
Project/Grant IDRIOXX Funder NameFunder ID
2019R1F1A1055071National Research Foundation of Koreahttp://dx.doi.org/10.13039/501100003725
2019R1F1A1055071Ministry of Education (South Korea)UNSPECIFIED
ST/P000320/1[STFC] Science and Technology Facilities Councilhttp://dx.doi.org/10.13039/501100000271
UNSPECIFIEDMinistry of Education (South Korea)UNSPECIFIED
2019R1C1C1004778National Research Foundation of Koreahttp://dx.doi.org/10.13039/501100003725

Request changes or add full text files to a record

Repository staff actions (login required)

View Item View Item

Downloads

Downloads per month over past year

View more statistics

twitter

Email us: wrap@warwick.ac.uk
Contact Details
About Us