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Action Team: Coronal Hole Boundary Working Team

Team ID: S2-01

Team Leads:

Lead: Martin Reiss (NASA/GSFC, USA),

Co-Lead: Karin Muglach (NASA/GSFC, USA),


The ambient solar wind flows, and the magnetic fields embedded within it, are driven by the Sun's magnetic field. Thus, studying the magnetic field configuration in the solar atmosphere is of key importance for improving the understanding and ultimately improve the predictions of the evolving space weather from Sun to Earth. The magnetic configuration of open field lines along which solar wind flows accelerate to supersonic speeds, commonly known as coronal holes, is especially important for predicting key properties in the interplanetary space such as solar wind bulk speed, magnetic field strength, and field orientation. Additionally, the dynamic evolution of coronal hole boundaries is understood as having a critical role in the origin of the slow solar wind. Coronal holes in EUV and X-Ray images are an important diagnostic of the magnetic field configuration of the Sun and are a key observational test for numerical models of the ambient solar wind. Despite the importance of these solar phenomena, there has been no detailed investigation of the strengths and weaknesses of automated coronal hole detection schemes. 


The objectives of this action team are threefold: First, to study and compare different automated coronal hole detection schemes with open communication with the space weather community. Second, to develop strategies to quantitatively assess the spatial and temporal uncertainty of coronal hole boundary locations. Third, to use this information to further improve the predictive capabilities of ambient solar wind models.

Action Items:

  • Establish a database of CH candidates based on different automated coronal hole detection schemes.
  • Define metrics to assess the uncertainty of coronal hole boundaries in EUV and X-Ray images of the Sun to better understand the advantages/disadvantages of these techniques.
  • Develop strategies to assess the uncertainty of CH boundary locations in ambient solar wind models.
  • Develop strategies to inform/constrain ambient solar wind models and enhance their predictive capabilities.


  • The Observational Uncertainty of Coronal Hole Boundaries in Automated Detection Schemes. M. A. Reiss, K. Muglach, C. Möstl, C. N. Arge, R. Bailey, V. Delouille, T. M. Garton, A. Hamada, S. Hofmeister, E. Illarionov, R. Jarolim, M. Kirk, A. Kosovichev, L. Krista, S. Lee, C. Lowder, P. J. MacNeice, A. Veronig, and Coronal Hole Boundary Working Team Members. The Astrophysical Journal, March 2021. [Open Access]


Show/Hide Team S2-01 Participants

Lucia Abbo (INAF - Osservatorio Astrofisco di Torino, Italy)
C. Nick Arge (NASA/GSFC, USA)
Stefano Bianco (GFZ Potsdam, GERMANY)
Laura Boucheron (New Mexico State University, USA)
Ronald Caplan (Predictive Science Inc., USA)
Shibaji Chakraborty (Virginia Tech, USA)
Yaireska Collado-Vega (NASA/GSFC, USA)
Joaquim Costa (INPE - National Institute for Space Research, BRAZIL)
Ligia Alves Da Silva (INPE - National Institute for Space Research, BRAZIL)
Daniel da Silva (NASA/GSFC, USA)
Jeremy Grajeda (New Mexico State University, USA)
Amr Hamada (National Solar Observatory, USA)
Stephan Heinemann (University of Helsinki, FINLAND)
Carl Henney (AFRL - Air Force Research Laboratory, USA)
K M Hiremath (Indian Institute of Astrophysics, Bengaluru-560034, India)
Stefan Hofmeister (Polar Geophysical Institute, Apatity, Russia)
Egor Illarionov (Lomonosov Moscow State University, RUSSIA)
Fadil Inceoglu (GFZ Potsdam, GERMANY)
Robert Jarolim (University of Graz, AUSTRIA)
Jaehun Kim (Korean Space Weather Center, KOREA)
Michael Kirk (NASA/GSFC, USA)
Yuan-Kuen Ko (NRL - Naval Research Laboratory, USA)
Alexander Kosovichev (New Jersey Institute of Technology, USA)
Jaime Landeros (ADNET Systems Inc., USA)
Sangwoo Lee (Korean Space Weather Center, KOREA)
Jon Linker (Predictive Science Inc., USA)
Chris Lowder (Southwest Research Institute, USA)
Janet Luhmann (UC Berkeley - University of California Berkeley)
Simon Mackovjak (Institute of Experimental Physics, Slovak Academy of Sciences)
Peter MacNeice (NASA/NSF Community Coordinated Modeling Center (CCMC), USA)
Maria Madjarska (Max-Planck Institute for Solar System Research, Germany)
Jasmina Magdalenic (KU Leuven, BELGIUM)
Emily Mason (NASA/GSFC, USA)
Simon Mockovjak (Institute of Experimental Physics, Slovak Academy of Sciences)
Karin Muglach (NASA/GSFC, USA)
Nawin Ngampoopun (MSSL - Mullard Space Science Laboratory, University College London, UK)
Nariaki Nitta (LMSAL - Lockheed Martin Solar and Astrophysics Laboratory, USA)
Olga Panasenco (Advanced Heliophysics Inc., Pasadena CA, USA)
Isabell Piantschitsch (University of the Balearic Islands (UIB), Spain)
Martin Reiss (Space Research Institute - SRI, Graz, AUSTRIA)
Evangelia Samara (NASA/GSFC, USA)
Samuel Schonfeld (AFRL - Air Force Research Laboratory, USA)
Dibyendu Sur (University of Colorado / SWx TREC, USA)
Manuela Temmer (University of Graz, AUSTRIA)
Vadim Uritsky (CUA - Catholic University of America, USA)
Astrid Veronig (University of Graz, AUSTRIA)
Erwin Verwichte (University of Warwick, UK)
Yi-Ming Wang (NRL - Naval Research Laboratory, USA)