University of Oulu

On a limitation of Zeeman polarimetry and imperfect instrumentation in representing solar magnetic fields with weaker polarization signal. A.A. Pevtsov, Y. Liu, I. Virtanen, L. Bertello, K. Mursula, K.D. Leka, A.L.H. Hughes, J. Space Weather Space Clim. 11 14 (2021), DOI: 10.1051/swsc/2021003

On a limitation of Zeeman polarimetry and imperfect instrumentation in representing solar magnetic fields with weaker polarization signal

Saved in:
Author: Pevtsov, A. A.1; Liu, Y.2; Virtanen, I.3;
Organizations: 1National Solar Observatory, 3665 Discovery Drive, 3rd Floor, Boulder, CO 80303, USA
2Stanford University, Stanford, CA 94305-4085, USA
3ReSoLVE Centre of Excellence, Space Climate Research Unit, University of Oulu, POB 3000, 90014 Oulu, Finland
4NorthWest Research Associates, 3380 Mitchell Lane, Boulder, CO 80301, USA
5Institute for Space-Earth Environmental Research, Nagoya University, Furo-cho Chikusa-ku Nagoya, 464-8601 Aichi, Japan
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 1 MB)
Persistent link:
Language: English
Published: EDP Sciences, 2021
Publish Date: 2021-04-29


Full disk vector magnetic fields are used widely for developing better understanding of large-scale structure, morphology, and patterns of the solar magnetic field. The data are also important for modeling various solar phenomena. However, observations of vector magnetic fields have one important limitation that may affect the determination of the true magnetic field orientation. This limitation stems from our ability to interpret the differing character of the Zeeman polarization signals which arise from the photospheric line-of-sight vs. the transverse components of the solar vector magnetic field, and is likely exacerbated by unresolved structure (non-unity fill fraction) as well as the disambiguation of the 180° degeneracy in the transverse-field azimuth. Here we provide a description of this phenomenon, and discuss issues, which require additional investigation.

see all

Series: Journal of space weather and space climate
ISSN: 2115-7251
ISSN-E: 2115-7251
ISSN-L: 2115-7251
Volume: 11
Article number: 14
DOI: 10.1051/swsc/2021003
Type of Publication: A1 Journal article – refereed
Field of Science: 115 Astronomy and space science
Funding: The authors thank Robert Cameron for his thoughtful comments, which helped improving this article. We acknowledge help by Alexander Pevtsov in preparation of the manuscript. This work is the result of discussions held at three working meetings on the “Use of Vector Synoptic Maps for Modeling”. Funding for these meetings was provided by the hosting groups at the University of Oulu, Finland; the National Solar Observatory, USA; the Max Planck Institute for Solar System Research, Germany; and by NASA’s Solar Dynamics Observatory (Dr. Dean Pesnell). We also acknowledge the financial support by the Academy of Finland to the ReSoLVE Centre of Excellence (project no. 307411). AAP and LB acknowledge partial support by NASA grants 80NSSC17K0686 and NNX15AN43G. KDL acknowledges partial support from NASA/GSFC grant 80NSSC19K0317. This work utilizes SOLIS data obtained by the NSO Integrated Synoptic Program (NISP), managed by the National Solar Observatory. HMI data used here are courtesy of NASA/SDO and the HMI science teams. The editor thanks two anonymous reviewers for their assistance in evaluating this paper.
Academy of Finland Grant Number: 307411
Detailed Information: 307411 (Academy of Finland Funding decision)
Copyright information: © A.A. Pevtsov et al., Published by EDP Sciences 2021. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.