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Annales Geophysicae An interactive open-access journal of the European Geosciences Union
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Volume 27, issue 7
Ann. Geophys., 27, 2771–2777, 2009
© Author(s) 2009. This work is distributed under
the Creative Commons Attribution 3.0 License.

Special issue: Three eyes on the Sun – multi-spacecraft studies of...

Ann. Geophys., 27, 2771–2777, 2009
© Author(s) 2009. This work is distributed under
the Creative Commons Attribution 3.0 License.

  13 Jul 2009

13 Jul 2009

Coronal magnetic fields inferred from IR wavelength and comparison with EUV observations

Y. Liu Y. Liu
  • Yunnan Astronomical Observatory, National Astronomical Observatories, Kunming 650011, China
  • Institute for Astronomy, University of Hawaii, 34 Ohia Ku Street, Pukalani, HI 96768, USA

Abstract. Spectropolarimetry using IR wavelength of 1075 nm has been proved to be a powerful tool for directly mapping solar coronal magnetic fields including transverse component directions and line-of-sight component intensities. Solar tomography, or stereoscopy based on EUV observations, can supply 3-D information for some magnetic field lines in bright EUV loops. In a previous paper \citep{liu08} the locations of the IR emission sources in the 3-D coordinate system were inferred from the comparison between the polarization data and the potential-field-source-surface (PFSS) model, for one of five west limb regions in the corona (Lin et al., 2004). The paper shows that the region with the loop system in the active region over the photospheric area with strong magnetic field intensity is the region with a dominant contribution to the observed Stokes signals. So, the inversion of the measured Stokes parameters could be done assuming that most of the signals come from a relatively thin layer over the area with a large photospheric magnetic field strength. Here, the five limb coronal regions are studied together in order to study the spatial correlation between the bright EUV loop features and the inferred IR emission sources. It is found that, for the coronal regions above the stronger photospheric magnetic fields, the locations of the IR emission sources are closer to or more consistent with the bright EUV loop locations than those above weaker photospheric fields. This result suggests that the structures of the coronal magnetic fields observed at IR and EUV wavelengths may be different when weak magnetic fields present there.

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