Solar Physics

, Volume 256, Issue 1, pp 345–363

Effects of the Weak Polar Fields of Solar Cycle 23: Investigation Using OMNI for the STEREO Mission Period

  • C. O. Lee
  • J. G. Luhmann
  • X. P. Zhao
  • Y. Liu
  • P. Riley
  • C. N. Arge
  • C. T. Russell
  • I. de Pater
Open AccessSTEREO SCIENCE RESULTS AT SOLAR MINIMUM

DOI: 10.1007/s11207-009-9345-6

Cite this article as:
Lee, C.O., Luhmann, J.G., Zhao, X.P. et al. Sol Phys (2009) 256: 345. doi:10.1007/s11207-009-9345-6

Abstract

The current solar cycle minimum seems to have unusual properties that appear to be related to weak solar polar magnetic fields. We investigate signatures of this unusual polar field in the ecliptic near-Earth interplanetary magnetic field (IMF) for the STEREO period of observations. Using 1 AU OMNI data, we find that for the current solar cycle declining phase to minimum period the peak of the distribution for the values of the ecliptic IMF magnitude is lower compared to a similar phase of the previous solar cycle. We investigate the sources of these weak fields. Our results suggest that they are related to the solar wind stream structure, which is enhanced by the weak polar fields. The direct role of the solar field is therefore complicated by this effect, which redistributes the solar magnetic flux at 1 AU nonuniformly at low to mid heliolatitudes.

Keywords

STEREO missionSolar windSolar cycle, modelsSolar cycle, observationsMagnetic fields, observationsMagnetic fields, interplanetary
Download to read the full article text

Copyright information

© The Author(s) 2009

Authors and Affiliations

  • C. O. Lee
    • 1
    • 2
  • J. G. Luhmann
    • 1
  • X. P. Zhao
    • 3
  • Y. Liu
    • 3
  • P. Riley
    • 4
  • C. N. Arge
    • 5
  • C. T. Russell
    • 6
  • I. de Pater
    • 2
  1. 1.Space Sciences LaboratoryUniversity of CaliforniaBerkeleyUSA
  2. 2.Department of Earth and Planetary ScienceUniversity of CaliforniaBerkeleyUSA
  3. 3.W. W. Hansen Experimental Physics LaboratoryStanford UniversityStanfordUSA
  4. 4.Predictive Science, Inc.San DiegoUSA
  5. 5.Air Force Research Laboratory/Space Vehicles DirectorateKirtland Air Force BaseUSA
  6. 6.Institute of Geophysics and Planetary PhysicsUniversity of CaliforniaLos AngelesUSA