Articles | Volume 32, issue 7
Ann. Geophys., 32, 705–737, 2014
Ann. Geophys., 32, 705–737, 2014
Review paper
01 Jul 2014
Review paper | 01 Jul 2014

Dawn–dusk asymmetries in the coupled solar wind–magnetosphere–ionosphere system: a review

A. P. Walsh1, S. Haaland2,3, C. Forsyth4, A. M. Keesee5, J. Kissinger6, K. Li2, A. Runov7, J. Soucek8, B. M. Walsh6,11, S. Wing9, and M. G. G. T. Taylor10 A. P. Walsh et al.
  • 1Science and Robotic Exploration Directorate, European Space Agency, ESAC, Villanueva de la Cañada, Madrid, Spain
  • 2Max-Planck-Institute for Solar System Research, Göttingen, Germany
  • 3Birkeland Center for Space Science, University of Bergen, Bergen, Norway
  • 4UCL Department of Space and Climate Physics, Mullard Space Science Laboratory, Holmbury St. Mary, Surrey, UK
  • 5West Virginia University, Morgantown, West Virginia, USA
  • 6NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
  • 7Department of Earth and Space Sciences, UCLA, Los Angeles, California, USA
  • 8Institute of Atmospheric Physics, Czech Academy of Sciences, Prague, Czech Republic
  • 9Johns Hopkins University Applied Physics Laboratory, Maryland, USA
  • 10Science and Robotic Exploration Directorate, European Space Agency, ESTEC, Noordwijk, The Netherlands
  • 11Space Sciences Laboratory, University of California, Berkeley, USA

Abstract. Dawn–dusk asymmetries are ubiquitous features of the coupled solar-wind–magnetosphere–ionosphere system. During the last decades, increasing availability of satellite and ground-based measurements has made it possible to study these phenomena in more detail. Numerous publications have documented the existence of persistent asymmetries in processes, properties and topology of plasma structures in various regions of geospace. In this paper, we present a review of our present knowledge of some of the most pronounced dawn–dusk asymmetries. We focus on four key aspects: (1) the role of external influences such as the solar wind and its interaction with the Earth's magnetosphere; (2) properties of the magnetosphere itself; (3) the role of the ionosphere and (4) feedback and coupling between regions. We have also identified potential inconsistencies and gaps in our understanding of dawn–dusk asymmetries in the Earth's magnetosphere and ionosphere.