Explicit IMF By-dependence of magnetospheric energetic protons and the ring current
- 1Space Physics and Astronomy Research Unit, University of Oulu, Oulu, Finland
- 2Department of Astronomy, University of Maryland, College Park, MD, USA
- 3NASA Goddard Space Flight Center, Greenbelt, MD, USA
The interaction of the solar wind with the Earth’s magnetic field produces geomagnetic activity, which is critically dependent on the orientation of the interplanetary magnetic field (IMF). While the dawn-dusk (By) component of the IMF is known to play an important role in this interaction, its effects are usually assumed to be independent of its sign. However, recent studies have shown that auroral electrojets and substorm activity are stronger for By < 0 in Northern Hemisphere (NH) summer. This so-called explicit By-dependence is reversed for NH winter. Here we study how IMF By modulates magnetospheric energetic protons and the ring current by using measurements of NOAA POES satellites and the Comprehensive Inner Magnetosphere-Ionosphere (CIMI) model coupled in with the global BATSRUS MHD code. We show that the energetic magnetospheric protons and the ring current (Dst index) exhibit an explicit By-dependence (stronger for By < 0 in NH summer), which can be reproduced by the model. Our results highlight the importance of the IMF By component for space weather and must be taken into account in the future space weather modeling.
How to cite: Holappa, L. and Buzulukova, N.: Explicit IMF By-dependence of magnetospheric energetic protons and the ring current, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-11257, https://doi.org/10.5194/egusphere-egu22-11257, 2022.
