DOI

Observed delays in the ground response to solar wind directional discontinuities have been explained as the result of larger than expected magnetosheath propagation times. Recently, Samsonov et al. (2017, https://doi.org/10.1002/2017GL075020) showed that the typical time for a southward interplanetary magnetic field (IMF) turning to propagate across the magnetosheath is 14 min. Here by using a combination of magnetohydrodynamic simulations, spacecraft observations, and analytic calculations, we study the dependence of the propagation time on solar wind parameters and near-magnetopause cutoff speed. Increases in the solar wind speed result in greater magnetosheath plasma flow velocities, decreases in the magnetosheath thickness and, as a result, decreases in the propagation time. Increases in the IMF strength result in increases in the magnetosheath thickness and increases in the propagation time. Both magnetohydrodynamic simulations and observations suggest that propagation times are slightly smaller for northward IMF turnings. Magnetosheath flow deceleration must be taken into account when predicting the arrival times of solar wind structures at the dayside magnetopause.

Original languageEnglish
Pages (from-to)3727-3741
Number of pages15
JournalJOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
Volume123
Issue number5
DOIs
StatePublished - May 2018

    Scopus subject areas

  • Forestry
  • Aquatic Science
  • Soil Science
  • Water Science and Technology
  • Earth-Surface Processes
  • Geochemistry and Petrology
  • Geophysics
  • Oceanography
  • Paleontology
  • Ecology
  • Earth and Planetary Sciences (miscellaneous)
  • Space and Planetary Science
  • Atmospheric Science

    Research areas

  • INTERPLANETARY MAGNETIC-FIELD, IONOSPHERIC CONVECTION RESPONSE, EARTHS BOW SHOCK, DAYSIDE MAGNETOPAUSE, STANDOFF DISTANCE, MHD MODEL, FLOW, DEPENDENCE, SOUTHWARD, CLUSTER, directional discontinuity, southward turning, magnetosheath reconnection, solar wind time lag

ID: 35128513