Research output: Contribution to journal › Article › peer-review
Magnetosheath Propagation Time of Solar Wind Directional Discontinuities. / Samsonov, A. A.; Sibeck, D. G.; Dmitrieva, N. P.; Semenov, V. S.; Slivka, K. Yu.; Safrankova, J.; Nemecek, Z.
In: JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, Vol. 123, No. 5, 05.2018, p. 3727-3741.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Magnetosheath Propagation Time of Solar Wind Directional Discontinuities
AU - Samsonov, A. A.
AU - Sibeck, D. G.
AU - Dmitrieva, N. P.
AU - Semenov, V. S.
AU - Slivka, K. Yu.
AU - Safrankova, J.
AU - Nemecek, Z.
PY - 2018/5
Y1 - 2018/5
N2 - 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.
AB - 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.
KW - INTERPLANETARY MAGNETIC-FIELD
KW - IONOSPHERIC CONVECTION RESPONSE
KW - EARTHS BOW SHOCK
KW - DAYSIDE MAGNETOPAUSE
KW - STANDOFF DISTANCE
KW - MHD MODEL
KW - FLOW
KW - DEPENDENCE
KW - SOUTHWARD
KW - CLUSTER
KW - directional discontinuity
KW - southward turning
KW - magnetosheath reconnection
KW - solar wind time lag
UR - http://www.scopus.com/inward/record.url?scp=85048884142&partnerID=8YFLogxK
UR - http://www.mendeley.com/research/magnetosheath-propagation-time-solar-wind-directional-discontinuities
U2 - 10.1029/2017JA025174
DO - 10.1029/2017JA025174
M3 - статья
VL - 123
SP - 3727
EP - 3741
JO - Journal of Geophysical Research: Biogeosciences
JF - Journal of Geophysical Research: Biogeosciences
SN - 0148-0227
IS - 5
ER -
ID: 35128513