Кл.слова (ненормированные):
magnetosphere -- magnetotail configuration -- substorm -- substorm trigger -- Magnetosphere -- Orbits -- Plasma sheaths -- Solar energy -- Current sheets -- Earth's orbit -- Interplanetary magnetic fields -- Magnetospheric plasmas -- Magnetotails -- Substorm onset -- Substorms -- Wind and their effects -- Solar wind
Аннотация: We analyze two substorm onset lists, produced by different methods, and show that the (Bx·vz) product of the solar wind (SW) velocity and interplanetary magnetic field (IMF) components for two thirds of all substorm onsets has the same sign as IMF Bz. The explanation we suggest is the efficient displacement of the magnetospheric plasma sheet due to IMF Bx and SW flow vz, which both force the plasma sheet moving in one direction if the sign of (Bx·vz) correlates with the sign Bz. The displacement of the current sheet, in its turn, increases the asymmetry of the magnetotail and can alter the threshold of substorm instabilities. We study the SW and IMF data for the 15-year period (which comprises two substorm lists periods and the whole solar cycle) and reveal the similar asymmetry in the SW, so that the sign of (Bx·vz) coincides with the sign of IMF Bz during about two thirds of all the time. This disproportion can be explained if we admit that about 66% of IMF Bz component is transported to the Earth's orbit by the Alfven waves with antisunward velocities. ©2018. American Geophysical Union. All Rights Reserved.
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Держатели документа:
Earth Physics Department, Saint Petersburg State University, Saint Petersburg, Russian Federation
Institute of Computational Modelling, Federal Research Center “Krasnoyarsk Science Center SB RAS”, Akademgorodok, Russian Federation
Department of Applied Mechanics, Siberian Federal University, Krasnoyarsk, Russian Federation
Finnish Meteorological Institute, Helsinki, Finland
Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI, United States
Доп.точки доступа:
Kubyshkina, M.; Semenov, V.; Erkaev, N.; Gordeev, E.; Dubyagin, S.; Ganushkina, N.; Shukhtina, M.