Large-scale energy budget of impulsive magnetic reconnection: Theory and simulation
DOI:
10.1002/2016JA023169URI (для ссылок/цитирований):
http://onlinelibrary.wiley.com/doi/10.1002/2016JA023169/abstracthttps://elib.sfu-kras.ru/handle/2311/69857
Автор:
Kiehas, S. A.
Volkonskaya, N. N.
Semenov, V. S.
Еркаев, Николай Васильевич
Kubyshkin, I. V.
Zaitsev, I. V.
Коллективный автор:
Политехнический институт
Кафедра прикладной механики
Дата:
2017-03Журнал:
Journal of Geophysical ResearchКвартиль журнала в Scopus:
Q1Квартиль журнала в Web of Science:
Q1Библиографическое описание:
Kiehas, S. A. Large-scale energy budget of impulsive magnetic reconnection: Theory and simulation [Текст] / S. A. Kiehas, N. N. Volkonskaya, V. S. Semenov, Николай Васильевич Еркаев, I. V. Kubyshkin, I. V. Zaitsev // Journal of Geophysical Research. — 2017. — Т. 122 (№ 3). — С. 3212-3231Аннотация:
We evaluate the large-scale energy budget of magnetic reconnection utilizing an
analytical time-dependent impulsive reconnection model and a numerical 2-D MHD simulation. With the
generalization to compressible plasma, we can investigate changes in the thermal, kinetic, and magnetic
energies. We study these changes in three different regions: (a) the region defined by the outflowing
plasma (outflow region, OR), (b) the region of compressed magnetic fields above/below the OR (traveling
compression region, TCR), and (c) the region trailing the OR and TCR (wake). For incompressible plasma,
we find that the decrease inside the OR is compensated by the increase in kinetic energy. However, for the
general compressible case, the decrease in magnetic energy inside the OR is not sufficient to explain the
increase in thermal and kinetic energy. Hence, energy from other regions needs to be considered. We find
that the decrease in thermal and magnetic energy in the wake, together with the decrease in magnetic
energy inside the OR, is sufficient to feed the increase in kinetic and thermal energies in the OR and the
increase in magnetic and thermal energies inside the TCR. That way, the energy budget is balanced, but
consequently, not all magnetic energy is converted into kinetic and thermal energies of the OR. Instead,
a certain fraction gets transfered into the TCR. As an upper limit of the efficiency of reconnection (magnetic
energy → kinetic energy) we find 𝜂eff =1∕2. A numerical simulation is used to include a finite thickness of
the current sheet, which shows the importance of the pressure gradient inside the OR for the conversion
of kinetic energy into thermal energy.