Труды сотрудников ИВМ СО РАН

[Text] / N. V. Erkaev [et al.] // STREAMERS, SLOW SOLAR WIND, AND THE DYNAMICS OF THE MAGNETOSPHERE. Ser. ADVANCES IN SPACE RESEARCH : PERGAMON-ELSEVIER SCIENCE LTD, 2004. - Vol. 33: 2nd World Space Congress/34th COSPAR Scientific Assembly (OCT 10-19, 2002, HOUSTON, TX), Is. 5. - P784-788, DOI 10.1016/S0273-1177(03)00646-X. - Cited References: 13 . - ISBN 0273-1177РУБ Engineering, Aerospace + Astronomy & Astrophysics + Geosciences, Multidisciplinary + Meteorology & Atmospheric Sciences

Аннотация: The interplanetary magnetic field is enhanced in a thin layer near the magnetopause which is called the magnetic barrier or plasma depletion layer. The magnetic energy stored in the magnetic barrier can be released during the process of magnetic field reconnection. Using ideal magnetohydrodynamics and assuming a sudden decrease of the magnetic field near the magnetopause due to the reconnection pulse, we analyze the model variations of the plasma parameters and the magnetic field at the magnetosheath. For a given reconnection rate and calculated parameters of the magnetic barrier, we derive the duration of a reconnection pulse as a function of the solar wind parameters. (C) 2003 COSPAR. Published by Elsevier Ltd. All rights reserved.


Доп.точки доступа:
Erkaev, N.V.; Еркаев, Николай Васильевич; Farrugia, C.J.; Biernat, H.K.; Langmayr, D.

[Text] / N. V. Erkaev, C. J. Farrugia, H. K. Biernat // Planet Space Sci. - 2003. - Vol. 51, Is. 12. - P745-755, DOI 10.1016/S0032-0633(03)00111-9. - Cited References: 36 . - ISSN 0032-0633РУБ Astronomy & Astrophysics

Аннотация: The magnetized solar wind carries a large amount of energy but only a small fraction of it enters the magnetosphere and powers its dynamics. Numerous observations show that the interplanetary magnetic field (IMF) is a key parameter regulating the solar wind-magnetosphere interaction. The main factor determining the amount of energy extracted from the solar wind flow by the magnetosphere is the plasma flow structure in the region adjacent to the sunward side of the magnetopause. While compared to the energy of the solar wind flow the IMF magnetic energy is relatively weak, it is considerably enhanced in a thin layer next to the dayside magnetopause variously called the plasma depletion layer or magnetic barrier. Important features of this barrier/layer are (i) a pile-up of the magnetic field with (ii) a concurrent decrease of density, (iii) enhancement of proton temperature anisotropy, (iv) asymmetry of plasma flow caused by magnetic field tension. and (v) characteristic wave emissions (ion cyclotron waves). Importantly, the magnetic barrier can be considered as an energy source for magnetic reconnection. While the steady-state magnetic barrier has been extensively examined, non-steady processes therein have only been addressed by a few authors. We discuss here two non-steady aspects related to variations of the magnetic barrier caused by (i) a north-to-south rotation of the IMF, and (ii) by pulses of magnetic field reconnection at the magnetopause. When the IMF rotates smoothly from north-to-south, a transition layer is shown to appear in the magnetosheath which evolves into a thin layer bounded by sharp gradients in the magnetic field and plasma quantities. For a given reconnection rate and calculated parameters of the magnetic barrier, we estimate the duration and length scale of a reconnection pulse as a function of the solar wind parameters. Considering a sudden decrease of the magnetic field near the magnetopause caused by the reconnection pulse, we study the relaxation process of the magnetic barrier. We find that the relaxation time is longer than the duration of the reconnection pulse for large Alfved-Mach numbers. (C) 2003 Elsevier Ltd. All rights reserved.


Доп.точки доступа:
Erkaev, N.V.; Еркаев, Николай Васильевич; Farrugia, C.J.; Biernat, H.K.