TY - JOUR

T1 - Unsteady Dungey cycle from the point of view of Stokes’ theorem

AU - Semenov, Vladimir S.

AU - Kubyshkin, Igor V.

AU - Tsyganenko, Nikolai A.

AU - Erkaev, Nikolai V.

AU - Kubyshkina, Marina V.

AU - Wang, Xiaogang

PY - 2024/12/10

Y1 - 2024/12/10

N2 - The Dungey cycle is considered from the formation of a magnetic barrier andnecessary for dayside reconnection conditions till the electric field generationaround the Birkeland current loop and magnetic flux circulation balance. Data based modeling of the magnetosheath magnetic field makes it possible toquantitatively assess the main factors that control formation and destructionof the magnetospheric magnetic barrier, such as the field line draping andthe field intensity increase from the bow shock to the magnetopause, as wellas their dependence on the orientation of the interplanetary magnetic field(IMF). The Dungey cycle has been revised to take into account the essentiallytime-dependent effects of magnetic reconnection. It is shown by means ofthe Stokes’ theorem that a powerful electric field with an effective potentialdifference of several tens of kV is generated around the developing substormcurrent system. The emerging Birkeland current loop is an important particleacceleration element in the magnetosphere, contributing to the energizationof ring current protons and electrons. The electric field that arises in thedipolarization zone magnifies the already existing ring current, and the closureof its amplified part through the ionosphere generates the Region 2 fieldalignedcurrents. The motion of the expanding partial ring current around the magnetosphere, combined with the particle drift, transfers the magnetic flux from the night side of the magnetosphere to the dayside. At the dayside magnetopause, the reconnection is also responsible for the creation of theBirkeland loop, but now the electric field in the loop area decelerates the ringcurrent particles, and regions of weakened ring current are formed. Closure ofthese weakened loop currents results in a transfer of the magnetic flux from thedayside to the night side, thus ensuring its overall balance and completing theDungey cycle.

AB - The Dungey cycle is considered from the formation of a magnetic barrier andnecessary for dayside reconnection conditions till the electric field generationaround the Birkeland current loop and magnetic flux circulation balance. Data based modeling of the magnetosheath magnetic field makes it possible toquantitatively assess the main factors that control formation and destructionof the magnetospheric magnetic barrier, such as the field line draping andthe field intensity increase from the bow shock to the magnetopause, as wellas their dependence on the orientation of the interplanetary magnetic field(IMF). The Dungey cycle has been revised to take into account the essentiallytime-dependent effects of magnetic reconnection. It is shown by means ofthe Stokes’ theorem that a powerful electric field with an effective potentialdifference of several tens of kV is generated around the developing substormcurrent system. The emerging Birkeland current loop is an important particleacceleration element in the magnetosphere, contributing to the energizationof ring current protons and electrons. The electric field that arises in thedipolarization zone magnifies the already existing ring current, and the closureof its amplified part through the ionosphere generates the Region 2 fieldalignedcurrents. The motion of the expanding partial ring current around the magnetosphere, combined with the particle drift, transfers the magnetic flux from the night side of the magnetosphere to the dayside. At the dayside magnetopause, the reconnection is also responsible for the creation of theBirkeland loop, but now the electric field in the loop area decelerates the ringcurrent particles, and regions of weakened ring current are formed. Closure ofthese weakened loop currents results in a transfer of the magnetic flux from thedayside to the night side, thus ensuring its overall balance and completing theDungey cycle.

KW - магнитосфера, солнечный ветер

KW - геомагнитное поле

KW - геомагнитное поле, солнечный ветер, суббури, моделирование

KW - magnetospheric dynamics

KW - magnetosheath

KW - electric field

KW - reconnection

KW - ring current

U2 - 10.3389/fspas.2024.1494150

DO - 10.3389/fspas.2024.1494150

M3 - Article

VL - 11

JO - Frontiers in Astronomy and Space Sciences

JF - Frontiers in Astronomy and Space Sciences

SN - 2296-987X

ER -