On Transient Penetration of the Convection Electric Field to Low Latitudes During the Substorm Expansion Phase

The influence of geomagnetic storms on the ionosphere in the equatorial and low latitudes can be either rising or falling value of the value foF2 with the different response delay time. The difference in response is one of them allegedly influenced by the modification of Equatorial Electrojet (EEJ) generated by the penetration of high latitude electric field towards the low latitude electric field and the equator. Therefore, this paper analyzes the influence of the high latitude penetration of electric current to the low latitude electric current towards the ionosphere response to Indonesia's current geomagnetic storms using the data foF2 BPAA Sumedang (SMD; 6,910 S; 106,830E geographic coordinates or 16,550 S; 179,950 E magnetic coordinates) and data from the Biak geomagnetic field station (BIK; 1,080 S; 136,050 E geographic coordinates or 9,730 S; 207,390 E magnetic coordinates) in 2000-2001. The result showed that the injection of the electric field of the high latitudes to lower latitudes causing foF2 BPAA Sumedang to be disturbed. Onset of the foF2 disturbance in BPAA Sumedang started coincide with EEJ(HBIK-HDRW) and reached its minimum point with a time delay between 0 to 4 hours before and after Dst index reached the minimum point. For a delay time of 0 to 4 hours after the Dst index reached the minimum point, the results were in accordance with the research results from the prior research. However, for the time difference of between 0 to 4 hours before the Dst index reached the minimum point, the results differ from their results. AbstrakPengaruh badai geomagnet terhadap ionosfer di ekuator dan lintang rendah berupa naiknya nilai foF2 atau turunnya nilai foF2 dengan waktu tunda respon berbeda-beda. Perbedaan respon tersebut salah satunya diduga dipengaruhi oleh modifikasi Equatorial electrojet (EEJ) yang dihasilkan oleh penetrasi medan listrik lintang tinggi sampai daerah lintang rendah dan ekuator. Oleh karena itu, dalam makalah ini dilakukan analisis pengaruh penetrasi arus listrik lintang tinggi ke lintang rendah terhadap ionosfer saat badai geomagnet menggunakan data foF2 dari Balai Pengamatan Antariksa dan Atmosfer (BPAA) Sumedang (SMD; 6,910 LS; 106,830 BT koordinat geografis atau 16,550 LS; 179,950 BT koordinat magnet) dan data medan geomagnet dari stasiun Biak (BIK; 1,080 LS; 136,050 BT koordinat geografis atau 9,730 LS; 207,390 BT koordinat magnet) tahun 2000-2001. Hasilnya diperoleh bahwa penetrasi medan listrik dari lintang tinggi ke lintang lebih rendah Indonesia menyebabkan foF2 BPAA Sumedang terganggu. Onset gangguan foF2 BPAA Sumedang mulai terjadi bertepatan dengan EEJ(HBIK-HDRW) mencapai titik minimumnya dengan jeda waktu antara 0 sampai 4 jam sebelum dan sesudah indeks Dst mencapai minimum. Untuk beda waktu 0 sampai 4 jam sesudah indeks Dst mencapai minimum, hasilnya bersesuaian dengan hasil penelitian peneliti sebelumnya. Namun, untuk beda waktu 0 sampai 4 jam sebelum indeks Dst mencapai minimum, hasilnya merupakan temuan berbeda dari hasil mereka.

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Magnetospheric convection electric field dynamics andstormtime particle energization: case study of the magneticstorm of 4 May 1998

Annales Geophysicae ◽

10.5194/angeo-22-497-2004 ◽

2004 ◽

Vol 22 (2) ◽

pp. 497-510 ◽

Cited By ~ 29

Author(s):

G. V. Khazanov ◽

M. W. Liemohn ◽

T. S. Newman ◽

M.-C. Fok ◽

A. J. Ridley

Keyword(s):

Electric Field ◽

Electric Fields ◽

Transport Model ◽

Storm Event ◽

Inner Magnetosphere ◽

Narrow Channels ◽

Near Earth Space ◽

Magnetospheric Convection ◽

Convection Electric Field ◽

Seed Population

Abstract. It is shown that narrow channels of high electric field are an effective mechanism for injecting plasma into the inner magnetosphere. Analytical expressions for the electric field cannot produce these channels of intense plasma flow, and thus, result in less entry and adiabatic energization of the plasma sheet into near-Earth space. For the ions, omission of these channels leads to an underprediction of the strength of the stormtime ring current and therefore, an underestimation of the geoeffectiveness of the storm event. For the electrons, omission of these channels leads to the inability to create a seed population of 10-100 keV electrons deep in the inner magnetosphere. These electrons can eventually be accelerated into MeV radiation belt particles. To examine this, the 1-7 May 1998 magnetic storm is studied with a plasma transport model by using three different convection electric field models: Volland-Stern, Weimer, and AMIE. It is found that the AMIE model can produce particle fluxes that are several orders of magnitude higher in the L = 2 – 4 range of the inner magnetosphere, even for a similar total cross-tail potential difference. Key words. Space plasma physics (charged particle motion and acceleration) – Magnetospheric physics (electric fields, storms and substorms)

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Effect of the large-scale convection electric field structure on the formation of thin ionization layers at high latitudes

Journal of Atmospheric and Terrestrial Physics ◽

10.1016/0021-9169(94)90221-6 ◽

1994 ◽

Vol 56 (3) ◽

pp. 401-415 ◽

Cited By ~ 10

Author(s):

W.A. Bristow ◽

B.J. Watkins

Keyword(s):

Electric Field ◽

Large Scale ◽

Field Structure ◽

High Latitudes ◽

Convection Electric Field

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Energetic ion injection and formation of the storm-time symmetric ring current

Annales Geophysicae ◽

10.5194/angeo-24-3547-2006 ◽

2006 ◽

Vol 24 (12) ◽

pp. 3547-3556 ◽

Cited By ~ 8

Author(s):

L. Xie ◽

Z. Y. Pu ◽

X. Z. Zhou ◽

S. Y. Fu ◽

Q.-G. Zong ◽

...

Keyword(s):

Electric Field ◽

Ring Current ◽

Particle Trajectory ◽

Three Dimensional ◽

Extensive Study ◽

Current Injection ◽

Ion Injection ◽

Convection Electric Field ◽

Trajectory Calculations ◽

Current Region

Abstract. An extensive study of ring current injection and intensification of the storm-time ring current is conducted with three-dimensional (3-D) test particle trajectory calculations (TPTCs). The TPTCs reveal more accurately the process of ring current injection, with the main results being the following: (1) an intense convection electric field can effectively energize and inject plasma sheet particles into the ring current region within 1–3 h. (2) Injected ions often follow chaotic trajectories in non-adiabatic regions, which may have implications in storm and ring current physics. (3) The shielding electric field, which arises as a consequence of enhanced convection and co-exists with the injection and convection electric field, may cause the original open trajectories of injected ions with higher energy to change into closed ones, thus playing a role in the formation of the symmetric ring current.

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Measurements of convection electric field in the inner magnetosphere

Science China Technological Sciences ◽

10.1007/s11431-017-9200-6 ◽

2018 ◽

Vol 61 (12) ◽

pp. 1866-1871

Author(s):

Xin Lv ◽

WenLong Liu

Keyword(s):

Electric Field ◽

Inner Magnetosphere ◽

Convection Electric Field

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Ring current ion flows and convection electric field as expected from observations by SAC-B/ISENA

Geophysical Research Letters ◽

10.1029/96gl02925 ◽

1996 ◽

Vol 23 (23) ◽

pp. 3285-3288 ◽

Cited By ~ 12

Author(s):

A. Milillo ◽

S. Orsini ◽

I. A. Daglis ◽

M. Candidi

Keyword(s):

Electric Field ◽

Ring Current ◽

Convection Electric Field

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The relationship between the magnetosphere and magnetospheric/auroral substorms

Annales Geophysicae ◽

10.5194/angeo-31-387-2013 ◽

2013 ◽

Vol 31 (3) ◽

pp. 387-394 ◽

Cited By ~ 13

Author(s):

S.-I. Akasofu

Keyword(s):

Electric Field ◽

Growth Phase ◽

Magnetic Energy ◽

Dissipative System ◽

Satellite Observation ◽

Recovery Phase ◽

Release Process ◽

Expansion Phase ◽

Auroral Substorms ◽

The Relationship

Abstract. On the basis of auroral and polar magnetic substorm studies, the relationship between the solar wind-magnetosphere dynamo (the DD dynamo) current and the substorm dynamo (the UL dynamo) current is studied. The characteristics of both the DD and UL currents reveal why auroral substorms consist of the three distinct phases after the input power ε is increased above 1018 erg s−1. (a) The growth phase; the magnetosphere can accumulate magnetic energy for auroral substorms, when the ionosphere cannot dissipate the power before the expansion phase. (b) The expansion phase; the magnetosphere releases the accumulated magnetic energy during the growth phase in a pulse-like manner in a few hours, because it tries to stabilize itself when the accumulated energy reaches to about 1023 erg s−1. (c) The recovery phase; the magnetosphere becomes an ordinary dissipative system after the expansion phase, because the ionosphere becomes capable of dissipating the power with the rate of 1018 ~ 1019 erg s−1. On the basis of the above conclusion, it is suggested that the magnetosphere accomplishes the pulse-like release process (resulting in spectacular auroral activities) by producing plasma instabilities in the current sheet, thus reducing the current. The resulting contraction of the magnetic field lines (expending the accumulated magnetic energy), together with break down of the "frozen-in" field condition at distances of less than 10 RE, establishes the substorm dynamo that generates an earthward electric field (Lui and Kamide, 2003; Akasofu, 2011). It is this electric field which manifests as the expansion phase. A recent satellite observation at a distance of as close as 8.1 RE by Lui (2011) seems to support strongly the occurrence of the chain of processes suggested in the above. It is hoped that although the concept presented here is very crude, it will serve in providing one way of studying the three phases of auroral substorms. In turn, a better understanding of auroral substorms will also be useful in studying the magnetosphere, because various auroral activities can be the visible guide for this endeavor.

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