Ionospheric current system associated with the equatorial counterelectrojet

1994 ◽  
Vol 99 (A7) ◽  
pp. 13209 ◽  
Author(s):  
R. G. Rastogi
Keyword(s):  
Current System ◽  
Ionospheric Current ◽  
Ionospheric Current System

scholarly journals Numerical analysis of global ionospheric current system including the effect of equatorial enhancement

1999 ◽  
Vol 17 (5) ◽  
pp. 692-706 ◽  
Author(s):  
S. Tsunomura
Keyword(s):  
Magnetic Fields ◽  
Electric Field ◽  
Current System ◽  
Equatorial Region ◽  
Iri Model ◽  
Ionospheric Layer ◽  
Ionospheric Current ◽  
New Model ◽  
Ionospheric Current System ◽  
Field Aligned Current

Abstract. A modeling method is proposed to derive a two-dimensional ionospheric layer conductivity, which is appropriate to obtain a realistic solution of the polar-originating ionospheric current system including equatorial enhancement. The model can be obtained by modifying the conventional, thin shell conductivity model. It is shown that the modification for one of the non-diagonal terms (Σθφ) in the conductivity tensor near the equatorial region is very important; the term influences the profile of the ionospheric electric field around the equator drastically. The proposed model can reproduce well the results representing the observed electric and magnetic field signatures of geomagnetic sudden commencement. The new model is applied to two factors concerning polar-originating ionospheric current systems. First, the latitudinal profile of the DP2 amplitude in the daytime is examined, changing the canceling rate for the dawn-to-dusk electric field by the region 2 field-aligned current. It is shown that the equatorial enhancement would not appear when the ratio of the total amount of the region 2 field-aligned current to that of region 1 exceeds 0.5. Second, the north-south asymmetry of the magnetic fields in the summer solstice condition of the ionospheric conductivity is examined by calculating the global ionospheric current system covering both hemispheres simultaneously. It is shown that the positive relationship between the magnitudes of high latitude magnetic fields and the conductivity is clearly seen if a voltage generator is given as the source, while the relationship is vague or even reversed for a current generator. The new model, based on the International Reference Ionosphere (IRI) model, can be applied to further investigations in the quantitative analysis of the magnetosphere-ionosphere coupling problems.Key words. Ionosphere (electric fields and currents; equatorial ionosphere; ionosphere-magnetosphere interactions)

Global Pc5 caused by aDP2-type ionospheric current system

2002 ◽  
Vol 107 (A2) ◽  
pp. SMP 8-1-SMP 8-12 ◽  
Author(s):  
T. Motoba ◽  
T. Kikuchi ◽  
H. Lühr ◽  
H. Tachihara ◽  
T.-I. Kitamura ◽  
...  
Keyword(s):  
Current System ◽  
Ionospheric Current ◽  
Ionospheric Current System

Realtime geomagnetic indices for mid-latitudes. MID-R, MID-E, MID-U and MID-L

2020 ◽  
Author(s):  
Antonio Guerrero ◽  
Elena Saiz ◽  
Consuelo Cid
Keyword(s):  
Ring Current ◽  
Current System ◽  
Physical Processes ◽  
Ionospheric Current ◽  
Disturbance Index ◽  
Geomagnetic Indices ◽  
Ionospheric Current System ◽  
Operational Space ◽  
Low Latitudes ◽  
The University

<p>Mid latitudes around 40 degree are influenced by effects typically found at both high and low latitudes. Moreover, the focus of the Solar Quiet ionospheric current system, drifts around these mid-latitudes. Consequently they have been considered as a complicated place to infer the geospace state from the ground and also complicated for practical procedures to generate geomagnetic indices. <br>The procedure designed at the University of Alcala specially focused on removing solar regular variations at mid-latitudes is delivering a geomagnetic Local Disturbance index (LDi) in realtime. The same procedure can be used to produce global geomagnetic indices when applied to several geomagnetic stations at these latitudes. <br>We present in this work the high-resolution (one minute) realtime production of ring current and auroral indices (MID-R, MID-E, MID-U and MID-L) similar to the well known Dst and AE indices for mid-latitudes which will help in the understanding of the complex physical processes that emerge at these latitudes. At the same time they fill a gap in the current operational space weather products available for these latitudes.</p>

Numerical studies on the dynamics of the ionospheric current system

1998 ◽  
Vol 22 (9) ◽  
pp. 1369-1372
Author(s):  
G.T Birk ◽  
U Becker ◽  
J Dreher ◽  
T Neukirch
Keyword(s):  
Current System ◽  
Ionospheric Current ◽  
Ionospheric Current System ◽  
Numerical Studies

scholarly journals An intense SFE and SSC event in geomagnetic <i>H</i>, <i>Y</i> and <i>Z</i> fields at the Indian chain of observatories

1997 ◽  
Vol 15 (10) ◽  
pp. 1301-1308 ◽  
Author(s):  
R. G. Rastogi ◽  
D. R. K. Rao ◽  
S. Alex ◽  
B. M. Pathan ◽  
T. S. Sastry
Keyword(s):  
Solar Flare ◽  
Geomagnetic Storm ◽  
Geomagnetic Field ◽  
Current System ◽  
Equatorial Electrojet ◽  
Start Time ◽  
Low Latitude ◽  
Ionospheric Current ◽  
Ionospheric Current System ◽  
Solar Flare Effects

Abstract. Changes in the three components of geomagnetic field are reported at the chain of ten geomagnetic observatories in India during an intense solar crochet that occurred at 1311 h 75° EMT on 15 June 1991 and the subsequent sudden commencement (SSC) of geomagnetic storm at 1518 h on 17 June 1991. The solar flare effects (SFE) registered on the magnetograms appear to be an augmentation of the ionospheric current system existing at the start time of the flare. An equatorial enhancement in ΔH due to SFE is observed to be similar in nature to the latitudinal variation of SQ (H) at low latitude. ΔY registered the largest effect at 3.6° dip latitude at the fringe region of the electrojet. ΔZ had positive amplitudes at the equatorial stations and negative at stations north of Hyderabad. The SSC amplitude in the H component is fairly constant with latitude, whereas the Z component again showed larger positive excursions at stations within the electrojet belt. These results are discussed in terms of possible currents of internal and external origin. The changes in the Y field strongly support the idea that meridional current at an equatorial electrojet station flows in the ionospheric dynamo, E.

scholarly journals Ionospheric current system during sudden stratospheric warming events

2012 ◽  
Vol 117 (A3) ◽  
pp. n/a-n/a ◽  
Author(s):  
Y. Yamazaki ◽  
K. Yumoto ◽  
D. McNamara ◽  
T. Hirooka ◽  
T. Uozumi ◽  
...  
Keyword(s):  
Current System ◽  
Stratospheric Warming ◽  
Sudden Stratospheric Warming ◽  
Ionospheric Current ◽  
Ionospheric Current System
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