scholarly journals Effects of Geomagnetic Storms on the Postsunset Vertical Plasma Drift in the Equatorial Ionosphere

2018 ◽  
Vol 123 (5) ◽  
pp. 4181-4191 ◽  
Author(s):  
Chao-Song Huang
Keyword(s):  
Geomagnetic Storms ◽  
Equatorial Ionosphere ◽  
Plasma Drift

scholarly journals Observations of GPS ionospheric scintillations over Wuhan during geomagnetic storms

2006 ◽  
Vol 24 (6) ◽  
pp. 1581-1590 ◽  
Author(s):  
G. Li ◽  
B. Ning ◽  
W. Wan ◽  
B. Zhao
Keyword(s):  
Geomagnetic Storms ◽  
Equatorial Ionosphere ◽  
The Other ◽  
Small Scale ◽  
Plasma Drift ◽  
Equatorial Ionization Anomaly ◽  
Spread F ◽  
Ionospheric Scintillations ◽  
Sporadic E Layer ◽  
Sporadic E

Abstract. During the two geomagnetic storms which occurred on 1 October 2002 and 22 January 2004, the strong ionospheric scintillations of the GPS L1 band were observed at Wuhan station (30.6° N, 114.4° E, 45.8° Dip), which is situated near the northern crest of the equatorial ionosphere anomaly. We found that the intense scintillations were associated with the main phases of the storms and were co-located with the enhancement of the equatorial ionization anomaly (EIA); the co-existence of large- and small-scale irregularities at post-midnight was also found. The results may be relevant regarding the influence of the equatorial ionospheric eastward electric field during geomagnetic storms. On the other hand, GPS L1 band scintillations were not observed during the other two similar storms on 16 July 2003 and 20 November 2003. One of the reasons is probably that the sporadic E layer observed at the storms inhibited the generation of spread F by changing the Pedersen conductivity and suppressing the upward plasma drift.

F-region nocturnal zonal plasma drift velocities of the brazilian equatorial ionosphere during maximum solar

2005 ◽  
Author(s):  
Daniela Cristina Santana Arruda ◽  
José Humberto Andrade Sobral ◽  
Mangalathayil Ali Abdu ◽  
Vivian Moreira de Castilho and Ricardo Arlen Buriti
Keyword(s):  
Equatorial Ionosphere ◽  
Plasma Drift ◽  
F Region

scholarly journals Role of the magnetospheric and ionospheric currents in the generation of the equatorial scintillations during geomagnetic storms

2004 ◽  
Vol 22 (9) ◽  
pp. 3195-3202 ◽  
Author(s):  
L. Z. Biktash
Keyword(s):  
Solar Wind ◽  
Electric Fields ◽  
Ring Current ◽  
Geomagnetic Storms ◽  
Equatorial Ionosphere ◽  
Experimental Investigations ◽  
Polar Regions ◽  
Ionospheric Currents ◽  
Geomagnetic Variations ◽  
Activity Effect

Abstract. The equatorial ionosphere parameters, Kp, Dst, AU and AL indices characterized contribution of different magnetospheric and ionospheric currents to the H-component of geomagnetic field are examined to test the geomagnetic activity effect on the generation of ionospheric irregularities producing VLF scintillations. According to the results of the current statistical studies, one can predict near 70% of scintillations from Aarons' criteria using the Dst index, which mainly depicts the magnetospheric ring current field. To amplify Aarons' criteria or to propose new criteria for predicting scintillation characteristics is the question. In the present phase of the experimental investigations of electron density irregularities in the ionosphere new ways are opened up because observations in the interaction between the solar wind - magnetosphere - ionosphere during magnetic storms have progressed greatly. According to present view, the intensity of the electric fields and currents at the polar regions, as well as the magnetospheric ring current intensity, are strongly dependent on the variations of the interplanetary magnetic field. The magnetospheric ring current cannot directly penetrate the equatorial ionosphere and because of this difficulties emerge in explaining its relation to scintillation activity. On the other hand, the equatorial scintillations can be observed in the absence of the magnetospheric ring current. It is shown that in addition to Aarons' criteria for the prediction of the ionospheric scintillations, models can be used to explain the relationship between the equatorial ionospheric parameters, h'F, foF2, and the equatorial geomagnetic variations with the polar ionosphere currents and the solar wind.

Local time dependant response of Indian equatorial ionosphere to the moderate geomagnetic storms

2007 ◽  
Vol 39 (8) ◽  
pp. 1304-1312 ◽  
Author(s):  
S. Tulasi Ram ◽  
P.V.S. Rama Rao ◽  
D.S.V.V.D. Prasad ◽  
K. Niranjan ◽  
R. Sridharan ◽  
...  
Keyword(s):  
Local Time ◽  
Geomagnetic Storms ◽  
Equatorial Ionosphere

Ionospheric dynamic and coupling processes during geomagnetic storms

2020 ◽  
Author(s):  
Chaosong Huang
Keyword(s):  
Electric Fields ◽  
Geomagnetic Storms ◽  
Equatorial Ionosphere ◽  
Ion Composition ◽  
Hemispheric Differences ◽  
Ion Density ◽  
Ion Drift ◽  
Low Latitudes ◽  
Coupling Processes ◽  
Ionospheric Dynamics

<p>Geomagnetic storms cause the largest disturbances in the ionosphere-thermosphere system. We use measurements with satellites and ground based radars to study storm-induced variations in ionospheric plasma drift, ion density, and ion composition at low latitudes. It is found that the storm-time change of ion drift velocity in the equatorial ionosphere can reach 200-300 m/s, the change of ion density can be one or two orders of magnitude, and the change of ion composition can be 50-80%. These extremely large changes in the ionosphere can last for several hours or even a few days during the main and recovery phases of magnetic storms. The longitudinal, latitudinal and hemispheric differences of storm-time ionospheric disturbances are analyzed from measurements of multiple satellites or radar chain. Very long, continuous penetration of interplanetary electric fields to the equatorial ionosphere for 6 or even 14 hours are observed, and the time when disturbance dynamo electric fields become dominant is identified. The interplay of penetration, shielding, and disturbance dynamo electric fields in the storm-time ionosphere will be addressed. Mechanisms responsible for storm-time ionospheric dynamics will be discussed.</p>

scholarly journals Letter to the editor: Electric field fluctuations (25-35 min) in the midnight dip equatorial ionosphere

2000 ◽  
Vol 18 (2) ◽  
pp. 252-256 ◽  
Author(s):  
J. Hanumath Sastri ◽  
H. Luhr ◽  
H. Tachihara ◽  
T. -I. Kitamura ◽  
J. V. S. V. Rao
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Geomagnetic Latitude ◽  
Equatorial Ionosphere ◽  
Plasma Drift ◽  
F Region ◽  
Vertical Drift ◽  
Field Fluctuations ◽  
Dip Equator ◽  
Electric Fields And Currents

Abstract. Measurements with a HF Doppler sounder at Kodaikanal (10.2°N, 77.5°E, geomagnetic latitude 0.8°N) showed conspicuous quasi-periodic fluctuations (period 25-35 min) in F region vertical plasma drift, Vz in the interval 0047-0210 IST on the night of 23/24 December, 1991 (Ap = 14, Kp < 4-). The fluctuations in F region vertical drift are found to be coherent with variations in Bz (north-south) component of interplanetary magnetic field (IMF), in geomagnetic H/X components at high-mid latitude locations both in the sunlit and dark hemispheres and near the dayside dip equator, suggestive of DP2 origin. But the polarity of the electric field fluctuations at the midnight dip equator (eastward) is the same as the dayside equator inferred from magnetic variations, contrary to what is expected of equatorial DP2. The origin of the coherent occurrence of equatorial electric field fluctuations in the DP2 range of the same sign in the day and night hemispheres is unclear and merits further investigations.Key words: Ionosphere (electric fields and currents; equatorial ionosphere; ionosphere-magnetosphere interactions)

The solar wind control of the equatorial ionosphere dynamics during geomagnetic storms

2008 ◽  
Vol 41 (4) ◽  
pp. 562-568 ◽  
Author(s):  
L.Z. Biktash ◽  
T. Maruyama ◽  
K. Nozaki
Keyword(s):  
Solar Wind ◽  
Geomagnetic Storms ◽  
Equatorial Ionosphere
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