Plasmaspheric response to the geomagnetic storm period March 20–23, 1990, observed by the ACTIVNY (MAGION-2) satellite

1992 ◽  
Vol 70 (7) ◽  
pp. 569-574 ◽  
Author(s):  
M. Förster ◽  
N. Jakowski ◽  
A. Best ◽  
J. Smilauer
Keyword(s):  
Magnetic Storm ◽  
Electron Density ◽  
Geomagnetic Storm ◽  
Joule Heating ◽  
Growth Phase ◽  
Langmuir Probe ◽  
Atomic Oxygen ◽  
Scale Height ◽  
Ionospheric Response ◽  
Increased Pressure

Langmuir probe data obtained during the storm period March 20–23, 1990, on board the MAGION-2 subsatellite of the ACTIVNY experiment are analyzed to study the plasmaspheric and ionospheric response to a magnetic storm. The data indicate a well-pronounced equatorward edge of the electron density trough in the afternoon (18:15 LT) at about 800 km height that moves towards lower latitudes during the course of the storm. It is interesting to note that the electron density inside the plasmasphere is increased by more than 20% in the morning shortly after sunrise (07:30 LT). This is due to enhanced O+ densities in the lower plasmasphere during the growth phase of the geomagnetic storm as measured by the ion mass spectrometer NAM-5 onboard the main satellite. It is suggested that the source for the increased density is thermospheric Joule heating at auroral latitudes with a commensurate increase in thermospheric pressure. This increased pressure causes the local thermosphere to expand both upward and equatorward. The increased atomic-oxygen scale height coupled with equatorward motion of fhermospheric perturbations results in an increased O density and resulting O+ density within the lower plasmasphere. The observations indicate a storm-induced compression of the plasmasphere that favourizes an enhanced outflow of plasma into the ionosphere leading to an increased nighttime F2-layer ionization and a depletion of the plasmasphere during the following hours.

Medium-scale wave-like irregularities of electron density and electron temperature in the upper ionosphere at subauroral and high latitudes during different phases of the magnetic storm of January 1974

1992 ◽  
Vol 70 (7) ◽  
pp. 582-594 ◽  
Author(s):  
M. Förster ◽  
M. N. Fatkullin ◽  
N. A. Gasilov ◽  
U. Schwarz
Keyword(s):  
Electron Temperature ◽  
Magnetic Storm ◽  
Electron Density ◽  
Geomagnetic Storm ◽  
Temperature Fluctuations ◽  
Magnetic Disturbance ◽  
High Latitudes ◽  
Medium Scale ◽  
Main Ionospheric Trough ◽  
Upper Ionosphere

Data obtained aboard the INTERCOSMOS-10 satellite during different phases of the geomagnetic storm in the last week of January, 1974, are used for the investigation of medium-scale wave-like irregularities of electron density and electron temperature in the upper ionosphere (altitudes from about 800 to about 1400 km) for high and subauroral latitudes. Daytime and nighttime conditions are analysed in detail. It is shown that independent of local time and of the degree of magnetic disturbance the spectra of medium-scale electron-density and electron-temperature fluctuations reveal equal characteristic wavelengths of l ≈ 130–150, 150–200, 210–240, 250–320, 340–400 km and so on. During nighttime conditions in the region of the main ionospheric trough the fluctuations of electron density (at the equatorward wall of the trough) and of electron temperature at the bottom of the trough) are separated in space. Later on it is shown that the intensity of the fluctuations of electron density and electron temperature at high and subauroral latitudes is dependent on the phase of magnetic storm.

scholarly journals Subauroral red arcs as a conjugate phenomenon: comparison of OV1-10 satellite data with numerical calculations

1997 ◽  
Vol 15 (8) ◽  
pp. 984-998 ◽  
Author(s):  
A. V. Pavlov
Keyword(s):  
Electron Density ◽  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
Atomic Oxygen ◽  
Major Ions ◽  
Integral Intensity ◽  
Rate Coefficients ◽  
Vibrationally Excited ◽  
Vibrational Distribution ◽  
Vibrational Levels

Abstract. This study compares the OV1-10 satellite measurements of the integral airglow intensities at 630 nm in the SAR arc regions observed in the northern and southern hemisphere as a conjugate phenomenon, with the model results obtained using the time-dependent one-dimensional mathematical model of the Earth ionosphere and plasmasphere (the IZMIRAN model) during the geomagnetic storm of the period 15–17 February 1967. The major enhancements to the IZMIRAN model developed in this study are the inclusion of He+ ions (three major ions: O+, H+, and He+, and three ion temperatures), the updated photochemistry and energy balance equations for ions and electrons, the diffusion of NO+ and O2+ ions and O(1D) and the revised electron cooling rates arising from their collisions with unexcited N2, O2 molecules and N2 molecules at the first vibrational level. The updated model includes the option to use the models of the Boltzmann or non-Boltzmann distributions of vibrationally excited molecular nitrogen. Deviations from the Boltzmann distribution for the first five vibrational levels of N2 were calculated. The calculated distribution is highly non-Boltzmann at vibrational levels v > 2 and leads to a decrease in the calculated electron density and integral intensity at 630 nm in the northern and southern hemispheres in comparison with the electron density and integral intensity calculated using the Boltzmann vibrational distribution of N2. It is found that the intensity at 630 nm is very sensitive to the oxygen number densities. Good agreement between the modelled and measured intensities is obtained provided that at all altitudes of the southern hemisphere a reduction of about factor 1.35 in MSIS-86 atomic oxygen densities is included in the IZMIRAN model with the non-Boltzmann vibrational distribution of N2. The effect of using of the O(1D) diffusion results in the decrease of 4–6% in the calculated integral intensity of the northern hemisphere and 7–13% in the calculated integral intensity of the southern hemisphere. It is found that the modelled intensities of the southern hemisphere are more sensitive to the assumed values of the rate coefficients of O+(4S) ions with the vibrationally excited nitrogen molecules and quenching of O+(2D) by atomic oxygen than the modelled intensities of the northern hemisphere.

scholarly journals Ionospheric response to the corotating interaction region-driven geomagnetic storm of October 2002

2009 ◽  
Vol 114 (A12) ◽  
pp. n/a-n/a ◽  
Author(s):  
D. Pokhotelov ◽  
C. N. Mitchell ◽  
P. T. Jayachandran ◽  
J. W. MacDougall ◽  
M. H. Denton
Keyword(s):  
Geomagnetic Storm ◽  
Interaction Region ◽  
Corotating Interaction Region ◽  
Ionospheric Response

scholarly journals Variations of topside ionospheric scale heights over Millstone Hill during the 30-day incoherent scatter radar experiment

2007 ◽  
Vol 25 (9) ◽  
pp. 2019-2027 ◽  
Author(s):  
L. Liu ◽  
W. Wan ◽  
M.-L. Zhang ◽  
B. Ning ◽  
S.-R. Zhang ◽  
...  
Keyword(s):  
Electron Density ◽  
Thermal Structure ◽  
Plasma Temperature ◽  
Scale Height ◽  
Incoherent Scatter Radar ◽  
Density Profiles ◽  
Incoherent Scatter ◽  
Scatter Radar ◽  
Vertical Scale ◽  
Electron Density Profiles

Abstract. A 30-day incoherent scatter radar (ISR) experiment was conducted at Millstone Hill (288.5° E, 42.6° N) from 4 October to 4 November 2002. The altitude profiles of electron density Ne, ion and electron temperature (Ti and Te), and line-of-sight velocity during this experiment were processed to deduce the topside plasma scale height Hp, vertical scale height VSH, Chapman scale height Hm, ion velocity, and the relative altitude gradient of plasma temperature (dTp/dh)/Tp, as well as the F2 layer electron density (NmF2) and height (hmF2). These data are analyzed to explore the variations of the ionosphere over Millstone Hill under geomagnetically quiet and disturbed conditions. Results show that ionospheric parameters generally follow their median behavior under geomagnetically quiet conditions, while the main feature of the scale heights, as well as other parameters, deviated significantly from their median behaviors under disturbed conditions. The enhanced variability of ionospheric scale heights during the storm-times suggests that the geomagnetic activity has a major impact on the behavior of ionospheric scale heights, as well as the shape of the topside electron density profiles. Over Millstone Hill, the diurnal behaviors of the median VSH and Hm are very similar to each other and are not so tightly correlated with that of the plasma scale height Hp or the plasma temperature. The present study confirms the sensitivity of the ionospheric scale heights over Millstone Hill to thermal structure and dynamics. The values of VSH/Hp tend to decrease as (dTp/dh)/Tp becomes larger or the dynamic processes become enhanced.

scholarly journals Diagnostics of low-pressure capacitively coupled RF discharge argon plasma

2019 ◽  
Vol 13 (27) ◽  
pp. 76-82
Author(s):  
Kadhim A. Aadim
Keyword(s):  
Electron Temperature ◽  
Electron Density ◽  
Langmuir Probe ◽  
Gas Flow ◽  
Low Pressure ◽  
Gas Pressure ◽  
Rf Discharge ◽  
Electrode Gap ◽  
Probe Characteristic ◽  
Capacitively Coupled

Low-pressure capacitively coupled RF discharge Ar plasma has been studied using Langmuir probe. The electron temperature, electron density and Debay length were calculated under different pressures and electrode gap. In this work the RF Langmuir probe is designed using 4MHz filter as compensation circuit and I-V probe characteristic have been investigated. The pressure varied from 0.07 mbar to 0.1 mbar while electrode gap varied from 2-5 cm. The plasma was generated using power supply at 4MHz frequency with power 300 W. The flowmeter is used to control Argon gas flow in the range of 600 standard cubic centimeters per minute (sccm). The electron temperature drops slowly with pressure and it's gradually decreased when expanding the electrode gap. As the gas pressure increases, the plasma density rises slightly at low gas pressure while it drops little at higher gas pressure. The electron density decreases rapidly with expand distances between electrodes.

scholarly journals Identifying possible Stratification phenomenon in ionospheric F2 Layer using the data observed by the Demeter satellite: Method and Results

2019 ◽  
Author(s):  
Xiuying Wang ◽  
Dehe Yang ◽  
Dapeng Liu ◽  
Wei Chu
Keyword(s):  
Statistical Method ◽  
Electron Density ◽  
Langmuir Probe ◽  
Geomagnetic Equator ◽  
Density Data ◽  
Demeter Satellite ◽  
Summer Hemisphere ◽  
First Time ◽  
Different Altitudes

Abstract. Many studies have revealed the stratification phenomenon of the topside ionospheric F2 layer using ground-based or satellite-based ionograms, which can show direct signs of this phenomenon. However, it is difficult to identify this phenomenon using the satellite-based in situ electron density data. Therefore, a statistical method, using the shuffle resampling skill, is adopted in this paper. For the first time, in situ electron density data, recorded by the same Langmuir probe onboard the Demeter satellite at different altitudes, are analyzed and a possible stratification phenomenon is identified using the proposed method. Our results show that the nighttime stratification, possibly a permanent phenomenon, can cover most longitudes near the geomagnetic equator, which is not found from the daytime data. The arch-like nighttime stratification decreases slowly on the summer hemisphere and thus extends a larger latitudinal distance from the geomagnetic equator. All results, obtained by the proposed method, indicate that the stratification phenomenon is more complex than what has previously been found. The proposed method thus is an effective one, which can also be used on similar studies of comparing fluctuated data.

scholarly journals Identifying a possible stratification phenomenon in ionospheric F2 layer using the data observed by the DEMETER satellite: method and results

2019 ◽  
Vol 37 (4) ◽  
pp. 645-655 ◽  
Author(s):  
Xiuying Wang ◽  
Dehe Yang ◽  
Dapeng Liu ◽  
Wei Chu
Keyword(s):  
Electron Density ◽  
Langmuir Probe ◽  
Geomagnetic Equator ◽  
Density Data ◽  
Demeter Satellite ◽  
Summer Hemisphere ◽  
Electro Magnetic ◽  
First Time ◽  
Different Altitudes

Abstract. Many studies have revealed the stratification phenomenon of the topside ionospheric F2 layer using ground-based or satellite-based ionograms, which can show direct signs of this phenomenon. However, it is difficult to identify this phenomenon using the satellite-based in situ electron density data. Therefore, a statistical method, using the shuffle resampling skill, is adopted in this paper. For the first time, in situ electron density data, recorded by the same Langmuir probe aboard the DEMETER (Detection of Electro-Magnetic Emission Transmitted from Earthquake Regions) satellite at different altitudes, are analyzed, and a possible stratification phenomenon is identified using the proposed method. Our results show that the nighttime stratification, possibly a permanent phenomenon, can cover most longitudes near the geomagnetic equator, which is not found from the daytime data. The arch-like nighttime stratification decreases slowly on the summer hemisphere and thus extends a larger latitudinal distance from the geomagnetic equator. All results, obtained by the proposed method, indicate that the stratification phenomenon is more complex than what has previously been found. The proposed method is thus an effective one, which can also be used in similar studies of comparing fluctuated data.

Low latitude ionospheric response to March 2015 geomagnetic storm using multi-instrument TEC observations over India

2020 ◽  
Vol 365 (12) ◽  
Author(s):  
A. Vishnu Vardhan ◽  
P. Babu Sree Harsha ◽  
D. Venkata Ratnam ◽  
A. K. Upadhayaya
Keyword(s):  
Geomagnetic Storm ◽  
Low Latitude ◽  
Ionospheric Response
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