B2 Thickness Parameter Response to Equinoctial Geomagnetic Storms

The thickness parameters that most empirical models use are generally defined by empirical relations related to ionogram characteristics. This is the case with the NeQuick model that uses an inflection point below the F2 layer peak to define a thickness parameter of the F2 bottomside of the electron density profile, which is named B2. This study is focused on the effects of geomagnetic storms on the thickness parameter B2. We selected three equinoctial storms, namely 17 March 2013, 2 October 2013 and 17 March 2015. To investigate the behavior of the B2 parameter before, during and after those events, we have analyzed variations of GNSS derived vertical TEC (VTEC) and maximum electron density (NmF2) obtained from manually scaled ionograms over 20 stations at middle and low latitudes of Asian, Euro-African and American longitude sectors. The results show two main kinds of responses after the onset of the geomagnetic events: a peak of B2 parameter prior to the increase in VTEC and NmF2 (in ~60% of the cases) and a fluctuation in B2 associated with a decrease in VTEC and NmF2 (~25% of the cases). The behavior observed has been related to the dominant factor acting after the CME shocks associated with positive and negative storm effects. Investigation into the time delay of the different measurements according to location showed that B2 reacts before NmF2 and VTEC after the onset of the storms in all the cases. The sensitivity shown by B2 during the studied storms might indicate that experimentally derived thickness parameter B2 could be incorporated into the empirical models such as NeQuick in order to adapt them to storm situations that represent extreme cases of ionospheric weather-like conditions.

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Electron density profile analysis at low latitudes

Advances in Space Research ◽

10.1016/0273-1177(88)90211-6 ◽

1988 ◽

Vol 8 (4) ◽

pp. 79-82 ◽

Cited By ~ 2

Author(s):

S.M. Radicella ◽

M.Mosert de González

Keyword(s):

Electron Density ◽

Density Profile ◽

Profile Analysis ◽

Electron Density Profile ◽

Low Latitudes

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An improved empirical formulation of an ionosphere bottomside electron density profile thickness parameter

Advances in Space Research ◽

10.1016/j.asr.2017.06.030 ◽

2017 ◽

Vol 60 (8) ◽

pp. 1725-1731 ◽

Cited By ~ 6

Author(s):

K. Alazo-Cuartas ◽

S.M. Radicella

Keyword(s):

Electron Density ◽

Density Profile ◽

Electron Density Profile ◽

Thickness Parameter

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Relationships between electron density, height and sub-peak ionospheric thickness in the night equatorial ionosphere

Annales Geophysicae ◽

10.5194/angeo-24-1343-2006 ◽

2006 ◽

Vol 24 (5) ◽

pp. 1343-1353 ◽

Cited By ~ 11

Author(s):

K. J. W. Lynn ◽

T. J. Harris ◽

M. Sjarifudin

Keyword(s):

Electron Density ◽

Equatorial Ionosphere ◽

Electron Density Profile ◽

Northern Australia ◽

Ionospheric Storm ◽

Equatorial Anomaly ◽

Night Time ◽

Slab Width ◽

Maximum Electron Density ◽

Made In

Abstract. The development and decay of the southern equatorial anomaly night-time peak in electron density as seen at a number of ionosonde reflection points extending from New Guinea and Indonesia into northern Australia was examined in terms of the characteristic rise and fall in height associated with the sunset ionisation-drift vortex at the magnetic equator. The observations relate to measurements made in November 1997. Following sunset, the ionospheric profile was observed to narrow as the maximum electron density increased during a fall in height that took the peak of the layer at Vanimo and Sumedang down to some 240 km. The fall was followed by a strong rise in which the electron density sub-peak profile expanded from a slab width (as given by POLAN) of 20 km to over 100km with no corresponding change in peak electron density. The post-sunset equatorial fall in height and associated changes in profile density and thickness continued to be seen with diminishing amplitude and increasing local time delay in moving from the anomaly peak at Vanimo to the southernmost site of observation at Townsville. Secondary events on a lesser scale sometimes occurred later in the night and may provide evidence of the multiple vortices suggested by Kudeki and Bhattacharyya (1999). Doppler measurements of vertical velocity as seen at Sumedang in Java are compared with the observed changes in electron density profile in the post-sunset period. The normal post-sunset variation in ionospheric parameters was disrupted on the night of 7 November, the night before a negative ionospheric storm was observed.

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Some theoretical of ionospheric storms at middle latitudes

Annals of Geophysics ◽

10.4401/ag-3798 ◽

1998 ◽

Vol 41 (4) ◽

Author(s):

G. A. Mansilla ◽

J. R. Manzano

Keyword(s):

Numerical Method ◽

Electron Density ◽

Geomagnetic Storm ◽

Continuity Equation ◽

Geomagnetic Storms ◽

Neutral Wind ◽

Wind Effects ◽

Middle Latitudes ◽

Maximum Electron Density ◽

Density Values

Neutral wind effects in the F2-region during geomagnetic storms are theoretically studied solving the continuity equation (with production and loss of electrons) by means of a numerical method. This study was made for storms with sudden commencement at different times of day and at different latitudes. The results show that the equatorward movements of neutral air produce either enhanced or depressed maximum electron density values which depend on the velocity of these winds when the perturbation occurs at diurnal hours. If the geomagnetic storm is present during the night, only enhanced values are observed.

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Study of Total Electron Content and Electron Density Profile from Satellite Observations During Geomagnetic Storms

Journal of Nepal Physical Society ◽

10.3126/jnphyssoc.v5i1.26932 ◽

2019 ◽

Vol 5 (1) ◽

pp. 59-66

Author(s):

B. B. Rana ◽

N. P. Chapagain ◽

B. Adhikari ◽

D. Pandit ◽

K. Pudasainee ◽

...

Keyword(s):

Solar Wind ◽

Electron Density ◽

Total Electron Content ◽

Density Profile ◽

Geomagnetic Storms ◽

Electron Density Profile ◽

Wind Pressure ◽

Electron Content ◽

Total Electron ◽

Geomagnetic Indices

Total Electron Content (TEC) and electron density profile are the key parameters in the mitigation of ionospheric effects on radio wave communication system. In this study, the variations of TEC and electron density profile have been analyzed using satellite data from four different latitude-longitude sectors (13°N -17°N, 88°E - 98°E), (30°N - 50°N, 95°W - 120°W), (26°S - 29°S, 163°W - 167°W,) and (45°S - 60°S, 105°W-120°W) during different geomagnetic storms. The interplanetary magnetic field (Bz), solar wind velocity (Vsw), solar wind pressure (Psw) and geomagnetic indices, aurora index -AE, Kp and disturbed stormed time index (Dst) are also analyzed to distinguish their effects on TEC and electron density. The geomagnetic indices and solar wind parameters are correlated with the TEC and electron density. The study showed that the value of TEC and electron density vary significantly with different latitude, longitude, altitude and solar activities. The result also concludes that the electron density profile increases with the altitude, acquired peak value around 250km-300km and decreased beyond the altitude of 300 km.

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Reconstruction of F2 layer peak electron density based on operational vertical total electron content maps

Annales Geophysicae ◽

10.5194/angeo-31-1241-2013 ◽

2013 ◽

Vol 31 (7) ◽

pp. 1241-1249 ◽

Cited By ~ 8

Author(s):

T. Gerzen ◽

N. Jakowski ◽

V. Wilken ◽

M. M. Hoque

Keyword(s):

Electron Density ◽

Total Electron Content ◽

Slab Thickness ◽

Electron Content ◽

Vertical Total Electron Content ◽

Radio Communication ◽

Total Electron ◽

Current State ◽

Maximum Electron Density ◽

Layer Peak

Abstract. Electron density is the major determining parameter of the ionosphere. Especially the maximum electron density of the F2 layer in the ionosphere, NmF2, is of particular interest with regard to the HF radio communication applications as well as for characterizing the ionosphere. In this paper we present a new method to generate global maps of NmF2. The main principle behind this approach is to use the information about the current state of the ionosphere included in global total electron content (TEC) maps as well as the relationship between total electron content, equivalent slab thickness and F2 layer peak density. Modeling of slab thickness is an interim step in our reconstruction approach. Thus, results showing the diurnal and seasonal variations and effects of solar activity on the modeled slab thickness values are given. In addition a comparison of the reconstructed NmF2 maps with measurements from several ionosonde stations as well as with the global NmF2 model NPDM is presented. Since 2011 the described method has been used at DLR Neustrelitz to generate NmF2 maps as operational service. These maps are freely available via the Space Weather Application Center Ionosphere SWACI (http://swaciweb.dlr.de).

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Estimation of the electron density profile in the D region from rocket measurement of VLF signals from a ground based transmitter

Electrical Engineering in Japan ◽

10.1002/ecja.4400641110 ◽

1981 ◽

Vol 64 (11) ◽

pp. 68-74

Author(s):

Isamu Nagano ◽

Masayoshi Mambo ◽

Tetsuo Fukami ◽

Koji Namba ◽

Iwane Kimura

Keyword(s):

Electron Density ◽

Density Profile ◽

Electron Density Profile ◽

Rocket Measurement ◽

D Region

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Radial density profile and stability of capillary discharge plasma waveguides of lengths up to 40 cm

High Power Laser Science and Engineering ◽

10.1017/hpl.2021.6 ◽

2021 ◽

Vol 9 ◽

Author(s):

M. Turner ◽

A. J. Gonsalves ◽

S. S. Bulanov ◽

C. Benedetti ◽

N. A. Bobrova ◽

...

Keyword(s):

Laser Pulse ◽

Electron Density ◽

Density Profile ◽

Pulse Propagation ◽

Spot Size ◽

Capillary Discharge ◽

Electron Density Profile ◽

Plasma Waveguide ◽

Wakefield Acceleration ◽

Plasma Wakefield

Abstract We measured the parameter reproducibility and radial electron density profile of capillary discharge waveguides with diameters of 650 $\mathrm{\mu} \mathrm{m}$ to 2 mm and lengths of 9 to 40 cm. To the best of the authors’ knowledge, 40 cm is the longest discharge capillary plasma waveguide to date. This length is important for $\ge$ 10 GeV electron energy gain in a single laser-driven plasma wakefield acceleration stage. Evaluation of waveguide parameter variations showed that their focusing strength was stable and reproducible to $<0.2$ % and their average on-axis plasma electron density to $<1$ %. These variations explain only a small fraction of laser-driven plasma wakefield acceleration electron bunch variations observed in experiments to date. Measurements of laser pulse centroid oscillations revealed that the radial channel profile rises faster than parabolic and is in excellent agreement with magnetohydrodynamic simulation results. We show that the effects of non-parabolic contributions on Gaussian pulse propagation were negligible when the pulse was approximately matched to the channel. However, they affected pulse propagation for a non-matched configuration in which the waveguide was used as a plasma telescope to change the focused laser pulse spot size.

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