Measurements of the total electron content and the equivalent slab thickness of the midlatitude ionosphere

The generation and propagation of ionospheric storms are studied by analyzing EISCAT radar, and vertical-sounding and total-electron-content data obtained under different geophysical conditions. Both, case studies as well as the average storm pattern of percentage deviations of different ionospheric parameters from their corresponding reference values such as total electron content, F2-layer critical frequency foF2, F2-layer height hmF2, and slab thickness τ indicate the action of a perturbation electric field during the first few hours during the onset phase of geomagnetic storms. Considering the onset phase of the storm on July 28–29, 1987 evidence has been found that high-latitude electric fields may penetrate to lower latitudes before the ring current has developed. In most cases this process is accompanied by a positive phase in the upper ionosphere and F2-layer ionization. Different mechanisms are assumed to be responsible for the daytime and nighttime behaviour, respectively. The negative phase propagates equatorward with velocities in the order of 70–350 m s−1 following a strong heating of the thermosphere and ionosphere due to the auroral electrojet.

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Statistical analysis of ionospheric total electron content (TEC): long-term estimation of extreme TEC in Japan

Earth Planets and Space ◽

10.1186/s40623-021-01374-8 ◽

2021 ◽

Vol 73 (1) ◽

Author(s):

Michi Nishioka ◽

Susumu Saito ◽

Chihiro Tao ◽

Daikou Shiota ◽

Takuya Tsugawa ◽

...

Keyword(s):

Total Electron Content ◽

Communication Systems ◽

Extreme Values ◽

Cumulative Distribution ◽

Propagation Path ◽

Slab Thickness ◽

Electron Content ◽

Data Set ◽

Total Electron ◽

Ionospheric Total Electron Content

AbstractIonospheric total electron content (TEC) is one of the key parameters for users of radio-based systems, such as the Global Navigation Satellite System, high-frequency communication systems, and space-based remote sensing systems, since total ionospheric delay is proportional to TEC through the propagation path. It is important to know extreme TEC values in readiness for hazardous ionospheric conditions. The purpose of this study is to estimate extreme TEC values with occurrences of once per year, 10 years, and hundred years in Japan. In order to estimate the extreme values of TEC, a cumulative distribution function of daily TEC is derived using 22 years of TEC data from 1997 to 2018. The extreme values corresponding to once per year and 10 years are 90 and 110 TECU, respectively, in Tokyo, Japan. On the other hand, the 22-year data set is not sufficient to estimate the once-per-100-year value. Thus, we use the 62-year data set of manually scaled ionosonde data for the critical frequency of the F-layer (foF2) at Kokubunji in Tokyo. First, we study the relationship between TEC and foF2 for 22 years and investigate the slab thickness. Then the result is applied to the statistical distribution of foF2 data for 62 years. In this study, two methods are applied to estimate the extreme TEC value. In the first method, the distribution of slab thickness is artificially inflated to estimate extreme TEC values. In the second method, extreme slab thicknesses are applied to estimate extreme TEC values. The result shows that the once-per-100-year TEC is about 150–190 TECU at Tokyo. The value is also estimated to be 180–230 TECU in Kagoshima and 120–150 TECU in Hokkaido, in the southern and northern parts of Japan, respectively.

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Statistical Analysis of Ionospheric Total Electron Content (TEC): Long-Term Estimation of Extreme TEC in Japan

10.21203/rs.3.rs-41992/v1 ◽

2020 ◽

Author(s):

Michi Nishioka ◽

Susumu Saito ◽

Chihiro Tao ◽

Daikou Shiota ◽

Takuya Tsugawa ◽

...

Keyword(s):

Total Electron Content ◽

Communication Systems ◽

Extreme Values ◽

Cumulative Distribution ◽

Propagation Path ◽

Slab Thickness ◽

Electron Content ◽

Data Set ◽

Total Electron ◽

Ionospheric Total Electron Content

Abstract Ionospheric total electron content (TEC) is one of the key parameters for users of radio-based systems, such as the Global Navigation Satellite System, high-frequency communication systems, and space-based remote sensing systems, since total ionospheric delay is proportional to TEC through the propagation path. It is important to know extreme TEC values in readiness for hazardous ionospheric conditions. The purpose of this study is to estimate extreme TEC values with occurrences of once per year, ten years, and hundred years in Japan. In order to estimate the extreme values of TEC, a cumulative distribution function of daily TEC is derived using 22 years of TEC data from 1997 to 2018. The extreme values corresponding to once per year and ten years are 90 and 130 TECU, respectively, in Tokyo, Japan. On the other hand, the 22-year data set is not sufficient to estimate the once-per-hundred-year value. Thus, we use the 62-year data set of manually scaled ionosonde data for the critical frequency of the F-layer (foF2) at Kokubunji in Tokyo. First, we study the relationship between TEC and foF2 for 22 years and investigate the slab thickness. Then the result is applied to the statistical distribution of foF2 data for 62 years. The result shows that the once-per-100-year TEC is about 190 TECU at Tokyo. The value is also estimated to be 230 TECU in Kagoshima and 150 TECU in Hokkaido, in the southern and northern parts of Japan, respectively.

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The Use of the Total Electron Content Measured by Navigation Satellites to Estimate Ionospheric Conditions

International Journal of Navigation and Observation ◽

10.1155/2016/7016208 ◽

2016 ◽

Vol 2016 ◽

pp. 1-15 ◽

Cited By ~ 2

Author(s):

Olga Maltseva ◽

Natalia Mozhaeva

Keyword(s):

Total Electron Content ◽

Critical Frequency ◽

Global Scale ◽

Maximum Density ◽

Slab Thickness ◽

Electron Content ◽

Total Electron ◽

Adequate Accuracy ◽

Critical Frequency Fof2 ◽

Experimental Values

Measurements of delays of the signals radiated by transmitters of navigational satellites allow us to obtain the total electron content (TEC). In addition, measurements of TEC allow solving problems such as development of local, regional, and global models of TEC and correction of ionospheric delay for increasing accuracy of positioning. Now, it is possible to set the task of calculation of critical frequency foF2 with the use of experimental values of TEC in a global scale. For this purpose it is necessary to know an equivalent slab thickness of the ionosphere τ which is a coefficient of proportionality between TEC and a maximum density of the ionosphere. The present paper is devoted to the analysis of investigation and utilization of this parameter. It is shown that (1) existing models of τ are not empirical and not always can provide an adequate accuracy of foF2 calculation, (2) experimental median τ(med) provides much larger accuracy of foF2 calculation than the empirical model and variations from day to day and allows filling gaps in the ionosonde data, and (3) it is possible to use a hyperbolic approximation and coefficient K(τ) for development of a global model of τ.

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The behavior of total electron content and equivalent slab thickness during magnetic disturbances

Journal of Atmospheric and Terrestrial Physics ◽

10.1016/0021-9169(70)90174-1 ◽

1970 ◽

Vol 32 (10) ◽

pp. 1687-1693 ◽

Cited By ~ 3

Author(s):

Jih-Chen Ma

Keyword(s):

Total Electron Content ◽

Slab Thickness ◽

Electron Content ◽

Total Electron ◽

Magnetic Disturbances

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Global equivalent slab thickness model of the Earth’s ionosphere

Journal of Space Weather and Space Climate ◽

10.1051/swsc/2020083 ◽

2021 ◽

Author(s):

Norbert Jakowski ◽

Mohammed Mainul Hoque

Keyword(s):

Solar Activity ◽

Electron Density ◽

Total Electron Content ◽

Local Time ◽

Slab Thickness ◽

Electron Content ◽

Night Time ◽

Total Electron ◽

First Time ◽

Model Approach

The shape of the vertical electron density profile is a result of production, loss and transportation of plasma in the Earth’s ionosphere. Therefore, the equivalent slab thickness of the ionosphere that characterizes the width of vertical electron density profiles is an important parameter for a better understanding of ionospheric processes under regular as well as under perturbed conditions. The equivalent slab thickness is defined by the ratio of the vertical total electron content over the peak electron density and is therefore easy to compute by utilizing powerful data sources nowadays available thanks to ground and space based GNSS techniques. Here we use peak electron density data from three low earth orbiting (LEO) satellite missions, namely CHAMP, GRACE and FORMOSAT-3/COSMIC, as well as total electron content data obtained from numerous GNSS ground stations. For the first time, we present a global model of the equivalent slab thickness (Neustrelitz equivalent Slab Thickness Model – NSTM). The model approach is similar to a family of former model approaches successfully applied for Total Electron Content (TEC), peak electron density NmF2 and corresponding height hmF2 at DLR. The model description focuses on an overall view of the behaviour of the equivalent slab thickness as a function of local time, season, geographic/geomagnetic location and solar activity on a global scale. In conclusion, the model agrees quite well with the overall observation data within a RMS range of 70 km. There is generally a good correlation with solar heat input that varies with local time, season and level of solar activity. However, under non-equilibrium conditions, plasma transport processes dominate the behaviour of the equivalent slab thickness. It is assumed that night-time plasmasphere-ionosphere coupling causes enhanced equivalent slab thickness values like the pre-sunrise enhancement. The overall fit provides consistent results with the mid-latitude bulge (MLB) of the equivalent slab thickness, described for the first time in this paper. Furthermore, the model recreates quite well ionospheric anomalies such as the Night-time Winter Anomaly (NWA) which is closely related to the Mid-latitude Summer Night Anomaly (MSNA) like the Weddell Sea Anomaly (WSA) and Okhotsk Sea Anomaly (OSA). Further model improvements can be achieved by using an extended model approach and considering the particular geomagnetic field structure.

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Statistical analysis of ionospheric total electron content (TEC): Long-term estimation of extreme TEC in Japan

10.21203/rs.3.rs-41992/v3 ◽

2021 ◽

Author(s):

Michi Nishioka ◽

Susumu Saito ◽

Chihiro Tao ◽

Daikou Shiota ◽

Takuya Tsugawa ◽

...

Keyword(s):

Total Electron Content ◽

Communication Systems ◽

Extreme Values ◽

Cumulative Distribution ◽

Propagation Path ◽

Slab Thickness ◽

Electron Content ◽

Data Set ◽

Total Electron ◽

Ionospheric Total Electron Content

Abstract Ionospheric total electron content (TEC) is one of the key parameters for users of radio-based systems, such as the Global Navigation Satellite System, high-frequency communication systems, and space-based remote sensing systems, since total ionospheric delay is proportional to TEC through the propagation path. It is important to know extreme TEC values in readiness for hazardous ionospheric conditions. The purpose of this study is to estimate extreme TEC values with occurrences of once per year, ten years, and hundred years in Japan. In order to estimate the extreme values of TEC, a cumulative distribution function of daily TEC is derived using 22 years of TEC data from 1997 to 2018. The extreme values corresponding to once per year and ten years are 90 and 110 TECU, respectively, in Tokyo, Japan. On the other hand, the 22-year data set is not sufficient to estimate the once-per-hundred-year value. Thus, we use the 62-year data set of manually scaled ionosonde data for the critical frequency of the F-layer (foF2) at Kokubunji in Tokyo. First, we study the relationship between TEC and foF2 for 22 years and investigate the slab thickness. Then the result is applied to the statistical distribution of foF2 data for 62 years. The result shows that the once-per-100-year TEC is about 130-190 TECU at Tokyo. The value is also estimated to be 160-230 TECU in Kagoshima and 100-150 TECU in Hokkaido, in the southern and northern parts of Japan, respectively.

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