Results of the modeling of the topside electron density profile using the Chapman and Epstein functions

Zhang, M.L.; Radicella, S. M.; Kersley, L.; Пулинец, С. А.

doi:10.1016/s0273-1177(02)00053-4

Cited by 6 publications

(5 citation statements)

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“…The Chapman's shape factor exhibits a high correlation with the F 2 layer peak electron density and shows a strong solar cycle dependence during the late morning hours. Zhang et al () tried to model the topside ionosphere by fitting the α‐Chapman and Epstein functions, with a linearly variable effective scale height, to ISR profiles collected in Malvern (52.1°N, 2.3°W). They found that topside profiles can be fitted very well (about 94% of profiles met the criterion ε < 10%, ε being the percentage difference between modeled and measured topside electron density values) to a height of about 400 km above the F 2 peak using either functions.…”

Section: Methodsmentioning

confidence: 99%

Modeling the Lower Part of the Topside Ionospheric Vertical Electron Density Profile Over the European Region by Means of Swarm Satellites Data and IRI UP Method

2018

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An empirical method to model the lower part of the ionospheric topside region from the F2 layer peak height to about 500–600 km of altitude over the European region is proposed. The method is based on electron density values recorded from December 2013 to June 2016 by Swarm satellites and on foF2 and hmF2 values provided by IRI UP (International Reference Ionosphere UPdate), which is a method developed to update the IRI model relying on the assimilation of foF2 and M(3000)F2 data routinely recorded by a network of European ionosonde stations. Topside effective scale heights are calculated by fitting some definite analytical functions (α‐Chapman, β‐Chapman, Epstein, and exponential) through the values recorded by Swarm and the ones output by IRI UP, with the assumption that the effective scale height is constant in the altitude range considered. Calculated effective scale heights are then modeled as a function of foF2 and hmF2, in order to be operationally applicable to both ionosonde measurements and ionospheric models, like IRI. The method produces two‐dimensional grids of the median effective scale height binned as a function of foF2 and hmF2, for each of the considered topside profiles. A statistical comparison with Constellation Observing System for Meteorology, Ionosphere, and Climate/FORMOsa SATellite‐3 collected Radio Occultation profiles is carried out to assess the validity of the proposed method and to investigate which of the considered topside profiles is the best one. The α‐Chapman topside function displays the best performance compared to the others and also when compared to the NeQuick topside option of IRI.

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Section: Methodsmentioning

confidence: 99%

Modeling the Lower Part of the Topside Ionospheric Vertical Electron Density Profile Over the European Region by Means of Swarm Satellites Data and IRI UP Method

2018

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“…The introduction of a height‐dependent scale height into a Chapman α or Chapman β layer can closely match the observed topside profile [ Fox , 1994; Zhang et al , 2002; Lei et al , 2004, 2005]. However, a detailed dependence of the topside scale height with height has not yet been developed.…”

Section: Introductionmentioning

confidence: 99%

A study of the shape of topside electron density profile derived from incoherent scatter radar measurements over Arecibo and Millstone Hill

et al. 2006

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[1] The shape of the topside electron density (Ne) profile is studied using incoherent scatter radar (ISR) measurements. On the basis of more than 90,000 and 84,000 Ne profiles measured over Arecibo (18.4°N, 66.7°W, dip 49.7°) and Millstone Hill (42.6°N, 71.5°W, dip 71.6°), respectively, shape factors have been derived by fitting the ISR observed profile using a Chapman-type layer with a height-independent scale height. The results reveal that the shape factor shows a general departure from the typically used values of 0.5 (Chapman a layer) except during the night and also undergoes appreciable variation with local time, season, solar activity, and latitude. Over Arecibo, the averaged shape factor is characterized by a daytime maximum of $0.55-0.75, a nearly constant nighttime value close to 0.5, and a marked morning decline; over Millstone Hill, the shape factor shows pronounced seasonal variations, and the diurnal variation in summer is opposite to that in other seasons. Over both stations, the shape factor exhibits a high correlation with the F 2 layer peak electron density (N m F 2 ), and it has strong solar cycle dependence during the late morning hours. It indicates that the temperature structure of the topside ionosphere can explain much of the variation of the shape factor when the plasma density is low, especially during nighttime. During daytime hours, the topside shape factor is thought to be associated with ion-neutral drag during periods of large plasma density.Citation: Luan, X., L. Liu, W. Wan, J. Lei, S.-R. Zhang, J. M. Holt, and M. P. Sulzer (2006), A study of the shape of topside electron density profile derived from incoherent scatter radar measurements over Arecibo and Millstone Hill, Radio Sci., 41, RS4006,

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“…The most established ionospheric models, the International Reference Ionosphere (IRI) model [11] and the NeQuick model [12] are not always able to properly represent the real features of the topside ionosphere [13]- [15]; therefore, further studies aimed at improving their topside representation are needed [16]. A part of the debate includes the choice of the mathematical function to use for the topside electron density vertical representation, the most popular being the Chapman [17] or Epstein [18], [19] families of functions [3], [20]- [22].…”

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On the Analytical Description of the Topside Ionosphere by NeQuick: Modeling the Scale Height Through COSMIC/FORMOSAT-3 Selected Data

Pignalberi

Pezzopane

Themens

et al. 2020

IEEE J. Sel. Top. Appl. Earth Observations Remote Sensing

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The analytical description of the topside ionosphere included in the NeQuick model is studied in detail. First, the modeled scale height behavior is analyzed at infinity and for the lowest part of the topside region; in the latter case, the analysis is done through an expansion in Taylor series near the F2-layer peak. Moreover, the significant influence of the three NeQuick topside parameters in the modeling of the topside profile is investigated in detail and, in particular, it is shown that for the lowest part of the topside the model assumes a linearly increasing trend of the topside scale height. Second, the topside formulation is inverted to derive a fully analytical expression of the topside scale height as a function of the electron density and F2-layer peak parameters. This expression has been applied to a selected and very reliable dataset of Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC)/FORMOSAT-3 radio occultation profiles. Statistical analyses strongly support the hypothesis embedded in NeQuick regarding the linear trend of the topside scale height for the lowest part of the topside. Index Terms-Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC)/FORMOSAT-3 radio occultation data, NeQuick model, topside ionosphere modeling, topside scale height. I. INTRODUCTION T HE topside part of the ionosphere extends from the height of the F2-layer peak, corresponding to the ionospheric electron density maximum (NmF2), to the plasmasphere [1]. Developing a reliable model of the topside ionosphere is one of the most difficult tasks because instruments commonly used

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Results of the modeling of the topside electron density profile using the Chapman and Epstein functions

Cited by 6 publications

References 0 publications

Modeling the Lower Part of the Topside Ionospheric Vertical Electron Density Profile Over the European Region by Means of Swarm Satellites Data and IRI UP Method

Modeling the Lower Part of the Topside Ionospheric Vertical Electron Density Profile Over the European Region by Means of Swarm Satellites Data and IRI UP Method

A study of the shape of topside electron density profile derived from incoherent scatter radar measurements over Arecibo and Millstone Hill

On the Analytical Description of the Topside Ionosphere by NeQuick: Modeling the Scale Height Through COSMIC/FORMOSAT-3 Selected Data

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