Linear Vary-Chap Topside Electron Density Model with Topside Sounder and Radio-Occultation Data

Prol, Fabricio dos Santos; Themens, David R.; Hernández‐Pajares, Manuel; Camargo, Paulo de Oliveira; Muella, M. T. A. H.

doi:10.1007/s10712-019-09521-3

Cited by 28 publications

(43 citation statements)

References 26 publications

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“…Then, the linear trend of the topside scale height is a very well defined topside ionospheric feature, regardless of geophysical conditions. It is worth noting that these results are valid until about 800 km of height (the maximum height covered by COSMIC satellites); for higher altitudes it has been demonstrated that a departure from the linearity takes place 14 .…”

Section: Results Of Figs 4 and 5 Confirm What Preliminarily Found Bymentioning

confidence: 64%

“…To be valuable for operational purposes, it is desirable that relations (14) and (16) are valid (within few percent of error) also in the lower topside ionosphere, i.e., in the region between the F2-layer peak (highly variable between around 200 and 400 km) and the upper transition height (the height that separates the ionosphere from the plasmasphere, highly variable in a wide range of altitudes around 1000 km). In order to verify this desired behavior, we further developed the calculation, with the change of variable z = n • 2H Epstein (z) , n ∈ R + 0 , and evaluated VSH and corresponding derivatives through Eqs.…”

Section: Correspondingly Eq (4) Can Be Written Asmentioning

confidence: 99%

“…The Pignalberi et al 13 approach is first applied to the entire COSMIC dataset to retrieve effective scale height parameters on a global basis and for different helio-geophysical conditions. After that, a preliminary (14) lim…”

Section: A Preliminary Application Based On Cosmic/formosat-3 Radio Omentioning

confidence: 99%

“…Different functions were applied by several authors, the most popular being exponential, Chapman, and Epstein families of functions 12 , 20 – 24 . The first studies were based on constant H values, but the growing bulk of topside measurements suggested the need to allow for an increasing trend of H with altitude 13 , 14 , 25 – 27 . This is why the most recent topside models are based on effective scale heights varying with altitude.…”

Section: Introductionmentioning

confidence: 99%

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On the link between the topside ionospheric effective scale height and the plasma ambipolar diffusion, theory and preliminary results

Pignalberi

Pezzopane

Nava

et al. 2020

Sci Rep

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Over the years, an amount of models relying on effective parameters were implemented in the challenging issue of the topside ionosphere description. These models are based on different analytical functions, but all of them depend on a parameter called effective scale height, that is deduced from topside electron density measurements. As their names state, they are effective in reproducing the topside electron density profile only when applied to the analytical function used to derive them. Then, in principle, they do not have any physical meaning. It is the goal of this paper to mathematically link the effective scale height modeled through the Epstein layer to the vertical scale height theoretically deduced from the plasma ambipolar diffusion theory. Firstly, effective and theoretical scale heights are linked through a mathematical relation by showing that they tend to each other in the topside ionosphere. Secondly, their connection is preliminarily demonstrated by calculating effective scale height values from the entire COSMIC/FORMOSAT-3 radio occultation dataset. Thirdly, a possible connection between the vertical gradient of the topside scale height (as obtained by COSMIC/FORMOSAT-3 satellites) and the electron temperature (as obtained by ESA Swarm B satellite) is studied by highlighting corresponding similarities in the diurnal, seasonal, solar activity, and latitudinal variability.

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Section: Results Of Figs 4 and 5 Confirm What Preliminarily Found Bymentioning

confidence: 64%

Section: Correspondingly Eq (4) Can Be Written Asmentioning

confidence: 99%

Section: A Preliminary Application Based On Cosmic/formosat-3 Radio Omentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

On the link between the topside ionospheric effective scale height and the plasma ambipolar diffusion, theory and preliminary results

Pignalberi

Pezzopane

Nava

et al. 2020

Sci Rep

View full text Add to dashboard Cite

show abstract

“…This approach to modeling the topside has been applied before, demonstrating acceptable performance below 1,200‐km altitudes (dos Santos Prol et al, 2019). For the bottomside ionosphere, the expression for the scale height is as follows:

H false(h false) = A_{2} false(h - h_{m} F_{2} false) + H_{m 2} .

…”

Section: Data Preprocessingmentioning

confidence: 99%

Ionospheric Vertical Correlation Distances: Estimation From ISR Data, Analysis, and Implications For Ionospheric Data Assimilation

et al. 2021

Self Cite

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The construction of the background covariance matrix is an important component of ionospheric data assimilation algorithms, such as Ionospheric Data Assimilation Four‐Dimensional (IDA4D). It is a matrix that describes the correlations between all the grid points in the model domain and determines the transition from the data‐driven to model‐driven regions. The vertical component of this matrix also controls the shape of the assimilated electron density profile. To construct the background covariance matrix, the information about the spatial ionospheric correlations is required. This paper focuses on the vertical component of the model covariance matrix. Data from five different incoherent scatter radars (ISR) are analyzed to derive the vertical correlation lengths for the International Reference Ionosphere (IRI) 2016 model errors, because it is the background model for IDA4D. The vertical distribution of the correlations is found to be asymmetric about the reference altitude around which the correlations are calculated, with significant differences between the correlation lengths above and below the reference altitude. It is found that the correlation distances not only increase exponentially with height but also have an additional bump‐on‐tail feature. The location and the magnitude of this bump are different for different radars. Solar flux binning introduces more pronounced changes in the correlation distances in comparison to magnetic local time (MLT) and seasonal binning of the data. The latitudinal distribution of vertical correlation lengths is presented and can be applied to the construction of the vertical component of the background model covariance matrix in data assimilation models that use IRI or similar empirical models as the background.

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Characteristics of the Effective Scale Height in the Topside Ionosphere Extracted from Swarm A and Digisonde Observations: preliminary results

Belehaki

Tsagouri

Paouris

2021

Preprint

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Linear Vary-Chap Topside Electron Density Model with Topside Sounder and Radio-Occultation Data

Cited by 28 publications

References 26 publications

On the link between the topside ionospheric effective scale height and the plasma ambipolar diffusion, theory and preliminary results

On the link between the topside ionospheric effective scale height and the plasma ambipolar diffusion, theory and preliminary results

Ionospheric Vertical Correlation Distances: Estimation From ISR Data, Analysis, and Implications For Ionospheric Data Assimilation

Characteristics of the Effective Scale Height in the Topside Ionosphere Extracted from Swarm A and Digisonde Observations: preliminary results

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