Articles | Volume 44, issue 2
https://doi.org/10.5194/angeo-44-631-2026
© Author(s) 2026. This work is distributed under the Creative Commons Attribution 4.0 License.
Special issue:
Tracking ionospheric changes during solar eclipses: Concepción historical data
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- Final revised paper (published on 07 Jul 2026)
- Preprint (discussion started on 13 Nov 2025)
Interactive discussion
Status: closed
Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor
| : Report abuse
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RC1: 'Comment on egusphere-2025-5416', Anonymous Referee #1, 14 Dec 2025
- AC1: 'Reply on RC1', Manuel Bravo, 21 Jan 2026
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RC2: 'Comment on egusphere-2025-5416', Anonymous Referee #2, 16 Mar 2026
- AC2: 'Reply on RC2', Manuel Bravo, 10 Apr 2026
Peer review completion
AR – Author's response | RR – Referee report | ED – Editor decision | EF – Editorial file upload
ED: Publish subject to technical corrections (27 Apr 2026) by Geeta Vichare
ED: Publish subject to minor revisions (review by editor) (28 Apr 2026) by Geeta Vichare
AR by Manuel Bravo on behalf of the Authors (21 May 2026)
Author's response
Author's tracked changes
Manuscript
ED: Publish as is (28 May 2026) by Geeta Vichare
AR by Manuel Bravo on behalf of the Authors (07 Jun 2026)
Manuscript
I consider that this is a valuable work. On one side, it gathers many historical data, and this is something that in my opinion is extremely important since it implies data preservation, control and also their digitalization, which is a complex task considering that some of the records had flaws and damages. So, this is a key contribution of this work.
I also find it valuable the identification of the eclipses together with the ionosonde data for the corresponding periods. Even if most of them are not adequate for analyzing the effect of the eclipses on the ionosphere parameters as the authors intended to.
Another valuable aspect, is the analysis focusing on the effect on the critical frequencies (foE, foF1 and foF2) of the maximum darkness of each eclipse, instead of the effect of the different degrees of obscuration within a given eclipse. This is novel to me.
Based on all this, I consider that this work should be accepted for publication but it needs a major revision. Following are my comments and suggestions:
Major comments:
(1) In the Abstract it is written "Regression analysis was performed exclusively on critical frequencies, revealing a nearly linear decrease of foE with increasing solar obscuration"
This looks like you analyze the dependence with the obscuration along an eclipse. And this is not what is done in this work. Or at least what I understood. You analyze the dependence with the maximum obscuration of an eclipse.
I think this should be stated clearly in the abstract. In fact, this is the novelty of the work, in addition to the valuable work of collecting the data. Even though the results obtained, in my opinion, lack statistical significance, and a more clear explanation of the method and exclusion of events and data are needed.
(2) In the Introduction, the authors mention that the "purpose of this work is to characterize the response of the Concepción (36.79°S, 73.03°W) ionosphere under solar eclipse conditions over several solar cycles, so that its response can be associated with parameters such as the amount of darkness, season, time of day, etc., in order to predict the response for future eclipses." but you do not do all this because the limitations in the data.
In fact, the effect you analyze is of the maximum obscuration per eclipse over ionospheric parameters.
I do not see either the analysis of this effect in terms of time or solar cycle phase.
In Figure 4 I see all the four events selected without any discrimination.
I think that either you can mention that this was the initial purpose, before gathering the data, and explain then that the work is more like a compilation of data during eclipse events (which is very valuable, even if the data are not well suited for the analysis you do), or state from the beginning what is made in this work. And also mention clearly that you analyze not the effect of the obscuration degree within a given eclipse but of the effect of the maximum obscuration per eclipse.
I understand that this is not an easy task, since precisely, you have to gather data of many events, which are not so frequent.
(3) From 21 periods, only 4 are analyzed. Statistically this means something. First you discard those eclipses without data. But then you select 4 within those with data, which show an effect.
Those not included means something to your statistics. If you have for example 10 eclipses and only in 4 you detect the effect, the phenomenon detected has also a percentage of occurrence. Which in the case of being 4 to 10, it will be 40 %. With which the significance of your regression coefficients are even lower.
(4) I think that you choose one single point of foE, foF1 and foF2 for each of the four selected eclipses. Do you think that the time resolution of the data may have some influence? Since it is not the same if you choose an foE data, for example, from a time series with 5 minute resolution, than if you have a 15 minute resolution. Unless the variability of the percentage of darkness within an eclipse around the maximum darkness, varies very slowly. Please explain this.
(5) About Figure 4. What are the statistical significance of these regressions? You have very few points; only four.
(6) In the Conclusion: "This work analyzed the response of the Concepción/Chillán ionosphere to 16 selected solar eclipses ..." You did not analyze all them. You have gathered the data, and presented them. But you have analyzed only 4 events. Unless you discuss also the events which you do not include in the regression analysis.
I think that you should clearly mention which are your valid results, and also explain the difficulties on carrying a study like this.
For example, that even if you have the data, they have many times gaps which prevent the study, or due to the analysis has to be based on high temporal resolution data, the disturbances are more notorious and blur the eclipse effect, for example. I assume you may have more arguments.
Or may be I am wrong. So please, elaborate on this.
(7) A data availability section is missing, which I think is very important. You should say where are the data available, or at least how anyone can have access to them.
Minor comments:
(1) In the abstract: "Concepción (36.79°S, 73.03°W/Chillán (36.64°S, 71.99°W)" should be" Concepción (36.79°S, 73.03°W)/Chillán (36.64°S, 71.99°W)"
(2) h’F2/F ? Shouldn't it be just h'F2 ?
(3) Line 47: Smith and King, 1981; Bremer, 1992; Ortiz de Adler et al., 1997; Jarvis et al., 1998; Foppiano et al., 1999 ... The years should go between parenthesis.
(4) Line 91: "(1957–1994," should be "(1957–1994),"
(5) Line 101: "Software de Corrección de Ionogramas (SoCIo)". Which is it source ? or reference ?
(6) Figure 1: In the panel showing Eclipse on 13-11-2012 the dashed line indicating maximum darkness is missing, since it coincides with the End time. What does this mean? Why isn't there a period after maximum darkness of recovery?
(7) 18-3-87 is also missing the dashed line indicating maximum darkness. In this case I can see it coincides with the beginning. Why this happens?
(8) Figure 4: I think the the last panels correspond to delta F2. Please check.
(9) Line 181: Which are the four selected events? You should mention them clearly
(10) Line 206: "This degradation reflects the additional variability introduced by diurnal, seasonal, and solar cycle variations in baseline foE values" In the case of percentage values you can assume that you are kind of independent of hour or solar cycle phase, since you are dividing the difference in each parameter by the median value. So I would expect an effect when you consider the absolute difference, not the relative. Please explain.