Evolution of Post‐Sunset EPBs: Relationships to the EIA Induced by Pre‐Reversal Enhancement Electric Fields
Abstract This paper presents Global Navigation Satellite System radio occultation (RO) observational analyses on deducing the relationships and dependences between post‐sunset equatorial plasma bubbles (EPB) occurrences and equatorial ionospheric anomaly (EIA) strength variability. The RO data were...
Saved in:
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Wiley
2025-07-01
|
| Series: | Space Weather |
| Subjects: | |
| Online Access: | https://doi.org/10.1029/2025SW004432 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1849467074390261760 |
|---|---|
| author | Lung‐Chih Tsai Shin‐Yi Su Harald Schuh Mohamad Mahdi Alizadeh Jens Wickert |
| author_facet | Lung‐Chih Tsai Shin‐Yi Su Harald Schuh Mohamad Mahdi Alizadeh Jens Wickert |
| author_sort | Lung‐Chih Tsai |
| collection | DOAJ |
| description | Abstract This paper presents Global Navigation Satellite System radio occultation (RO) observational analyses on deducing the relationships and dependences between post‐sunset equatorial plasma bubbles (EPB) occurrences and equatorial ionospheric anomaly (EIA) strength variability. The RO data were acquired from the FormoSat‐7/Constellation Observing System for Meteorology, Ionosphere and Climate 2 (FS7/COSMIC2) Program from 2020 to 2024. In this study, we incorporate both effects from crest peak electron density (Nemax) and crest‐to‐trough Nemax ratio and propose a new EIA strength parameter defined as the mean of northern and southern crest‐to‐trough Nemax differences to recognize and characterize the post‐sunset EIA features. Both seasonal–longitudinal appearances of intense post‐sunset EPB occurrences and strong EIA events occurred on more or less 30 days expanded from when and where magnetic flux tubes align with the sunset terminator at the magnetic equator but have more intense EPB and/or strong EIA days during southern (northern) hemispheric summers in the South American area (the Central Pacific area and the Africa area). It is well consistent with Tsunoda's hypothesis (Tsunoda, 1985, https://doi.org/10.1029/ja090ia01p00447) during the evening pre‐reversal enhancement and reveals more information on virtual day‐to‐day variability, intensities and extents of post‐sunset EPB occurrences and EIAs subject to seasonal, longitudinal, and solar cycle variabilities. Moreover, the local‐time evolutions of peak post‐sunset EIAs occurred during 19∼20 local time (LT) which is earlier than that of the obtained experimental peak (i.e., 20:20 LT) of post‐sunset EPB occurrences. We expect that the post‐sunset EIA detection could be one of the potential precursors for post‐sunset EPB occurrence. |
| format | Article |
| id | doaj-art-41cac4ccc79a46beb1261209f920b1df |
| institution | Kabale University |
| issn | 1542-7390 |
| language | English |
| publishDate | 2025-07-01 |
| publisher | Wiley |
| record_format | Article |
| series | Space Weather |
| spelling | doaj-art-41cac4ccc79a46beb1261209f920b1df2025-08-20T03:34:53ZengWileySpace Weather1542-73902025-07-01237n/an/a10.1029/2025SW004432Evolution of Post‐Sunset EPBs: Relationships to the EIA Induced by Pre‐Reversal Enhancement Electric FieldsLung‐Chih Tsai0Shin‐Yi Su1Harald Schuh2Mohamad Mahdi Alizadeh3Jens Wickert4Center for Space and Remote Sensing Research National Central University (NCU) Taoyuan TaiwanCenter for Space and Remote Sensing Research National Central University (NCU) Taoyuan TaiwanInstitute of Geodesy and Geoinformation Science Technische Universität Berlin Berlin GermanyInstitute of Geodesy and Geoinformation Science Technische Universität Berlin Berlin GermanyInstitute of Geodesy and Geoinformation Science Technische Universität Berlin Berlin GermanyAbstract This paper presents Global Navigation Satellite System radio occultation (RO) observational analyses on deducing the relationships and dependences between post‐sunset equatorial plasma bubbles (EPB) occurrences and equatorial ionospheric anomaly (EIA) strength variability. The RO data were acquired from the FormoSat‐7/Constellation Observing System for Meteorology, Ionosphere and Climate 2 (FS7/COSMIC2) Program from 2020 to 2024. In this study, we incorporate both effects from crest peak electron density (Nemax) and crest‐to‐trough Nemax ratio and propose a new EIA strength parameter defined as the mean of northern and southern crest‐to‐trough Nemax differences to recognize and characterize the post‐sunset EIA features. Both seasonal–longitudinal appearances of intense post‐sunset EPB occurrences and strong EIA events occurred on more or less 30 days expanded from when and where magnetic flux tubes align with the sunset terminator at the magnetic equator but have more intense EPB and/or strong EIA days during southern (northern) hemispheric summers in the South American area (the Central Pacific area and the Africa area). It is well consistent with Tsunoda's hypothesis (Tsunoda, 1985, https://doi.org/10.1029/ja090ia01p00447) during the evening pre‐reversal enhancement and reveals more information on virtual day‐to‐day variability, intensities and extents of post‐sunset EPB occurrences and EIAs subject to seasonal, longitudinal, and solar cycle variabilities. Moreover, the local‐time evolutions of peak post‐sunset EIAs occurred during 19∼20 local time (LT) which is earlier than that of the obtained experimental peak (i.e., 20:20 LT) of post‐sunset EPB occurrences. We expect that the post‐sunset EIA detection could be one of the potential precursors for post‐sunset EPB occurrence.https://doi.org/10.1029/2025SW004432post‐sunset equatorial plasma bubble (EPB)equatorial ionospheric anomaly (EIA)pre‐reversal enhancement (PRE) electric fieldsGNSS radio occultation (RO) observationionospheric scintillation |
| spellingShingle | Lung‐Chih Tsai Shin‐Yi Su Harald Schuh Mohamad Mahdi Alizadeh Jens Wickert Evolution of Post‐Sunset EPBs: Relationships to the EIA Induced by Pre‐Reversal Enhancement Electric Fields Space Weather post‐sunset equatorial plasma bubble (EPB) equatorial ionospheric anomaly (EIA) pre‐reversal enhancement (PRE) electric fields GNSS radio occultation (RO) observation ionospheric scintillation |
| title | Evolution of Post‐Sunset EPBs: Relationships to the EIA Induced by Pre‐Reversal Enhancement Electric Fields |
| title_full | Evolution of Post‐Sunset EPBs: Relationships to the EIA Induced by Pre‐Reversal Enhancement Electric Fields |
| title_fullStr | Evolution of Post‐Sunset EPBs: Relationships to the EIA Induced by Pre‐Reversal Enhancement Electric Fields |
| title_full_unstemmed | Evolution of Post‐Sunset EPBs: Relationships to the EIA Induced by Pre‐Reversal Enhancement Electric Fields |
| title_short | Evolution of Post‐Sunset EPBs: Relationships to the EIA Induced by Pre‐Reversal Enhancement Electric Fields |
| title_sort | evolution of post sunset epbs relationships to the eia induced by pre reversal enhancement electric fields |
| topic | post‐sunset equatorial plasma bubble (EPB) equatorial ionospheric anomaly (EIA) pre‐reversal enhancement (PRE) electric fields GNSS radio occultation (RO) observation ionospheric scintillation |
| url | https://doi.org/10.1029/2025SW004432 |
| work_keys_str_mv | AT lungchihtsai evolutionofpostsunsetepbsrelationshipstotheeiainducedbyprereversalenhancementelectricfields AT shinyisu evolutionofpostsunsetepbsrelationshipstotheeiainducedbyprereversalenhancementelectricfields AT haraldschuh evolutionofpostsunsetepbsrelationshipstotheeiainducedbyprereversalenhancementelectricfields AT mohamadmahdializadeh evolutionofpostsunsetepbsrelationshipstotheeiainducedbyprereversalenhancementelectricfields AT jenswickert evolutionofpostsunsetepbsrelationshipstotheeiainducedbyprereversalenhancementelectricfields |