Quiet and Disturbed Time Characteristics of Blanketing Es (Esb) During Solar Cycle 23

Yadav, Virendra; Kakad, Bharati; Bhattacharyya, A.; Pant, Tarun Kumar

doi:10.1002/2017ja023911

Cited by 7 publications

(8 citation statements)

References 59 publications

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“…Another current system is the EEJ, which is an eastward current flowing in a narrow latitudinal belt (±3°) over the magnetic equator in the E-region. The hourly values of horizontal component of the ground magnetic field (H) recorded at Alibag and Tirunelveli/Trivandrum are used to estimate the strength of EEJ on nth day at local time t = 1-24 as follows (Yadav et al, 2017):…”

Section: Data Sets and Energy Estimatesmentioning

confidence: 99%

Diminishing activity of recent solar cycles (22–24) and their impact on geospace

Kakad

Ramesh

et al. 2019

J. Space Weather Space Clim.

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This study examines the variation of different energies linked with the Sun and the Earth’s magnetosphere-ionosphere systems for solar cycles (SCs) 22–24 for which the gradual decrease in the solar activity is noticed. Firstly, we investigated the variation of solar magnetic energy density (SMED) for SCs 21–24 and its relation to the solar activity. We observed distinct double peak structures in SMED for the past four SCs, 21–24. This feature is consistent with noticeable asymmetry in their two peaks. For SCs 22–24 a significant decrease is observed in the integrated SMED of each SC. This reduction is 37% from SCs 22 to 23 and 51% from SCs 23 to 24, which indicates substantial weakening of Sun’s magnetic field for SC 24. Also, the magnetic, kinetic, and thermal energy densities at the Earth’s bow-shock nose are found to be considerably low for the SC 24. We examined the solar wind Alfven speed, magnetosonic Mach number, solar wind-magnetosphere energy coupling parameter (ε), and the Chapman-Ferraro magnetopause distance (LCF) for the SCs 22–24. The estimated maximum stand-off magnetopause distance is larger for SC 24 (LCF ≤ 10.6 RE) as compared to SC 23 (LCF ≤ 10.2 RE) and SC 22 (LCF ≤ 9.8 RE). The solar wind Alfven speeds during SCs 22 and 23 are in the same range and do not exceed ≈73 km/s whereas, it is below 57 km/s for SC 24. A lower bound of solar wind magnetosonic Mach number for SC 24 is larger (M ≥ 6.9) as compared to SC 22 (M ≥ 5.9) and SC 23 (M ≥ 6). We noticed weakening in the energy coupling parameter for SC 24, which resulted in substantial (15%–38%) decrease in average strength of high latitude ionospheric (AE), low latitude magnetospheric (Dst) and equatorial ionospheric (EEJ) current systems in comparison with SC 23. Subsequently, a reduction of ≈30% is manifested in the high latitude Joule heating for SC 24. Overall this study indicates the significant step down in various energies at Sun, Earth’s bow-shock, and near Earth environment for current SC 24, which will have important implication on our Earth’s atmosphere-ionosphere-magnetosphere system.

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Section: Data Sets and Energy Estimatesmentioning

confidence: 99%

Diminishing activity of recent solar cycles (22–24) and their impact on geospace

Kakad

Ramesh

et al. 2019

J. Space Weather Space Clim.

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“…Sporadic-E manifests itself as a non-uniform, wavy layer, or a composition of irregular elongated clouds of intense ionization within the lower E-region of the ionosphere [1,4]. There are many methods and instruments used to monitor sporadic-E including incoherent scatter radars (ISRs) [5], ionosondes [6][7][8][9][10], and GPS radio occultation (RO) [11,12]. While ISR measurements provide detailed E s observations, the number of sites across the globe are significantly lacking for global climatological studies.…”

Section: Introductionmentioning

confidence: 99%

A Comparison of Sporadic-E Occurrence Rates Using GPS Radio Occultation and Ionosonde Measurements

2022

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Sporadic-E (Es) occurrence rates from Global Position Satellite radio occultation (GPS-RO) measurements have shown to vary by a factor of five between studies, motivating the need for a comparison with ground-based measurements. In an attempt to find accurate GPS-RO techniques for detecting Es formation, occurrence rates derived using five previously developed GPS-RO techniques are compared to ionosonde measurements over an eight-year period from 2010–2017. GPS-RO measurements within 170 km of a ionosonde site are used to calculate Es occurrence rates and compared to the ground-truth ionosonde measurements. The techniques are compared individually for each ionosonde site and then combined to determine the most accurate GPS-RO technique for two thresholds on sporadic-E intensity: no lower limit and fbEs ≥3 MHz. Overall, the YuS4 method shows the closest agreement with ionosonde measurements for total Es occurrence rates without a lower limit on intensity, while the phase-based Chu technique shows the closest agreement for fbEs ≥3 MHz. This analysis demonstrates that the variation in GPS-RO derived sporadic-E occurrence rates is due to varying thresholds on the sporadic-E intensities in terms of fbEs.

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“…This is quite expected. The previous studies using GPS RO (Arras et al, 2008;Chu et al, 2014;Wu et al, 2005;Yu et al, 2019) and ionosonde measurements (Jo et al, 2019;Yadav et al, 2017;Zhou et al, 2017) reported this summer maximum dependence. Haldoupis et al (2007) explained this seasonal behavior in terms of the maximum meteor influx during summer in the Northern Hemisphere.…”

Section: Statistical Characteristics Of the Es B Layersmentioning

confidence: 66%

“…The occurrences of Es b layers have been studied on a global scale using satellite data (Arras & Wickert, 2018; Chu et al., 2014; Luo et al., 2021; Wu et al., 2005; Yu et al., 2019; Yue et al., 2016) and overhead at some ionospheric stations with ground‐based radar such as ionosondes (Abdu et al., 1996; Andrioli et al., 2022; Conceição‐Santos et al., 2019; Jo et al., 2019; Pignalberi et al., 2014; Resende et al., 2017b; Yadav et al., 2017; Zhou et al., 2017).…”

Section: Introductionmentioning

confidence: 99%

“…Zhou et al (2017) did not classify the Es layers in terms of the observed types, and also, the fbEs values were not studied. Yadav et al (2017) studied the Es b layers in terms of their characteristics during magnetically quiet and disturbed time in Trivandrum (8.5°N, 76.6°E, GL = 0.2°S), an Indian dip equatorial station. The authors found, among other results, that the highest occurrence of the Es b is in summer.…”

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confidence: 99%

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Blanketing Sporadic‐E Layer Occurrences Over Santa Maria, a Transition Station From Low to Middle Latitude in the South American Magnetic Anomaly (SAMA)

Moro

Nardin

et al. 2022

JGR Space Physics

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The sporadic E (Es) is the widely known thin ionization layers, often very dense compared to the background electron density, occurring in the E-region heights (Haldoupis, 2012;Mathews, 1998;Whitehead, 1989). They can present distinct properties produced by different formation mechanisms such as neutral wind shear (most effective in the middle latitude region), plasma instability, convective electric field, and charged particle precipitations depending upon the characteristics of the geomagnetic field where they are observed (Abdu &

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Quiet and Disturbed Time Characteristics of Blanketing Es (Esb) During Solar Cycle 23

Cited by 7 publications

References 59 publications

Diminishing activity of recent solar cycles (22–24) and their impact on geospace

Diminishing activity of recent solar cycles (22–24) and their impact on geospace

A Comparison of Sporadic-E Occurrence Rates Using GPS Radio Occultation and Ionosonde Measurements

Blanketing Sporadic‐E Layer Occurrences Over Santa Maria, a Transition Station From Low to Middle Latitude in the South American Magnetic Anomaly (SAMA)

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