How does solar eclipse influence the complex behavior of midlatitude ionosphere? Two case studies

Unnikrishnan, K. P.; Richards, P. G.

doi:10.1002/2013ja018708

Cited by 5 publications

(2 citation statements)

References 48 publications

(100 reference statements)

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“…When the chromosphere irradiance was assumed to be zero at totality, it was found that 30% coronal emission remaining at totality gave the best fit to the electron density variation at 150 km and C = 0.3 was used for all the calculations in this article. Some previous eclipse calculations have used the same obscuration factor for all EUV wavelengths (e.g., Unnikrishnan & Richards, ). This assumption does not lead to serious error for partial eclipses where there is substantial emission from the solar disk, but the effect is significant when there is near total obscuration of the disk.…”

Section: Resultsmentioning

confidence: 99%

Investigation of the Electron Density Variation During the 21 August 2017 Solar Eclipse

Reinisch

Dandenault

Galkin

et al. 2018

Geophysical Research Letters

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This paper presents a comparison of modeled and measured electron densities for the 21 August 2017 solar eclipse across the USA. The location of the instrument was (43.81°N, 247.32°E) where the maximum obscuration of 99.6% occurred at 17.53 hr UT on 21 August. The solar apparent time was 9.96 hr, and the duration of the eclipse was 2.7 hr. It was found that if it is assumed that there are no chromosphere emissions at totality, ~30% coronal emission remaining at totality gave the best fit to the electron density variation at 150 km. The 30% coronal emission estimate has uncertainties associated with respect to uncertainties in the solar spectrum, the measured electron density, and the amount of chromosphere emissions remaining at totality. The agreement between the modeled and measured electron densities is excellent at 150 km with the assumed 30% coronal emission at totality. At other altitudes, the agreement is very good, but the altitude profile would be improved if the model peak electron density (NmF2) decayed more slowly to better match the data. The minimum NmF2 in the model occurs ~10 min after totality when it decreases to 0.55 from its noneclipse value. The minimum of the NmF2 data occurs between 6 and 10 min after totality but is ~15% larger. The total electron content decreases to 0.65 of its preeclipse value. These relative changes agree well with those predicted by others prior to the eclipse.

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Section: Resultsmentioning

confidence: 99%

Investigation of the Electron Density Variation During the 21 August 2017 Solar Eclipse

Reinisch

Dandenault

Galkin

et al. 2018

Geophysical Research Letters

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“…Many different ionospheric models have been used to determine the effects of eclipses, such as the NCAR model (Roble et al, 1986; Salah et al, 1986), CTIP (Müller‐Wodarg et al, 1998), SUPIM (Bravo et al, 2020; MacPherson et al, 2000), TIME‐IGGCAS (Le et al, 2008a, 2008b; Le, Liu, Yue, & Wan, 2009; Le, Liu, Yue, Wan, & Ning, 2009; Le et al, 2010), SAMI3 (Huba & Drob, 2017), FLIP (Reinisch et al, 2018; Unnikrishnan & Richards, 2014), GITM (Cnossen et al, 2019; Wu et al, 2018), TIEGCM (Chen et al, 2019; Dang et al, 2018, 2020; Lei et al, 2018; Wang et al, 2019), WACCM‐X (McInerney et al, 2018), and an empirical ionospheric model based on measurements of the Millstone Hill incoherent scatter radar (ISR; Goncharenko et al, 2018). However, few studies estimate the ionospheric impacts prior to eclipses occurrence (Dang et al, 2020; Huba & Drob, 2017; Müller‐Wodarg et al, 1998).…”

Section: Introductionmentioning

confidence: 99%

Prediction of the Ionospheric Response to the 14 December 2020 Total Solar Eclipse Using SUPIM‐INPE

et al. 2020

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We present the first prediction of the ionospheric response to the 14 December 2020 solar eclipse using the SUPIM-INPE model. Simulations are made for all known ionosonde stations for which solar obscuration is significant. The found response is similar to that previously reported for other eclipses, but it also shows a modification of the equatorial fountain transport that will impact the low latitudes after the event. In addition to the large reduction of electron concentration along the totality path (~4.5 TECu, 22%), a significant electron and oxygen ion temperature cooling is observed (up to~400 K) followed by lasting temperature increases. Changes of up to~1.5 TECu (~5%) are also expected at the conjugate hemisphere. These predictions may serve as a reference for eventual ionospheric measurements of multiple instruments and are leading to a better understanding of the ionospheric response to solar eclipses.

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Nonextensive and distance-based entropy analysis on the influence of sunspot variability in magnetospheric dynamics

Gopinath

Prince

2018

Acta Geod Geophys

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How does solar eclipse influence the complex behavior of midlatitude ionosphere? Two case studies

Cited by 5 publications

References 48 publications

Investigation of the Electron Density Variation During the 21 August 2017 Solar Eclipse

Investigation of the Electron Density Variation During the 21 August 2017 Solar Eclipse

Prediction of the Ionospheric Response to the 14 December 2020 Total Solar Eclipse Using SUPIM‐INPE

Nonextensive and distance-based entropy analysis on the influence of sunspot variability in magnetospheric dynamics

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