Response of the Equatorial Ionosphere to the Annular Solar Eclipse of 15 January 2010

Jose, Lijo; Vineeth, C.; Pant, Tarun Kumar; Kumar, Karanam Kishore

doi:10.1029/2019ja027348

Cited by 10 publications

(11 citation statements)

References 44 publications

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“…The relative foF1 reduction with respect to baseline level was 33% over KTB, and 21.5% over PTK. This relative foF1 reduction is similar to that reported by Jose et al (2020) The significant difference with Adeniyi et al's (2007) findings might be due to the different type of solar eclipse that occurred.…”

Section: Discussionsupporting

confidence: 87%

“…In terms of changes in foF1 during the eclipse, the time delay between maximum eclipse and minimum foF1 over KTB and PTK was 9 minutes and 16 minutes, respectively. This relatively short response time confirms that the ionospheric F1 layer is dominated by production/loss mechanism involving direct photoionization and recombination process, and it is not affected significantly by transport process (Farges et al, 2001;Jose et al, 2020).…”

Section: Discussionsupporting

confidence: 62%

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Ionosonde and GPS Total Electron Content Observations during the 26 December 2019 Annular Solar Eclipse over Indonesia

Harjosuwito

Husin

Dear

et al. 2022

Preprint

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Abstract. We report our investigation of ionospheric effects due to the passage of an annular solar eclipse over Southeast Asia on 26 December 2019, using multiple set of observations. Two ionosondes (one at Kototabang and another at Pontianak) were used to measure dynamical changes in the ionospheric layer during the event. A network of ground-based GPS receiver stations in Indonesia were used to derive the distribution of total electron content (TEC) over the region. In addition, extreme ultraviolet (EUV) images of the Sun from the Atmospheric Imaging Assembly (AIA) instrument on board the Solar Dynamics Observatory (SDO) satellite were also analyzed to determine possible impacts of solar active regions on the changes that occurred in the ionosphere during the eclipse. We found −1.67 MHz and −1.58 MHz reduction (23.2 % and 22.4 % relative reduction) in foF2 during the solar eclipse over Kototabang and Pontianak, respectively. The respective TEC reduction over Kototabang and Pontianak during the eclipse was −4.34 TECU and −5.45 TECU (24.9 % and 27.9 % relative reduction). Overall, there was 34–36 minutes delay from maximum eclipse until minimum foF2 was reached at these two locations. The corresponding time delays for eclipse-related TEC reduction at these two locations were 40 minutes and 16 minutes, respectively. The ionospheric F-layer was found to descend with a speed of 9–19 m/s during the first half of the eclipse period. We also found an apparent rise of the ionospheric F-layer height near the end of the solar eclipse period, equivalent to vertical drift velocity of 44–47 m/s. The GPS TEC data mapping along a set of cross-sectional cut lines indicate that the greatest TEC reduction actually occurred to the north of the solar eclipse path, opposite of the direction from which the lunar shadow fell. As the central path of the solar eclipse was located just to the north of the southern equatorial ionization anomaly (EIA) crest, it is suspected that such a peculiar TEC reduction pattern was caused by plasma flow associated with the equatorial fountain effect. Net perturbations of TEC were also computed and analyzed, which revealed the presence some wavelike fluctuations associated with the solar eclipse event. Some of the observed TEC perturbation patterns that propagated with a velocity matching the lunar shadow may be explained in terms of non-uniform EUV illumination that arose as various active regions on the Sun went obstructed and unobstructed during the eclipse. The remaining wavelike features are likely to be traveling ionospheric disturbances (TIDs) driven by acoustic-gravity waves (AGWs), generated by the passage of the solar eclipse on top of other diurnal factors.

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Section: Discussionsupporting

confidence: 87%

Section: Discussionsupporting

confidence: 62%

Ionosonde and GPS Total Electron Content Observations during the 26 December 2019 Annular Solar Eclipse over Indonesia

Harjosuwito

Husin

Dear

et al. 2022

Preprint

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“…Moreover, the response has been shown to be strongly dependent on latitude (Le, Liu, Yue, & Wan, 2009). At the magnetic equator and low geomagnetic latitudes, the plasma electrodynamic processes dominate the response to the eclipse, particularly the fountain effect and the Equatorial Ionization Anomaly (EIA; Adekoya & Chukwuma, 2016; Bravo et al, 2020; Cheng et al, 1992; Jonah et al, 2020; Jose et al, 2020; Le, Liu, Yue, & Wan, 2009; Madhav Haridas & Manju, 2012; Sridharan et al, 2002; Tomás et al, 2007; Tsai & Liu, 1999).…”

Section: Introductionmentioning

confidence: 99%

“…During the eclipse, the Moon will partially block the solar extreme ultraviolet (EUV) irradiation of the Earth's atmosphere, disturbing the production and dynamics of the ionosphere. The predictability of the sudden decrease and posterior increase of the solar radiation provides an excellent opportunity to experimentally study the ionosphere (Beynon, 1955; Jose et al, 2020; Rishbeth, 1968).…”

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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“…Solar eclipses transiently shield the solar ionizing radiation falling into the atmosphere of the Earth and cause obvious disturbances in the upper atmosphere and ionosphere due to the rapid reduction of solar energy input in the eclipse region. The solar eclipse effects on the ionosphere have been extensively investigated using many different methods including incoherent scatter radars, ionosonde networks, global positioning system (GPS) receivers, and satellite in situ observations (e.g., Afraimovich et al, 1998; Davis et al, 2000; Ding et al, 2010; Goncharenko et al, 2018; Jose et al, 2020; Salah et al, 1986; Stubbe, 1970; Tsai & Liu, 1999; Zhang, Erickson, Goncharenko, Coster & Frissell, 2017; Zhang, Erickson, Goncharenko, Coster, Rideout, et al, 2017), as well as theoretical simulations (e.g., Boitman et al, 1999; Dang et al, 2018; Huba & Drob, 2017; Le et al, 2008a, 2008b, 2009, 2010; Lei et al, 2018; Liu et al, 2000; Müller‐Wodarg et al, 1998). The electron density and temperature are generally reduced in the ionospheric E and F 1 regions due to the rapid reduction of the solar irradiation in the eclipse region.…”

Section: Introductionmentioning

confidence: 99%

Multiple Technique Observations of the Ionospheric Responses to the 21 June 2020 Solar Eclipse

Zhang

et al. 2020

JGR Space Physics

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We investigate the ionospheric response to the 21 June 2020 annular solar eclipse using the multiinstrument observations including ionosondes, Global Navigation Satellite System (GNNS) receivers, COSMIC2, and DMSP and SWARM satellites. During the course of the eclipse, total electron content (TEC) decreased slightly in the morning at 20-70°E and largely in the afternoon at 80-150°E. However, maximum TEC depletion did not occur at the maximum obscuration, but stayed close to the southern edge of the running totality during the eclipse and near the northern edge of the elapsed totality after the eclipse. NmF2 showed the similar variation as TEC around 110°E. Meanwhile, a northward disturbance field-aligned plasma drift was observed in the eclipse region and the disturbance became strong in the southern side of the totality around 120°E. The TEC and Swarm data revealed that the crests of the equatorial ionization anomaly (EIA) enhanced on both sides of the equator around noon in~50-100°E although the northern crest was still in the Moon's shadow. The COSMIC2 profiles displayed the enhanced electron density in~300-500 km altitudes and decreased density below~300 km altitudes around the EIA crests in~70°E. The Swarm observations recorded a drop in the electron temperature both in eclipse region and in conjugate hemisphere in 77°E and 96°E. The combined effect from the electric field, neutral wind, thermal conduction, and interhemispheric photoelectron transport might result in the complicated space and time variations of ionospheric responses to the eclipse.

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Response of the Equatorial Ionosphere to the Annular Solar Eclipse of 15 January 2010

Cited by 10 publications

References 44 publications

Ionosonde and GPS Total Electron Content Observations during the 26 December 2019 Annular Solar Eclipse over Indonesia

Ionosonde and GPS Total Electron Content Observations during the 26 December 2019 Annular Solar Eclipse over Indonesia

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

Multiple Technique Observations of the Ionospheric Responses to the 21 June 2020 Solar Eclipse

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