scholarly journals Ionospheric response to total solar eclipse of 22 July 2009 in different Indian regions

2013 ◽  
Vol 31 (9) ◽  
pp. 1549-1558 ◽  
Author(s):  
S. Kumar ◽  
A. K. Singh ◽  
R. P. Singh
Keyword(s):  
Total Electron Content ◽  
Solar Eclipse ◽  
Total Solar Eclipse ◽  
Lower Atmosphere ◽  
Electron Content ◽  
Vertical Total Electron Content ◽  
Total Electron ◽  
Ionospheric Response ◽  
Total Electron Content Data ◽  
Photoionization Process

Abstract. The variability of ionospheric response to the total solar eclipse of 22 July 2009 has been studied analyzing the GPS data recorded at the four Indian low-latitude stations Varanasi (100% obscuration), Kanpur (95% obscuration), Hyderabad (84% obscuration) and Bangalore (72% obscuration). The retrieved ionospheric vertical total electron content (VTEC) shows a significant reduction (reflected by all PRNs (satellites) at all stations) with a maximum of 48% at Varanasi (PRN 14), which decreases to 30% at Bangalore (PRN 14). Data from PRN 31 show a maximum of 54% at Kanpur and 26% at Hyderabad. The maximum decrement in VTEC occurs some time (2–15 min) after the maximum obscuration. The reduction in VTEC compared to the quiet mean VTEC depends on latitude as well as longitude, which also depends on the location of the satellite with respect to the solar eclipse path. The amount of reduction in VTEC decreases as the present obscuration decreases, which is directly related to the electron production by the photoionization process. The analysis of electron density height profile derived from the COSMIC (Constellation Observing System for Meteorology, Ionosphere & Climate) satellite over the Indian region shows significant reduction from 100 km altitude up to 800 km altitude with a maximum of 48% at 360 km altitude. The oscillatory nature in total electron content data at all stations is observed with different wave periods lying between 40 and 120 min, which are attributed to gravity wave effects generated in the lower atmosphere during the total solar eclipse.

The effect of total solar eclipse of October 3, 2005, on the total electron content over Europe

2008 ◽  
Vol 41 (4) ◽  
pp. 628-638 ◽  
Author(s):  
A. Krankowski ◽  
I.I. Shagimuratov ◽  
L.W. Baran ◽  
G.A. Yakimova
Keyword(s):  
Total Electron Content ◽  
Solar Eclipse ◽  
Total Solar Eclipse ◽  
Electron Content ◽  
Total Electron

scholarly journals GPS-TEC observations over Nepal during the Total Solar Eclipse on 22 July 2009

2021 ◽  
Vol 7 (1) ◽  
pp. 54-59
Author(s):  
A. N. Shrestha ◽  
Y. Migoya-Orue
Keyword(s):  
Global Positioning System ◽  
Solar Eclipse ◽  
Total Solar Eclipse ◽  
Electron Content ◽  
Positioning System ◽  
Total Electron ◽  
Ionospheric Response ◽  
Gps Tec ◽  
Global Positioning ◽  
Geographical Locations

This paper explores the ionospheric response in terms of Total Electron Content (TEC) during the 22 July 2009 Total Solar Eclipse. Using the data stored at Biratnagar (BRN2), Ramite (RMTE), Dhangadhi (DNGD), Nepalganj (NPGJ), and Taplejung (TPLJ) Global Positioning System (GPS) stations, the ionospheric activity was investigated through changes in TEC. Our research is based on GPS-TEC measurements from a widely dispersed GPS network across various geographical locations in Nepal, taking place on July 17-21 as a pre-event, July 22 as the main event, and July 23-27 as a post-event. The analysis reveals that the reduction in the TEC level is proportional to the magnitude of the total solar eclipse. The variation of the TEC depends on latitude as well as longitude. We found that TEC depletion was up to 5% from pre-event to main-event and up to 30% from main-event to post-event during the totality of the eclipse. The eclipse was accompanied by the 10-hour geomagnetic storm in Nepal, which was the explanation for the TEC upgrade to 50% on the main event day from pre-event and decreased by 25% from main-event to post-event. The result obtained in this work demonstrates the influence of the eclipse/storm on the variation of TEC.

scholarly journals Decrease of total electron content during the 9 March 2016 total solar eclipse observed at low latitude stations, Indonesia

2019 ◽  
Author(s):  
Wahyu Srigutomo ◽  
Alamta Singarimbun ◽  
Winda Meutia ◽  
I Gede Putu Fadjar Soerya Djaja ◽  
Buldan Muslim ◽  
...  
Keyword(s):  
Solar Eclipse ◽  
Geographical Location ◽  
Total Solar Eclipse ◽  
Magnetic Equator ◽  
Initial Contact ◽  
Electron Content ◽  
Low Latitude ◽  
Total Electron ◽  
Photoionization Process ◽  
Time Required

Abstract. The total solar eclipse on 9 March 2016 was a rare phenomenon that could be observed in 12 provinces in Indonesia. The decline in solar radiation to the earth during a total solar eclipse affects the amount of electron content (TEC) in the ionosphere. The ionospheric dynamics during the eclipse above Indonesia have been studied using data from 40 GPS stations distributed throughout the archipelago. It was observed that TEC decrease occurred over Indonesia during the occurrence of the total eclipse. This TEC decrease did not instigate ionoshperic scintillation. Moreover, the relationship between eclipse magnitude and TEC decrease throughout three GPS stations was analysed using PRN 24 and PRN 12 codes. Data analysis from each station reveals that the time required by the TEC to achieve maximum reduction since the initial contact of the eclipse is faster than the recovery time. The maximum TEC reduction came about several minutes after the maximum obscuration indicating that the recombination process was still ongoing even though the peak of the eclipse had happened. The magnitude of this decline is positively correlated with the geographical location of the stations and the relative satellite trajectory with respect to the total solar eclipse trajectory. The amount of TEC reduction is proportional to the magnitude of the eclipse which is directly related to the photoionization process. Because Indonesia is located in a low latitude magnetic equator region, the dynamics of the ionosphere above it is more complex due to the fountain effect. During the solar eclipse, the fountain effect declines disturbing the plasma transport from the magnetic equator to low latitude regions.

scholarly journals Ionospheric perturbation during the South American total solar eclipse on 14th December 2020 revealed with the Chilean GPS eyeball

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mahesh N. Shrivastava ◽  
Ajeet Kumar Maurya ◽  
Kondapalli Niranjan Kumar
Keyword(s):  
Plasma Density ◽  
Solar Eclipse ◽  
Density Perturbation ◽  
Total Solar Eclipse ◽  
Electron Content ◽  
Vertical Total Electron Content ◽  
South American ◽  
The South ◽  
Total Electron ◽  
Atmospheric Gravity

AbstractThe influence of the South American total solar eclipse of 14th December 2020 on the ionosphere is studied by using the continuous Chilean Global Positioning System (GPS) sites across the totality path. The totality path with eclipse magnitude 1.012 passed through the Villarrica (Lon. 72.2308°W and Lat. 39.2820°S) in south Chile during 14:41:02.0 UTC to 17:30:58.1 UTC and maximum occurred ~ 16:03:49.5 UTC around the local noon. The vertical total electron content (VTEC) derived by GPS sites across the totality path for two PRN’s 29 and 31 show almost 20–40% of reduction with reference to ambient values. The percentage reduction was maximum close to totality site and decreases smoothly on both sides of totality sites. Interestingly, the atmospheric gravity waves (AGWs) with a period ~ 30–60 min obtained using wavelet analysis of VTEC timeseries show the presence of strong AGWs at the GPS sites located north of the totality line. But the AGWs do not show any significant effect on the VTEC values to these sites. Our analysis suggests, possibly an interplay between variability in the background plasma density and eclipse-generated AGWs induced plasma density perturbation could explain the observations.

scholarly journals Climatology of ionosphere over Nepal based on GPS total electron content data from 2008 to 2018

2021 ◽  
Vol 39 (4) ◽  
pp. 743-758
Author(s):  
Drabindra Pandit ◽  
Basudev Ghimire ◽  
Christine Amory-Mazaudier ◽  
Rolland Fleury ◽  
Narayan Prasad Chapagain ◽  
...  
Keyword(s):  
Solar Cycle ◽  
Total Electron Content ◽  
Solar Flux ◽  
Electron Content ◽  
Vertical Total Electron Content ◽  
Total Electron ◽  
Total Electron Content Data ◽  
Maximum Value ◽  
Spring Equinox ◽  
Cycle 24

Abstract. In this study, we analyse the climatology of ionosphere over Nepal based on GPS-derived vertical total electron content (VTEC) observed from four stations as defined in Table 1: KKN4 (27.80∘ N, 85.27∘ E), GRHI (27.95∘ N, 82.49∘ E), JMSM (28.80∘ N, 83.74∘ E) and DLPA (28.98∘ N, 82.81∘ E) during the years 2008 to 2018. The study illustrates the diurnal, monthly, annual, seasonal and solar cycle variations in VTEC during all times of solar cycle 24. The results clearly reveal the presence of equinoctial asymmetry in TEC, which is more pronounced in maximum phases of solar cycle in the year 2014 at KKN4 station, followed by descending, ascending and minimum phases. Diurnal variations in VTEC showed the short-lived day minimum which occurs between 05:00 to 06:00 LT (local time) at all the stations considered, with diurnal peaks between 12:00 and 15:00 LT. The maximum value of TEC is observed more often during the spring equinox than the autumn equinox, with a few asymmetries. Seasonal variation in TEC is observed to be a manifestation of variations in solar flux, particularly regarding the level of solar flux in consecutive solstices.

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