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

Abstract

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.

Ionospheric Response over Nepal during the 26 December 2019 Solar Eclipse

“…In particular, eclipse studies for the December 26, 2019 event have benefited from several early research work by Chandra et al (1997Chandra et al ( , 2007 [6,7], Sharma et al (2010) [4], Coster et al (2017) [8], for example, show decrease in electron density of ionosphere during the solar eclipses and coverage of groundbased monitoring GPS segments. GPS data were also used in many studies to analyze the TEC variation during the solar eclipse, e.g., Baran et al (2003) [9] accounted for the depression of TEC amounted to 2 -8 TECU during the solar eclipse of August 11, 1999. Srigutomo et al (2019 [10] has additionally shown that the rate of depletion of TEC is proportional to the magnitude of the eclipse, which is directly associated with the photoionization process.…”

“…GPS data were also used in many studies to analyze the TEC variation during the solar eclipse, e.g., Baran et al (2003) [9] accounted for the depression of TEC amounted to 2 -8 TECU during the solar eclipse of August 11, 1999. Srigutomo et al (2019 [10] has additionally shown that the rate of depletion of TEC is proportional to the magnitude of the eclipse, which is directly associated with the photoionization process.…”

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

“…The Fountain effect is achieved by the decrease in the E×B plasma drift at low latitudes, and the strength of the Fountain effect will weaken when a solar eclipse occurs. As a result, the electron transport process will also decrease at low latitudes, which induces a decrease in TEC value in the low latitude region [8,11]. And the longitude depends on local time, being equal to 1-hour local time with 15 o longitude.…”