scholarly journals DETECTION OF EQUATORIAL PLASMA BUBBLES USING GPS IONOSPHERIC TOMOGRAPHY OVER PENINSULAR MALAYSIA

2021 ◽  
Vol 6 (24) ◽  
pp. 152-160
Author(s):  
Siti Syukriah Khamdan ◽  
Tajul Ariffin Musa ◽  
Suhaila M. Buhari
Keyword(s):  
Three Dimensional ◽  
Peninsular Malaysia ◽  
Rate Of Change ◽  
Electron Content ◽  
Total Electron ◽  
Ionospheric Tomography ◽  
Plasma Bubbles ◽  
Equatorial Plasma Bubbles ◽  
Tomography Method

This paper presents the detection of the equatorial plasma bubbles (EPB) using the Global Positioning System (GPS) ionospheric tomography method over Peninsular Malaysia. This paper aims to investigate the capability of the GPS ionospheric tomography method in detecting the variations of the EPB over the study area. In doing so, a previous case study during post-sunset 5th April 2011 has been selected as a reference for the detection of the EPBs over the study area. It has been observed that at least three structures of the EPBs have been captured based on the rate of change total electron content (TEC) index (ROTI) from 12 UT until 19 UT. Therefore, the three-dimensional ionospheric profiles have been reconstructed over Peninsular Malaysia using the tomography method during the study period in order to capture the signature of the EPBs. In this study, the detection of the EPBs using the tomography method is based on the rate of change of electron density (ROTNe). The results from three-dimensional ionospheric tomography show only two structures of EPBs are detected during the study period. It has been observed that the ROTNe depleted up to ~-12x109el/cm. Overall, the results in this study show that the GPS ionospheric tomography capable to be utilized in detecting the variations of EPBs in support of ionospheric studies and monitoring in the Malaysian region.

scholarly journals Three-dimensional morphology of equatorial plasma bubbles deduced from measurements onboard CHAMP

2015 ◽  
Vol 33 (1) ◽  
pp. 129-135 ◽  
Author(s):  
J. Park ◽  
H. Lühr ◽  
M. Noja
Keyword(s):  
Three Dimensional ◽  
Satellite System ◽  
Low Earth Orbit ◽  
Electron Content ◽  
Total Electron ◽  
Plasma Bubbles ◽  
Equatorial Plasma Bubbles ◽  
Global Navigation Satellite ◽  
Plasma Depletion

Abstract. Total electron content (TEC) between Low-Earth-Orbit (LEO) satellites and the Global Navigation Satellite System (GNSS) satellites can be used to constrain the three-dimensional morphology of equatorial plasma bubbles (EPBs). In this study we investigate TEC measured onboard the Challenging Minisatellite Payload (CHAMP) from 2001 to 2005. We only use TEC data obtained when CHAMP passed through EPBs: that is, when in situ plasma density measurements at CHAMP altitude also show EPB signatures. The observed TEC gradient along the CHAMP track is strongest when the corresponding GNSS satellite is located equatorward and westward of CHAMP with elevation angles of about 40–60°. These elevation and azimuth angles are in agreement with the angles expected from the morphology of the plasma depletion shell proposed by Kil et al.(2009).

scholarly journals Occurrence characteristics of equatorial plasma bubbles over Kisumu, Kenya during Solar maximum of Solar Cycle 24

2021 ◽  
Vol 9 (1) ◽  
pp. 1
Author(s):  
Edward Nyongesa ◽  
Ndinya Boniface ◽  
Omondi George
Keyword(s):  
Solar Cycle ◽  
Rate Of Change ◽  
Electron Content ◽  
Quiet Period ◽  
Total Electron ◽  
Plasma Bubbles ◽  
Equatorial Plasma Bubbles ◽  
Solar Cycle 24 ◽  
Cycle 24 ◽  
Year 2013

Equatorial Plasma Bubbles (EPBs) are irregular plasma density depletions in the ambient electron density in the equatorial F-region ionosphere generated after sunset. EPBs are known to bring disruptions to telecommunication and navigation systems. This paper investigates the occurrence of EPBs over Kisumu, Kenya (Geomagnetic coordinates: 9.64o S, 108.59o E; Geographic coordinates: 0.02o S, 34.6o E) for a few selected quiet and storm days between 1st January 2013 and 31st December 2014 which was a high Solar activity period for Solar Cycle 24. The study brings out EPB occurrence pattern over Kisumu, Kenya for the selected quiet and storm days of 2013 and 2014. The Receiver Independent Exchange (RINEX) data was retrieved from the Kisumu high data-rate NovAtel GSV4004B SCINDA-GPS receiver. The data was unzipped and processed to obtain Vertical Total Electron Content (VTEC), amplitude scintillation (S4) and Universal Time (UT) which were then fed into MATLAB to generate VTEC and S4 plots against UT for each selected quiet and storm day within the years 2013 and 2014. The Total Electron Content (TEC) depletion depths and S4 index values between 16:00 and 20:00 UT for each selected quiet and storm day were extracted from the VTEC and S4 plots and used to plot TEC depletion depths and S4 plots. The Rate of Change of TEC (ROT) and Rate of Change of TEC Index (ROTI) between 16:00 and 20:00 UT were generated from VTEC and used to plot ROT and the corresponding ROTI plots against UT. TEC depletion depths and ROTI values for each selected quiet and storm day between 16:00 and 20:00 UT were extracted and used to plot TEC depletion depths and ROTI plots and S4 index and ROTI plots. In this study, the enhancement of S4 index corresponded well with TEC depletions, increased fluctuation of ROT and higher ROTI values between 16:00UT and 20:00UT for most days. This correspondence was used in inferring the occurrence of EPBs during the selected quiet and storm days of the years 2013 and 2014. The obtained results showed that the highest EPB occurrence was during March equinox with 33.33% occurrence in the year 2013 and 30.76% occurrence in the year 2014, followed by the September equinox which had 20.38% occurrence in 2013 and 17.26% occurrence in 2014. The seasonal variation of EPB occurrence was attributed to the variation in the daytime E x B drift velocities. Larger E x B drift velocities resulted in increased EPB occurrence in the equinoctial period (March, April, August and September) and November solstice period (November and December) while lower E x B drift velocities resulted in reduced EPB occurrence in the June solstice period (June and July). The percentage EPB occurrence in the year 2013 was 6.49% while in the year 2014 was 4.32%. The storm period had percentage EPB occurrence of 21.42% in the year 2013 and 21.88% in the year 2014 while the quiet period had percentage EPB occurrence of 18.75% in the year 2013 and 7.89% in the year 2014. These results clearly showed that the percentage EPB occurrence was higher during the storm period than in the quiet period. Hence the development of EPBs was enhanced by geomagnetic activity through several competing dynamics such as Prompt Penetration Electric Field (PPEF), Disturbance Dynamo Electric Field (DDEF) and reduction in electron density due to increased recombination rates.  

scholarly journals Study of Equatorial Plasma Bubbles Using ASI and GPS Systems

2020 ◽  
Author(s):  
Dada P. Nade ◽  
Swapnil S. Potdar ◽  
Rani P. Pawar
Keyword(s):  
Electron Content ◽  
Gps Receiver ◽  
Plasma Bubble ◽  
Low Latitude ◽  
Total Electron ◽  
Plasma Irregularities ◽  
Plasma Bubbles ◽  
F Region ◽  
Equatorial Plasma Bubbles ◽  
Background Density

The plasma irregularities have been frequently observed in the F-region, at low latitude regions, due to the instability processes occurring in the ionosphere. The depletions in electron density, as compared to the background density, is a signature of the plasma irregularities. These irregularities are also known as the “equatorial plasma bubble” (EPB). These EPBs can measure by the total electron content (TEC) using GPS receiver and by images of the nightglow OI 630.0 nm emissions using all sky imager (ASI). The current chapter is based on the review on the signature of the EPBs in TEC and ASI. measurements. We have also discussed the importance of the study of EPBs.

scholarly journals A ROTI-Aided Equatorial Plasma Bubbles Detection Method

2021 ◽  
Vol 13 (21) ◽  
pp. 4356
Author(s):  
Long Tang ◽  
Osei-Poku Louis ◽  
Wu Chen ◽  
Mingli Chen
Keyword(s):  
Hong Kong ◽  
Total Electron Content ◽  
Detection Method ◽  
Temporal Distribution ◽  
Satellite System ◽  
Previous Method ◽  
Electron Content ◽  
Total Electron ◽  
Plasma Bubbles ◽  
Equatorial Plasma Bubbles

In this study, we present a Rate of Total Electron Content Index (ROTI)-aided equatorial plasma bubbles (EPBs) detection method based on a Global Navigation Satellite System (GNSS) ionospheric Total Electron Content (TEC). This technique seeks the EPBs occurrence time according to the ROTI values and then extracts the detrended ionospheric TEC series, which include EPBs signals using a low-order, partial polynomial fitting strategy. The EPBs over the Hong Kong area during the year of 2014 were detected using this technique. The results show that the temporal distribution and occurrence of EPBs over the Hong Kong area are consistent with that of previous reports, and most of the TEC depletion error is smaller than 1.5 TECU (average is 0.63 TECU), suggesting that the detection method is feasible and highly accurate. Furthermore, this technique can extract the TEC depletion series more effectively, especially for those with a long duration, compared to previous method.

scholarly journals Identification of potential precursors for the occurrence of Large-Scale Traveling Ionospheric Disturbances in a case study during September 2017

2020 ◽  
Vol 10 ◽  
pp. 32
Author(s):  
Arthur Amaral Ferreira ◽  
Claudia Borries ◽  
Chao Xiong ◽  
Renato Alves Borges ◽  
Jens Mielich ◽  
...  
Keyword(s):  
Real Time ◽  
Electron Density ◽  
Large Scale ◽  
Rate Of Change ◽  
Electron Content ◽  
Ionospheric Disturbances ◽  
Total Electron ◽  
Traveling Ionospheric Disturbances ◽  
Auroral Activity

Traveling Ionospheric Disturbances (TIDs) reflect changes in the ionospheric electron density which are caused by atmospheric gravity waves. These changes in the electron density impact the functionality of different applications such as precise navigation and high-frequency geolocation. The Horizon 2020 project TechTIDE establishes a warning system for the occurrence of TIDs with the motivation to mitigate their impact on communication and navigation applications. This requires the identification of appropriate indicators for the generation of TIDs and for this purpose we investigate potential precursors for the TID occurrence. This paper presents a case study of the double main phase geomagnetic storm, starting from the night of 7th September and lasting until the end of 8th September 2017. Detrended Total Electron Content (TEC) derived from Global Navigation Satellite System (GNSS) measurements from more than 880 ground stations in Europe was used to identify the occurrence of different types of large scale traveling ionospheric disturbances (LSTIDs) propagating over the European sector. In this case study, LSTIDs were observed more frequently and with higher amplitude during periods of enhanced auroral activity, as indicated by increased electrojet index (IE) from the International Monitor for Auroral Geomagnetic Effects (IMAGE). Our investigation suggests that Joule heating due to the dissipation of Pedersen currents is the main contributor to the excitation of the observed LSTIDs. We observe that the LSTIDs are excited predominantly after strong ionospheric perturbations at high-latitudes. Ionospheric parameters including TEC gradients, the Along Arc TEC Rate (AATR) index and the Rate Of change of TEC index (ROTI) have been analysed for their suitability to serve as a precursor for LSTID occurrence in mid-latitude Europe, aiming for near real-time indication and warning of LSTID activity. The results of the presented case study suggest that the AATR index and TEC gradients are promising candidates for near real-time indication and warning of the LSTIDs occurrence in mid-latitude Europe since they have a close relation to the source mechanisms of LSTIDs during periods of increased auroral activity.

scholarly journals Characteristics of equatorial plasma bubbles observed by TEC map based on ground-based GNSS receivers over South America

2018 ◽  
Vol 36 (1) ◽  
pp. 91-100 ◽  
Author(s):  
Diego Barros ◽  
Hisao Takahashi ◽  
Cristiano M. Wrasse ◽  
Cosme Alexandre O. B. Figueiredo
Keyword(s):  
Drift Velocity ◽  
Latitudinal Gradient ◽  
Onset Time ◽  
Electron Content ◽  
Total Electron ◽  
Plasma Bubbles ◽  
Equatorial Plasma Bubbles ◽  
Gnss Receivers ◽  
The Difference ◽  
Field Lines

Abstract. A ground-based network of GNSS receivers has been used to monitor equatorial plasma bubbles (EPBs) by mapping the total electron content (TEC map). The large coverage of the TEC map allowed us to monitor several EPBs simultaneously and get characteristics of the dynamics, extension and longitudinal distributions of the EPBs from the onset time until their disappearance. These characteristics were obtained by using TEC map analysis and the keogram technique. TEC map databases analyzed were for the period between November 2012 and January 2016. The zonal drift velocities of the EPBs showed a clear latitudinal gradient varying from 123 m s−1 at the Equator to 65 m s−1 for 35∘ S latitude. Consequently, observed EPBs are inclined against the geomagnetic field lines. Both zonal drift velocity and the inclination of the EPBs were compared to the thermospheric neutral wind, which showed good agreement. Moreover, the large two-dimensional coverage of TEC maps allowed us to study periodic EPBs with a wide longitudinal distance. The averaged values observed for the inter-bubble distances also presented a clear latitudinal gradient varying from 920 km at the Equator to 640 km at 30∘ S. The latitudinal gradient in the inter-bubble distances seems to be related to the difference in the zonal drift velocity of the EPB from the Equator to middle latitudes and to the difference in the westward movement of the terminator. On several occasions, the distances reached more than 2000 km. Inter-bubble distances greater than 1000 km have not been reported in the literature. Keywords. Ionosphere (equatorial ionosphere; ionospheric irregularities) – meteorology and atmospheric dynamics (thermospheric dynamics)

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