scholarly journals GNSS Ionosphere Sounding of Equatorial Plasma Bubbles

Atmosphere ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 676
Author(s):  
Guanyi Ma ◽  
Klemens Hocke ◽  
Jinghua Li ◽  
Qingtao Wan ◽  
Weijun Lu ◽  
...  
Keyword(s):  
Satellite System ◽  
Low Earth Orbit ◽  
Occurrence Rate ◽  
Scintillation Index ◽  
Electron Content ◽  
Total Electron ◽  
Plasma Bubbles ◽  
Equatorial Plasma Bubbles ◽  
Gnss Receivers ◽  
Gnss Data

Ground- and space-based Global Navigation Satellite System (GNSS) receivers can provide three-dimensional (3D) information about the occurrence of equatorial plasma bubbles (EPBs). For this study, we selected March 2014 data (during solar maximum of cycle 24) for the analysis. The timing and the latitudinal dependence of the EPBs occurrence rate are derived by means of the rate of the total electron content (TEC) index (ROTI) data from GNSS receivers in China, whereas vertical profiles of the scintillation index S4 are provided by COSMIC (Constellation Observing System for Meteorology, Ionosphere and Climate). The GNSS receivers of the low Earth orbit satellites give information about the occurrence of amplitude scintillations in limb sounding geometry where the focus is on magnetic latitudes from 20° S to 20° N. The occurrence rates of the observed EPB-induced scintillations are generally smaller than those of the EPB-induced ROTI variations. The timing and the latitude dependence of the EPBs occurrence rate agree between the ground-based and spaceborne GNSS data. We find that EPBs occur at 19:00 LT and they are mainly situated above the F2 peak layer which descended from 450 km at 20:00 LT to 300 km at 24:00 LT in the equatorial ionosphere. At the same time, the spaceborne GNSS data also show, for the first time, a high occurrence rate of post-sunset scintillations at 100 km altitude, indicating the coexistence of equatorial sporadic E with EPBs.

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 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 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)

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 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 Characteristics of ionospheric irregularities near the northern equatorial anomaly crest

2019 ◽  
Author(s):  
Jinghua Li ◽  
Guanyi Ma ◽  
Klemens Hocke ◽  
Qingtao Wan ◽  
Jiangtao Fan ◽  
...  
Keyword(s):  
Seasonal Variations ◽  
Ionospheric Irregularities ◽  
Lower Latitude ◽  
Occurrence Rate ◽  
Electron Content ◽  
Plasma Bubble ◽  
Equatorial Anomaly ◽  
Total Electron ◽  
Latitude Belt ◽  
Plasma Bubbles

Abstract. This paper detects the ionospheric irregularities with rate of total electron content (TEC) change index, ROTI from GPS observation at Taoyuan (24.95° N, 121.16° E) for the solar medium and minimum years of 2003 and 2008 in the declining phase of cycle 23, the solar maximum of 2014 in solar cycle 24. Local occurrence rate (LOR) is proposed to clarify the characteristics of the irregularities together with monthly occurrence rate (MOR) and ROTI maximum for 3 latitude belts, 20–23° N, 23–26° N, 26–29° N, around the equatorial anomaly crest. MOR in May/June is larger than those in equinoxes in 2008 and 2003, which is different from that of equatorial plasma bubbles. In 2014 although MOR maximum is observed in equinoxes, the MOR in May and June is much larger than that in September. Moreover, MORs in May to August at higher latitude belt 26–29° N are larger than those in lower latitude belts and smaller in the equinoxes. The latitudinal dependence of the LORs tends to be similar to that of MORs. Seasonal variations of LORs have a similar trend for different solar activities. Maximum LORs are observed in Feb/Mar and Sep/Oct, and moderate around June, which resemble those of plasma bubbles in seasonal variations, except for latitude belt 26–29° N where maximum LORs are seen in May–Jul. The seasonal variation of ROTI maximum conforms to that of the LOR. The results suggest that irregularities near the crest in May to August are mainly originated from nonequatorial process, which is more frequently happened but weaker than plasma bubble in both spatiotemporal scale and strength.

A New Approach to Monitoring the Interplanetary Shock Induced Pulse: TEC Measurements by the GNSS Receiver Network

2020 ◽  
Author(s):  
Xingran Chen ◽  
Quanhan Li ◽  
Qiugang Zong ◽  
Yongqiang Hao
Keyword(s):  
Propagation Speed ◽  
Interplanetary Shock ◽  
Satellite System ◽  
Wave Form ◽  
Electron Content ◽  
Shock Pulse ◽  
Total Electron ◽  
New Approach ◽  
Gnss Receivers ◽  
Global Navigation Satellite

<p>We revisit the typical interplanetary shock event on November 7, 2004, with high resolution total electron content (TEC) measurements obtained by the distributed Global Navigation Satellite System (GNSS) receivers. TEC impulses were observed after the IP shock impinged on the dayside agnetosphere at ~18:27 UT. In view of the similarity of the wave form and the time-delay characteristics, the TEC impulses were regarded as responses to the IP shock, despite the small amplitude (in the order of 0.4 TECU). Particularly, the peak of the TEC impulse was first observed by the receivers located around 120°W geographic longitude (corresponding to noon magnetic local time), while receivers at both sides recorded the impulse sequentially afterwards. From the timedelay of the TEC impulse, we derive the propagation velocity of the shock induced pulse. The angular velocity of the pulse is estimated to be ~2 degree per second, which is in the same order as the propagation speed of a typical shock pulse in the magnetosphere. Our results present global observational features of the shock pulse and provide new aspects to understand the ionospheric-magnetospheric dynamics in response to IP shocks.</p>

scholarly journals Correlation between Ionospheric TEC and the DCB Stability of GNSS Receivers from 2014 to 2016

2019 ◽  
Vol 11 (22) ◽  
pp. 2657 ◽  
Author(s):  
Choi ◽  
Sohn ◽  
Lee
Keyword(s):  
Estimation Method ◽  
Satellite System ◽  
Electron Content ◽  
Strong Positive Correlation ◽  
Low Latitude ◽  
Total Electron ◽  
Gnss Receiver ◽  
Gnss Receivers ◽  
Global Navigation Satellite ◽  
The Relationship

The Global Navigation Satellite System (GNSS) differential code biases (DCBs) are a major obstacle in estimating the ionospheric total electron content (TEC). The DCBs of the GNSS receiver (rDCBs) are affected by various factors such as data quality, estimation method, receiver type, hardware temperature, and antenna characteristics. This study investigates the relationship between TEC and rDCB, and TEC and rDCB stability during a three-year period from 2014 to 2016. Linear correlations between pairs of variables, measured with Pearson’s coefficient (), are considered. It is shown that the correlation between TEC and rDCB is the smallest in low-latitude regions. The mid-latitude regions exhibit the maximum value of. In contrast, the correlation between TEC and rDCB root mean square (RMS, stability) was greater in low-latitude regions. A strong positive correlation (R≥0.90) on average between TEC and rDCB RMS was also revealed at two additional GNSS stations in low-latitude regions, where the correlation shows clear latitudinal dependency. We found that the correlation between TEC and rDCB stability is still very strong even after replacing a GNSS receiver.

scholarly journals Comparison of volcanic explosions in Japan using impulsive ionospheric disturbances

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Mokhamad Nur Cahyadi ◽  
Eko Yuli Handoko ◽  
Ririn Wuri Rahayu ◽  
Kosuke Heki
Keyword(s):  
Wave Speed ◽  
Volcanic Eruptions ◽  
Satellite System ◽  
Electron Content ◽  
Total Electron ◽  
F Region ◽  
Gnss Receivers ◽  
Explosive Volcanic Eruptions ◽  
Global Navigation Satellite ◽  
Volcanic Explosions

AbstractUsing the ionospheric total electron content (TEC) data from ground-based Global Navigation Satellite System (GNSS) receivers in Japan, we compared ionospheric responses to five explosive volcanic eruptions 2004–2015 of the Asama, Shin-Moe, Sakurajima, and Kuchinoerabu-jima volcanoes. The TEC records show N-shaped disturbances with a period ~ 80 s propagating outward with the acoustic wave speed in the F region of the ionosphere. The amplitudes of these TEC disturbances are a few percent of the background absolute vertical TEC. We propose to use such relative amplitudes as a new index for the intensity of volcanic explosions. Graphical Abstract

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