Observations of Low‐Latitude Traveling Ionospheric Disturbances by a 630.0‐nm Airglow Imager and the CHAMP Satellite Over Indonesia

2019 ◽  
Vol 124 (3) ◽  
pp. 2198-2212
Author(s):  
Aysegul Ceren Moral ◽  
Kazuo Shiokawa ◽  
Shin Suzuki ◽  
Huixin Liu ◽  
Yuichi Otsuka ◽  
...  
Keyword(s):  
Ionospheric Disturbances ◽  
Low Latitude ◽  
Champ Satellite ◽  
Traveling Ionospheric Disturbances

scholarly journals Statistical study of medium-scale traveling ionospheric disturbances in low-latitude ionosphere using an automatic algorithm

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Pin-Hsuan Cheng ◽  
Charles Lin ◽  
Yuichi Otsuka ◽  
Hanli Liu ◽  
Panthalingal Krishanunni Rajesh ◽  
...  
Keyword(s):  
Climate Model ◽  
Geomagnetic Latitude ◽  
Detection Algorithm ◽  
Support Vector ◽  
Electron Content ◽  
Ionospheric Disturbances ◽  
Low Latitude ◽  
Total Electron ◽  
Medium Scale ◽  
Traveling Ionospheric Disturbances

AbstractThis study investigates the medium-scale traveling ionospheric disturbances (MSTIDs) statistically at the low-latitude equatorial ionization anomaly (EIA) region in the northern hemisphere. We apply the automatic detection algorithm including the three-dimensional fast Fourier transform (3-D FFT) and support vector machine (SVM) on total electron content (TEC) observations, derived from a network of ground-based global navigation satellite system (GNSS) receivers in Taiwan (14.5° N geomagnetic latitude; 32.5° inclination), to identify MSTID from other waves or irregularity features. The obtained results are analyzed statistically to examine the behavior of low-latitude MSTIDs. Statistical results indicate the following characteristics. First, the southward (equatorward) MSTIDs are observed almost every day during 0800–2100 LT in Spring and Winter. At midnight, southward MSTIDs are more discernible in Summer and majority of them are propagating from Japan to Taiwan. Second, northward (poleward) MSTIDs are more frequently detected during 1200–2100 LT in Spring and Summer with the secondary peak of occurrence between day of year (DOY) 100–140 during 0000–0300 LT. The characteristics of the MSTIDs are interpreted with additional observations from radio occultation (RO) soundings of FORMOSAT-3/COSMIC as well as modeled atmospheric waves from the high-resolution Whole Atmosphere Community Climate Model (WACCM) suggesting that the nighttime MSTIDs in Summer is likely connected to the atmospheric gravity waves (AGWs).

Numerical Modeling of the Concentric Gravity Wave Seeding of Low-Latitude Nighttime Medium-Scale Traveling Ionospheric Disturbances

2018 ◽  
Vol 45 (13) ◽  
pp. 6390-6399 ◽  
Author(s):  
Min-Yang Chou ◽  
Charles C. H. Lin ◽  
Joseph D. Huba ◽  
Chuan-Ping Lien ◽  
Chia-Hung Chen ◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Gravity Wave ◽  
Ionospheric Disturbances ◽  
Low Latitude ◽  
Medium Scale ◽  
Traveling Ionospheric Disturbances

scholarly journals Statistical Study of Medium-Scale Traveling Ionospheric Disturbances in Low-Latitude Ionosphere Using an Automatic Algorithm

2020 ◽  
Author(s):  
PinHsuan Cheng ◽  
Charles Lin ◽  
Yuichi Otsuka ◽  
Hanli Liu ◽  
Panthalingal Krishanunni Rajesh ◽  
...  
Keyword(s):  
Climate Model ◽  
Geomagnetic Latitude ◽  
Detection Algorithm ◽  
Support Vector ◽  
Electron Content ◽  
Ionospheric Disturbances ◽  
Low Latitude ◽  
Total Electron ◽  
Medium Scale ◽  
Traveling Ionospheric Disturbances

Abstract This study investigates the medium–scale traveling ionospheric disturbances (MSTIDs) statistically at the low–latitude equatorial ionization anomaly (EIA) region in the northern hemisphere. We apply the automatic detection algorithm including the three-dimensional fast Fourier transform (3-D FFT) and support vector machine (SVM) on total electron content (TEC) observations, derived from a network of ground-based global navigation satellite system (GNSS) receivers in Taiwan (14.5°N geomagnetic latitude; 32.5° inclination), to identify MSTID from other waves or irregularity features. The obtained results are analyzed statistically to examine the behavior of low-latitude MSTIDs. Statistical results indicate the following characteristics. First, the southward (equatorward) MSTIDs are observed almost every day during 0800-2100 LT in Spring and Winter. At midnight, southward MSTIDs are more discernible in Summer and majority of them are propagating from Japan to Taiwan. Second, northward (poleward) MSTIDs are more frequently detected during 1200-2100 LT in Spring and Summer with the secondary peak of occurrence between day of year (DOY) 100-140. The characteristics of the MSTIDs are interpreted with additional observations from radio occultation (RO) soundings of FORMOSAT-3/COSMIC as well as modeled atmospheric waves from the high–resolution Whole Atmosphere Community Climate Model (WACCM) suggesting that the nighttime MSTIDs in Summer is likely connected to the atmospheric gravity waves (AGWs).

Characteristics of daytime medium scale traveling ionospheric disturbances (MSTIDs) as observed by SWARM

2020 ◽  
Author(s):  
Chinmaya Nayak ◽  
Stephan Buchert
Keyword(s):  
Electron Density ◽  
Ionospheric Disturbances ◽  
Magnetic Fluctuations ◽  
Low Latitude ◽  
Plasma Irregularities ◽  
Medium Scale ◽  
Traveling Ionospheric Disturbances ◽  
Spatio Temporal ◽  
Low Latitude Ionosphere ◽  
Rule Out

<p><span>This paper studies the daytime medium scale traveling ionospheric disturbances (MSTIDs) in the mid- and low-latitude ionosphere for a period of nearly half a solar cycle (2014-2019) using SWARM observations. We specifically focus on daytime MSTIDs to rule out any contribution from nighttime plasma irregularities. Fluctuations in electron density are primarily used to identify the MSTIDs. These wave like structures are independently observed in both electron density and magnetic fluctuations, although they do not always show one to one correlation. In most cases, the structures are observed by both satellite ‘A’ and ‘C’, suggesting that their zonal extent is more than 140 km. The study makes an attempt to understand and explain the magnetic conjugate nature of the MSTIDs. To have a better understanding of the dynamics of the MSTIDs, ground based GPS-TEC and ionosonde data has been used on case to case basis, wherever available. Additionally, spatio-temporal statistics of MSTID distribution is presented. </span></p>

scholarly journals Characterization of medium-scale traveling ionospheric disturbances in the brazilian low latitude sector – Statistical Analysis of All-Sky Images of oi 630 nm airglow emission

2012 ◽  
Vol 30 (2) ◽  
Author(s):  
Danielle Cristina de Morais Amorim ◽  
Alexandre Alvares Pimenta ◽  
Aline Amorim de Almeida
Keyword(s):  
Statistical Analysis ◽  
Maximum Activity ◽  
Occurrence Rate ◽  
Ionospheric Disturbances ◽  
Low Latitude ◽  
Medium Scale ◽  
Airglow Emission ◽  
Traveling Ionospheric Disturbances ◽  
A Minor

In order to characterize the phenomenon known as Medium-Scale Traveling Ionospheric Disturbances (MSTIDs), we present in this paper the resultsobtained from the statistical analysis of 10.5 years all-sky images of OI 630 nm airglow emission over the Brazilian low latitude sector. The images, which were obtainedby an all-sky imager installed at Cachoeira Paulista (22.7◦S, 45◦W), show dark band structures propagating from southeast to northwest with velocities of 50-200 m/s.Our results show the greatest occurrence of MSTIDs during solar minimum and a minor occurrence rate during descending and ascending solar activity periods. Duringsolar maximum activity we have not detected MSTIDs signatures on all-sky images. In relation to seasonality, the greatest frequency of occurrence is during local winter.All detected events have occurred during geomagnetically quiet conditions (Kp<3). Possible mechanisms of generation of this phenomenon are discussed.

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