scholarly journals Delayed traveling ionospheric disturbances, especially in equatorial regions, following geomagnetic activity

2003 ◽  
Vol 55 (8) ◽  
pp. 483-492
Author(s):  
G. G. Bowman ◽  
I. K. Mortimer
Keyword(s):  
Geomagnetic Activity ◽  
Ionospheric Disturbances ◽  
Traveling Ionospheric Disturbances

scholarly journals Geomagnetic control of the spectrum of traveling ionospheric disturbances based on data from a global GPS network

2001 ◽  
Vol 19 (7) ◽  
pp. 723-731 ◽  
Author(s):  
E. L. Afraimovich ◽  
E. A. Kosogorov ◽  
O. S. Lesyuta ◽  
I. I. Ushakov ◽  
A. F. Yakovets
Keyword(s):  
Geomagnetic Activity ◽  
Time Derivative ◽  
Power Spectra ◽  
Small Scale ◽  
Electron Content ◽  
Ionospheric Disturbances ◽  
Geomagnetic Disturbances ◽  
Absolute Level ◽  
Total Electron ◽  
Traveling Ionospheric Disturbances

Abstract. In this paper an attempt is made to verify the hypothesis of the role of geomagnetic disturbances as a factor in determining the intensity of traveling ionospheric disturbances (TIDs). To improve the statistical validity of the data, we have used the method involving a global spatial averaging of disturbance spectra of the total electron content (TEC). To characterize the TID intensity quantitatively, we suggest that a new global index of the degree of disturbance should be used, which is equal to the mean value of the rms variations in TEC within the selected range of spectral periods (of 20– 60 min, in the present case). The analysis has been made for a set of 100 to 300 GPS stations for 10 days with a different level of geomagnetic activity (Dst from 0 to –350 nT; the Kp index from 3 to 9). It was found that power spectra of daytime TEC variations in the range of 20–60 min periods under quiet conditions have a power-law form with the slope index k = –2.5. With an increase in the level of magnetic disturbance, there is an increase in the total intensity of TIDs, with a concurrent kink of the spectrum caused by an increase in oscillation intensity in the range of 20–60 min. The TEC variation amplitude is found to be smaller at night than during the daytime, and the spectrum decreases in slope, which is indicative of a disproportionate increase in the amplitude of the small-scale part of the spectrum. It was found that an increase in the level of geomagnetic activity is accompanied by an increase in the total intensity of TEC; however, it does not correlate with the absolute level of Dst, but rather with the value of the time derivative of Dst (a maximum correlation coefficient reaches –0.94). The delay of the TID response of the order of 2 hours is consistent with the view that TIDs are generated in auroral regions, and propagate equatorward with the velocity of about 300–400 m/s.Key words. Ionosphere (ionospheric disturbances; auroral ionosphere; equatorial ionopshere)

scholarly journals Traveling ionospheric disturbances in the Weddell Sea Anomaly associated with geomagnetic activity

2013 ◽  
Vol 118 (10) ◽  
pp. 6608-6617 ◽  
Author(s):  
S. E. Milan ◽  
A. Grocott ◽  
S. de Larquier ◽  
M. Lester ◽  
T. K. Yeoman ◽  
...  
Keyword(s):  
Geomagnetic Activity ◽  
Weddell Sea ◽  
Ionospheric Disturbances ◽  
Traveling Ionospheric Disturbances ◽  
Weddell Sea Anomaly

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).

scholarly journals Direct Observations of Traveling Ionospheric Disturbances as Focusers of Solar Radiation: Spectral Caustics

2019 ◽  
Vol 877 (2) ◽  
pp. 98
Author(s):  
Artem Koval ◽  
Yao Chen ◽  
Takuya Tsugawa ◽  
Yuichi Otsuka ◽  
Atsuki Shinbori ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Ionospheric Disturbances ◽  
Traveling Ionospheric Disturbances ◽  
Direct Observations

Analysis of traveling ionospheric disturbances (TIDs) in GPS TEC launched by the 2011 Tohoku earthquake

Radio Science ◽  
2016 ◽  
Vol 51 (5) ◽  
pp. 507-514 ◽  
Author(s):  
Geoff Crowley ◽  
Irfan Azeem ◽  
Adam Reynolds ◽  
Timothy M. Duly ◽  
Patrick McBride ◽  
...  
Keyword(s):  
Tohoku Earthquake ◽  
2011 Tohoku Earthquake ◽  
Ionospheric Disturbances ◽  
The 2011 Tohoku Earthquake ◽  
Gps Tec ◽  
Traveling Ionospheric Disturbances
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