Dynamics of global electron content in 1998–2005 derived from global GPS data and IRI modeling

Astafyeva, Elvira; Afraimovich, É. L.; Oinats, Alexey; Yasukevich, Yu. V.; Zhivetiev, I. V.

doi:10.1016/j.asr.2007.11.007

Cited by 40 publications

(32 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In recent years, a database of ionospheric VTEC derived from GPS observations produced by a worldwide network of continuously tracking stations, has been used to investigate the local and regional characteristics of various anomalies (Huang and Cheng, 1996;Wu et al, 2004;Liu et al, 2009;Astafyeva et al, 2008). The worldwide GPS network above mentioned is managed by the International GNSS (Global Navigation Satellite System) Service, known as IGS.…”

Section: Introductionmentioning

confidence: 99%

Annual and semiannual variations of vertical total electron content during high solar activity based on GPS observations

Natali

Meza²

2011

Ann. Geophys.

View full text Add to dashboard Cite

Abstract. Annual, semiannual and seasonal variations of the Vertical Total Electron Content (VTEC) have been investigated during high solar activity in 2000. In this work we use Global IGS VTEC maps and Principal Component Analysis to study spatial and temporal ionospheric variability. The behavior of VTEC variations at two-hour periods, at noon and at night is analyzed. Particular characteristics associated with each period and the geomagnetic regions are highlighted.The variations at night are smaller than those obtained at noon. At noon it is possible to see patterns of the seasonal variation at high latitude, and patterns of the semiannual anomaly at low latitudes with a slow decrease towards mid latitudes. At night there is no evidence of seasonal or annual anomaly for any region, but it was possible to see the semiannual anomaly at low latitudes with a sudden decrease towards mid latitudes. In general, the semiannual behavior shows March-April equinox at least 40 % higher than September one. Similarities and differences are analyzed also with regard to the same analysis done for a period of low solar activity.

show abstract

Section: Introductionmentioning

confidence: 99%

Annual and semiannual variations of vertical total electron content during high solar activity based on GPS observations

Natali

Meza²

2011

Ann. Geophys.

View full text Add to dashboard Cite

show abstract

“…At the same time, the maximal deviations in the relative amplitude of 27-day GEC variations can exceed 20-30% (Astafyeva et al, 2007;Afraimovich et al, 2008). For the absolute TEC values of 20 TECU, this amounts to TEC changes within 10 TECU (or more) that is of a comparable amplitude with TEC "anomalies" reported before (Pulinets, 1998;Liu et al, 2001Liu et al, , 2004Pulinets et al, 2003;Pulinets and Boyarchuk, 2004;Zakharenkova et al, 2007).…”

Section: Estimation Of Global and Regional Tecmentioning

confidence: 57%

“…It should be noted that the accuracy of the estimation of the global mean TEC I (t) is higher than 0.5 TECU (Astafyeva et al, 2007), whereas that of the local mean TEC is less than 5 TECU. The estimations of TEC in each GIM cell are independent so, the relative error of GEC estimation is defined as…”

Section: Estimation Of Global and Regional Tecmentioning

confidence: 99%

“…For this purpose, we calculate global electron content (GEC) that is equal to the total number of electrons in the near-Earth space environment within the GPS orbital altitude of about 20,200 km (Afraimovich et al, 2006(Afraimovich et al, , 2008Astafyeva et al, 2007). Therefore, such an approach allows us to track the dynamics of global ionosphere.…”

Section: Estimation Of Global and Regional Tecmentioning

confidence: 99%

See 1 more Smart Citation

TEC anomalies—Local TEC changes prior to earthquakes or TEC response to solar and geomagnetic activity changes?

Afraimovich

Astafyeva

2008

Earth Planet Sp

View full text Add to dashboard Cite

A number of papers have reported on deviations of daily values of the maximum electron concentration of the ionospheric F 2 layer and/or total electron content (TEC) in the vicinity of an earthquake's epicenter some time prior to the quake. Owing to the importance of this problem, a question of a "locality" of those effects is emerging. To study this issue we have developed a method based on the calculation of global electron content and of local electron content in "check-region" with low seismic activity. The effect of TEC day-to-day changes before strong earthquakes is analyzed in this work. It is shown that in some cases this effect might be a reflection of global changes of the ionization caused by the 27-day variations as well as other fast alterations due to solar and geomagnetic activity changes. We discuss the problem of certain data corrections that permit local changes to be distinguished from global ones.

show abstract

“…Some new parameters, such as the Global Electron Content (GEC) Astafyeva et al, 2008) and the global mean TEC (Hocke, 2008(Hocke, , 2009, have also been derived to track the global characteristics of ionospheric dynamics. It is shown that there are annual variations, semiannual variations and regional variations in terms of TEC, and there is a strong dependence on the solar and geomagnetic activities for the TEC.…”

Section: Introductionmentioning

confidence: 99%

Variations of the ionospheric TEC using simultaneous measurements from the China Crustal Movement Observation Network

Liu

Zhang

et al. 2012

Ann. Geophys.

View full text Add to dashboard Cite

Abstract.Variations of the ionospheric Total Electron Content (TEC) over China are investigated using the TEC data obtained from China Crustal Movement Observation Network in the year 2004. The results show a single-peak occurred in post-noon for the diurnal variation and two peaks exit around two equinox points, respectively, for the seasonal variation. Overall, the values of TEC increased from the north to the south of China. There were small but clear longitudinal differences in both sides of the longitudes with zero magnetic declination. The intensity of the day-to-day variation of TEC was not a monotonic change along the latitudes. It was usually weaker in the middle of China than that in the north or south. Comparing with the maximum F-layer electron density (NmF2) derived from the ionosonde stations in China, it is found that the day-to-day variation of TEC was less significant than that of NmF2, and that the northern crest of the equatorial anomaly identified from the NmF2 data can reach Guangzhou-region. While, the TEC crest was hardly observed in the same location. This is probably caused by the tilt of topside ionosphere near the northern anomaly crest region at lower latitudes.

show abstract

Dynamics of global electron content in 1998–2005 derived from global GPS data and IRI modeling

Cited by 40 publications

References 19 publications

Annual and semiannual variations of vertical total electron content during high solar activity based on GPS observations

Annual and semiannual variations of vertical total electron content during high solar activity based on GPS observations

TEC anomalies—Local TEC changes prior to earthquakes or TEC response to solar and geomagnetic activity changes?

Variations of the ionospheric TEC using simultaneous measurements from the China Crustal Movement Observation Network

Contact Info

Product

Resources

About