TEC

About: TEC is a research topic. Over the lifetime, 5119 publications have been published within this topic receiving 84696 citations.

Ionosphere response to solar wind high-speed streams

Abstract: [1] We present 9- and 7-day periodic oscillations in the global mean Total Electron Content (TEC) from 1 January 2005 to 31 December 2006. Spectral analysis indicates that the pronounced periodicities of 9 and 7 days observed in TEC are associated with variations in solar wind high-speed streams and geomagnetic activity. Neutral temperature and winds near 250 km, measured by a Fabry-Perot Interferometer at Resolute Bay, also exhibit 9- and 7-day periodicities. These pronounced periodicities support simultaneous observations of 9- and 7-day periodicities in thermosphere neutral density (Lei et al., 2008a; Thayer et al., 2008). It is anticipated that the ionospheric response at 9 and 7 days represents some combination of effects due to chemical loss, neutral winds, and disturbance dynamo-driven electric fields.

GPS global detection of the ionospheric response to solar flares

Abstract: This author suggests the concept of a new technology for global detection (GLOBDET) of atmospheric disturbances of natural and technogenic origin, on the basis of phase measurements of the total electron content (TEC) in the ionosphere using an international GPS network. Temporal dependencies of TEC are obtained for a set of spaced receivers of the GPS network simultaneously for the entire set of “visible” (over a given time interval) GPS satellites (up to 5–10 satellites). These series are subjected to filtering in the selected range of oscillation periods using algorithms for spatiotemporal analysis of signals of nonequidistant GPS phased antenna arrays which are adequate to the detected disturbance. An analysis is made of the possibilities of using the GLOBDET when detecting the ionospheric response of solar flares. In this case it is best to make the coherent summation of the filtered series of TEC. Powerful impulsive flares of July 29, 1999, and December 28, 1999, were chosen to illustrate the practical implementation of the proposed method.

Observations and simulations of seismoionospheric GPS total electron content anomalies before the 12 January 2010 M7 Haiti earthquake

Abstract: [1] In this paper, the total electron content (TEC) of the global ionosphere map (GIM) is used to detect seismoionospheric anomalies associated with the 12 January 2010 M7 Haiti earthquake, and an ionospheric model is applied to simulate the detected anomalies. The GIM temporal variation shows that the TEC over the epicenter significantly enhances on 11 January 2010, 1 day before the earthquake. The latitude-time-TEC (LTT) plots reveal three anomalies: (1) the northern crest of equatorial ionization anomaly (EIA) moves poleward, (2) the TECs at the epicenter and its conjugate increase, and (3) the TECs at two dense bands in the midlatitude ionosphere of 35°N and 60°S further enhance. The spatial analysis demonstrates that the TEC enhancement anomaly appears specifically and persistently in a small region of the northern epicenter area. The simulation well reproduces the three GIM TEC anomalies, which indicate that the dynamoelectric field of the ionospheric plasma fountain might have been perturbed by seismoelectric signals generated around the epicenter during the earthquake preparation period.