Ionospheric solar flare effects monitored by the ground‐based GPS receivers: Theory and observation

Abstract

[1] The ionosphere responses to a solar flare observed by using ground-based receivers of the global positioning system (GPS) are investigated in this paper. Two quantities, the total electron content (TEC) and its time rate of change (rTEC), can be derived from the receivers. The theoretical studies show that the rTEC is related to the frequency deviation of the GPS signals. Meanwhile, worldwide ground-based GPS receivers are employed to derive the TEC and associated rTEC to monitor the ionospheric solar flare effect on 14 July (Bastille Day) 2000. It is found that ionospheric solar flare effects can be observed from predawn to postdusk regions, and the most pronounced signatures appear in the midday area. The agreement between theoretical predications and observations demonstrates that the TEC is suitable to monitor the overall variations of flare radiations while the rTEC is capable to detect sudden changes in the flare radiations.

Summer‐winter hemispheric asymmetry of the sudden increase in ionospheric total electron content and of the O/N2 ratio: Solar activity dependence

“…Since the beginning of 21st century, the twodimensional imaging technique using TEC data from worldwide GPS receiver networks has been applied to SITEC studies [e.g., Afraimovich et al, 2001;Liu and Lin, 2004]. These studies have observed a solar zenith angle (SZA) dependence of SITEC [Zhang and Xiao, 2003;Wan et al, 2005].…”

Electrodynamical response of the Indian low-mid latitude ionosphere to the very large solar flare of 28 October 2003 – a case study

“…Saito et al (1998) have studied travelling ionospheric disturbances using GPS data. Liu et al (2004) investigated the ionospheric response to the solar flare of 14 July 2000 and they have shown that TEC is suitable to monitor the overall variations of flare radiations while its time rate of change aids the detection of sudden changes in the flare radiations. The enhancement of the horizontal component (H) of the geomagnetic field due to an X-ray flare event is called a Solar Flare effect (SFE).…”

The fast development of solar terrestrial sciences in Taiwan

“…The total electron content (TEC) in the global ionosphere map (GIM) routinely published allows us to monitor temporal SIPs at a specific location and discriminate the observed SIPs (Liu et al , 2010a) from global effects, such as solar flares, magnetic storms, and so on. (Liu et al 2004a). Statistical analyses for detecting both temporal and spatial precursors in the ionospheric TEC are developed (Liu et al 2004b(Liu et al , 2010b.…”