Statistical study of large-scale traveling ionospheric disturbances generated by the solar terminator over China

摘要

This paper presents a statistical result of large-scale traveling ionospheric disturbances (LSTIDs) associated with moving solar terminator in China during 12 months from February 2011 to January 2012. The LSTIDs are identified by the two-dimensional total electron content (TEC) perturbation maps, which are built based on the observations of GPS network data from China. The GPS observations are combined with the observations from an ionosonde chain established by the Institute of Geology and Geophysics, Chinese Academy of Sciences. A total of 135 LSTID events are identified at dawn, while there is indiscernible LSTID at dusk. Meanwhile, these LSTIDs are captured by the ionosonde chain which shows that there are perturbations in the virtual heights during the passage of LSTIDs at the height between 200 and 700 km. The occurrence rate of LSTIDs shows a maximum in winter and a minimum in summer. The LSTIDs propagate across China with phase front widths larger than 1500 km. The propagation direction of LSTIDs is northwestward in winter, southwestward in summer, and quasi-westward in equinoxes, respectively. The average period, horizontal phase velocity, and horizontal wavelength of LSTIDs are 79 ± 12 min, 288 ± 43 m/s, and 1503 ± 205 km, respectively. The relative TEC perturbations of the LSTIDs attenuate as the LSTIDs travel across China.