Generation of ionospheric irregularities upon propagation of solitary internal gravity wave during the major magnetic storm of October 29–31, 2003

Abstract

550.388.2 Using the technique of global detection of ionospheric disturbances, based on processing the data of the global GPS-receiver network, we obtain experimental proof of the existence of a solitary wave (soliton) in the atmosphere during the main phase of the major magnetic storm of October 30, 2003. The soliton with a characteristic duration of about 40 min and a relative amplitude of up to 40%, originated at the moment of the maximum disturbance of the Earth's magnetic field, traveled without changing its shape at a distance of up to 4500 km with a velocity of 1400 m/s, which exceeded the atmospheric sound velocity at the heights of the main electron-density maximum in the ionosphere (about 300 km) by a factor of 1.5. The intensity of variations in the total electron content in the period range 1-10 min increases by an order of magnitude as the soliton propagates from the North-East to the South-West of the USA in the regions with the maximum amplitude of the large-scale disturbance. This corresponds to enhancement of ionospheric irregularities with scales from 10 to 100 km, and also of small-scale irregularities (SSI) with scales of 100 to 1000 m, since the spectrum of the ionospheric irregularities has a power-law shape. Spatiotemporal characteristics of the density distribution of phase slips of GPS signals are close to the corresponding characteristics of the SSI intensity. This agrees with the existing concept that the phase slips result from scattering of GPS radio signals by SSIs. Both the SSI amplitude and the density of phase slips decrease as the soliton decays in amplitude.

Generation of secondary waves due to intensive large-scale AGW traveling

“…One can see that while the LS solitary wave propagated the amplitude of SS TEC variations increased significantly. Similar phenomenon was observed during the main phase of geomagnetic storm on October, 30, from 17 to 23 UT (Afraimovich et al, 2006).…”

Variations in the radio-wave absorption in the ionosphere due to internal gravity waves

“…It has a very simple answer: if the accuracy of such measurements is sufficiently high, then they can also be used for detecting the corresponding perturbations. The measurements of the total electron content and its spatio-temporal variations in the Earth's atmosphere confirm this conclusion [2].…”

“…Such soliton-like waves were detected by the global network of ionospheric stations after strong magnetic storms [2]. Obviously, the spatio-temporal characteristics of such variations differ from those of quasimonochromatic IGW packets.…”

Monitoring global traveling ionospheric disturbances using the worldwide GPS network during the October 2003 storms

“…Moreover, in this case, an increase in the intensity of medium-scale and small-scale irregularities is caused by the dissipation process of intense LSTIDs of auroral origin, accompanied by the appearance of ionospheric irregularities in a wide range of scales, including MSTIDs and small-scale ones. These phenomena were also observed by Afraimovich et al (2006). The propagation directions of those ionospheric disturbances had shifted somewhat clockwise from the south, resulting in a NW-SE phase surface and a southwestward movement in the Northern Hemisphere.…”

“…Several scale irregularities were detected, and an increase in the intensity of medium-scale and small-scale irregularities was caused by the process of dissipation of some intense LSTIDs of auroral origin during the storms (Afraimovich et al, 2006). Ionospheric irregularities (including MSTIDs and small-scale ones) of different scales showed a wide range of horizontal phase velocity (Vph).…”