Traveling wave packets of total electron content disturbances as deduced from global GPS network data

We identified a specific class of mid-latitude medium-scale traveling ionospheric disturbances (MSTIDs), namely traveling wave packets (TWPs) of total electron content (TEC) disturbances. For the first time, we present the TWP morphology for 105 days 1998-2001. A total number of the TEC series, with a duration of each series of about 2.3 h (2h 18m), exceeded 700,000. The data were obtained using the technology GLOBDET of global detection of ionospheric disturbances using a global network of GPS receivers, and the technique of GPS interferometry of TIDs, developed at the ISTP SD RAS. It was found that TWPs are observed no more than in 0.1-0.4% of all TEC series, most commonly during the daytime in winter and autumn. TWPs are quasi-periodic oscillations of TEC with a period of around 10-20 min, and a time duration of the order of 1 h. The TWP amplitudes exceed the amplitudes of "background" TEC fluctuations by one order of magnitude, as a minimum. The radius of spatial correlation of TWPs does not exceed 500-600 km (3-5 wavelengths). We carried out a detailed analysis of the spatial-temporal properties of TWPs by considering an example of the most conspicuous manifestation of TWPs on October 18, 2001 over California, USA. The velocity and direction of TWP displacement correspond to those of mid-latitude MSTIDs. (C) 2003 Elsevier Ltd. All rights reserved.