Stormed Ionospheric Weather Observed by Using FORMOSAT-3/COSMIC

This paper demonstrates that the Radio Occultation (RO) is a powerful tool to scan the vertical electron density structure during the 02 May 2010 moderate magnetic storm period. We examine fluctuation features in the RO total electron content (TEC) profiles from 150 km to 600 km altitude probed by GPS Occultation eXperiment (GOX) on board the Formosa Satellite 3/Constellation Observation System for Meteorology Ionosphere and Climate (F3/C) during the ionospheric storm. To find storm fluctuated signatures in the vertical direction, ROTEC profiles before and after the storm onset are subdivided into four time sectors of midnight, dawn, noon, and dusk, and three regions of low-, mid-, and high-latitudes. A wavelet transform is applied to study the ROTEC profiles 2 days before and after the storm onset. Two types of spectra, one wedge-shape with the wavenumber less than about 0.1 km-1 (wavelength 10 km) at the altitude below about 250 km, and the other tower-shape with the peak-wavenumbers of 0.05 to 0.06 km-1 (wavelength 16 to 20 km) at peak-heights of 300 to 400 km altitude, are observed before and after the storm onset. However, the tower-shape spectra become much more intense and expend to a higher altitude, especially at all latitudes in the midnight sector and the high-latitudes in all sectors. Meanwhile, concurrent vertical TEC measurements derived by worldwide ground-based GPS receivers show that the intrinsic frequency of the fluctuations is about 20 to 30 minutes, which becomes much more intense in the high latitude after storm onset.