摘要： AbstractThis paper reports the results of space‐based imaging of nighttime medium‐scale traveling ionospheric disturbances (MSTIDs) in 630.0 nm emission by Imager of Sprites and Upper Atmospheric Lightnings (ISUAL), on board FORMOSAT‐2 satellite. The limb integrated measurements, after removing background, reveal multiple bands of intensity perturbation when projected to a horizontal plane corresponding to the altitude of peak emission, with distinct southwest to northeast orientation in the Southern Hemisphere. Simulations are carried out by artificially introducing MSTID fluctuations in model electron density to confirm if the MSTID could be identified in the ISUAL‐viewing geometry. The ISUAL observations in year 2007 are further used to investigate the MSTID features as well as occurrence characteristics in the Southern Hemisphere, most of which are over the ocean where no ground‐based observations are available. The preliminary statistics shows more MSTID occurrence in solstices with peak in June–July months. Majority of the MSTID perturbations have wavelength in the range 150–300 km, and the wavefronts are aligned at about 30°–50° from the east‐west plane. The statistic results of the orientation of wavefronts indicate that Es layer instability might be important in the MSTID generation. 出版者： American Geophysical Union (AGU) 出版日期： 2016-05 出處： Journal of Geophysical Research: Space Physics, 2016-05, Vol.121 (5), p.4769-4781 資源來源： Wiley Online Library - AutoHoldings Journals 版權： 2016. American Geophysical Union. All Rights Reserved. 識別號： ISSN: 2169-9380 識別號： EISSN: 2169-9402 識別號： DOI: 10.1002/2015ja022334
