Statistical Study of Medium-Scale Traveling Ionospheric Disturbances Observed with a GPS Receiver Network in Japan
Using densely spaced GPS receivers in Japan, we investigated two-dimensional maps of total electron content (TEC) perturbations with a spatial resolution of 0.15×0.15° in longitude and latitude to reveal the statistical characteristics of medium-scale traveling ionospheric disturbances (MSTIDs). We found that MSTIDs can be categorized into three groups: daytime, nighttime, and dawn and dusk MSTIDs. Daytime MSTIDs frequently occur in winter and tend to propagate southeastward. We speculate that daytime MSTIDs are caused by atmospheric gravity waves in the thermosphere. Nighttime MSTIDs frequently occur in summer and propagate southwestward. This propagation direction supports the notion that polarization electric fields could play an important role in generating nighttime MSTIDs. Dawn and dusk MSTIDs frequently occur in summer and propagate eastward and north-northwestward, respectively.
KeywordsGlobal Position System Gravity Wave Total Electron Content Global Position System Receiver Neutral Wind
GEONET GPS data were provided by the Geographical Survey Institute of Japan.
- Bristow WA, Greenwald RA, Villain JP (1996) On the seasonal dependence of medium-scale atmospheric gravity waves in the upper atmosphere at high latitudes. J Geophys Res 101:685–699Google Scholar
- Hines CO (1960) Internal atmospheric gravity waves at ionospheric heights. Can J Phys 38:1441–1481Google Scholar
- Hocke, K, Schlegel K (1996) A review of atmospheric gravity waves and traveling ionospheric disturbances: 1982–1995. Ann Geophys 14:5917–5940Google Scholar
- Kotake N, Otsuka Y, Tsugawa T, Ogawa T, Saito A (2007) Statistical study of medium-scale traveling ionospheric disturbances observed with the GPS networks in Southern California. Earth Planets Space 59:95–102Google Scholar
- Miller CA, Swartz WE, Kelley MC, Mendillo M, Nottingham D, Scali J, Reinisch B (1997) Electrodynamics of midlatitude spread F, 1 Observations of unstable, gravity wave-induced ionospheric electric fields at tropical latitudes. J Geophys Res 102:11,521–11,532Google Scholar
- Ogawa T, Nishitani N, Otsuka Y, Shiokawa K, Tsugawa T (2009) Medium-scale traveling ionospheric disturbances observed with the SuperDARN Hokkaido radar, all-sky imager and GPS network, and their relation to concurrent sporadic-E irregularities. J Geophys Res 114:A03316. doi:10.1029/2008JA013893CrossRefGoogle Scholar
- Otsuka Y, Shiokawa K, Ogawa T, Yokoyama T, Yamamoto M (2009) Spatial relationship of nighttime medium-scale traveling ionospheric disturbances and F region field-aligned irregularities observed with two spaced all-sky airglow imagers and the middle and upper atmosphere radar. J Geophys Res 114:A05302. doi:10.1029/2008JA013902CrossRefGoogle Scholar
- Shiokawa K, Otsuka Y, Tsugawa T, Ogawa T, Saito A, Ohshima K, Kubota M, Maruyama T, Nakamura T, Yamamoto M, Wilkinson P (2005) Geomagnetic conjugate observation of nighttime medium-scale and largescale traveling ionospheric disturbances: FRONT3 campaign. J Geophys Res 110:A05303. doi:10.1029/2004JA010845CrossRefGoogle Scholar