T Tsugawa1*, M Nishioka1, H. Kato1 and M. Ishii1
*1National Institute of Information and Communications Technology, 4-2-1 Nukui-Kitamachi, Koganei, Tokyo 184-8795, Japan


When the solar activity is high and the magnetic field in the solar wind is suitable to the Earth’s magnetic field, the solar wind pass through the magnetic field and effect to near-Earth space, satellite, space station, or radio infrastructures. We monitor the condition of sun, solar wind and near-Earth space. This is the space weather. For example of space weather application, ICAO, International Civil Aviation organization, UN is now planning to use space weather information in civil aviation to keep stable use of the communications and satellite positioning and avoid hard radiation exposure.

Japan has contributed to space weather researches for nearly a century. Work on space weather research began in 1915 at the Hiraiso branch (known as the Hiraiso Solar Observatory, National Institute of Information and Communications Technology (NICT) and closed in 2016). Ionospheric research for stable radio telecommunications started before World War II, and radio wave propagation forecasting service began in the 1940s. Routine ionospheric observation by ionosondes has been conducted in Japan and Antarctica since 1957, which is the International Geophysical Year (IGY). NICT has been operating a space weather forecasting service as one of the International Space Environment Service (ISES) Space Weather Information Centers since 1989. NICT had hosted and operated the WDC for Ionosphere since 1957 and have been operating the WDC for Ionosphere and Space Weather (WDC-ISW) under the auspices of ICSU WDC since 2012. NICT collects and archives data and information on ionosphere and space weather, and makes them available to the public. Published data are used by a wide range of users including public organizations, research institutions, and universities.

Recently, we have been replacing the current 10C type ionosondes with Vertical Incidence Pulsed Ionospheric Radar 2 (VIPIR2) ionosondes which can separate the O-mode and X-mode ionospheric echoes automatically. In addition to ionosonde observations, we have developed two-dimensional total electron content (TEC) observation technique over Japan using the dense GNSS network, GEONET since mid-1990s. The TEC maps are now available on a real-time basis using streaming data of GEONET. We have developed ionospheric storm monitoring system based on the real-time observation data and a new ionospheric storm scale, I-scale, which is defined using the long-term ionospheric data in Japan (Nishioka et al., 2017). In this presentation, we will introduce recent activity and future plan of ionospheric observation in NICT.


Michi Nishioka, Takuya Tsugawa, Hidekatsu Jin, and Mamoru Ishii (2017), Universal ionospheric storm scale based on TEC and foF2 statistics, Space Weather, 15, 228-239, doi:10.1002/2016SW001536.