PROGRAM: P-29
Title:
RECENT ACTIVITIES OF WDC FOR IONOSPHERE AND SPACE WEATHER (WDC-ISW)Abstract:
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.
References:
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.