・Solar radio waves and particle acceleration phenomena
・Planetary radio waves and magnetospheric phenomena
・Jupiter's aurora and volcanic gas emissions of Io
・Thin exosphere of moon and Mercury
・Planetary radiation-belt (Jupiter and the Earth)
・Auroral fine-scale structure
・Development of infrared and visible imaging and spectroscopic instruments
・Development of scientific instruments on satellites
・Development of equipment for radio wave observations
Overview of Research
The Planetary Plasma and Atmospheric Research Center (PPARC) is conducting its research work in collaboration with the Space and Terrestrial Plasma Physics Laboratory and the Planetary Atmosphere Physics Laboratory to elucidate many open questions related to the planetosphere through the observations of "radio waves" and "light" mainly at our six observatories.
Only recently we have come to understand the behavior of planets and moons in the solar system. An enormously valuable contribution to that exploration has been made with the fact that humankind is now able to send space probes to other planets. Nevertheless, to capture a comprehensive picture of planets and to put them into full view, it is necessary for us to observe faint light and radio waves that reach our Earth from far-away planets with the latest technology. The PPARC is the only research center that is currently observing the planets with light and the radio waves from the ground. A better understanding of the planets, which we are trying to accomplish, is leading all of humankind to broaden its frontiers. The targets of our research are expanding to study the dynamics of the solar atmosphere and the Sun-Earth connection, and will extend to an extrasolar planet in the future.
The Planetary Plasma and Atmospheric Research Center has two research sections:
• Planetary Spectroscopy Laboratory
• Planetary Radio-Physics Laboratory
These two research sections are collaborating and are pressing forward their research works to elucidate the environments and phenomena of the planetosphere using radio waves and light by means of observation.
The bases of our observation work are five observatories located throughout an area extending through both Miyagi and Fukushima prefectures. Another base, an observatory based on optical sensing with telescopes, is located at the summit of Mt. Haleakala, Hawaii. Each observatory is located at a suitable place in terms of the environment with respect to radio waves and light. Each is accomplishing observations that are available through the network. The major facilities include the following.
● 60-cm and 40-cm telescopes (T60 and T40) and visible spectrophotometers (Hawaii)
● An optical polarimetric spectrometer (Alaska)
● A VHF-UHF range large radio telescope for researches of the solar plasma and Jupiter's radiation belt (IPRT; Iitate, Fukushima Prefecture)
● An HF-VHF range radio telescope for researches of the solar plasma and Jupiter's magnetosphere (Zao, Miyagi Prefecture)
● An HF range radio wave receiving network facility for researches of Jupiter's magnetosphere and galaxies (Miyagi Prefecture, Fukushima Prefecture)
● A radio wave receiving network facility for LF standard frequency signals for researches of Earth's radiation belt and lightning (Hokkaido, Fukushima, and Fukuoka Prefectures, Taiwan, Thai, Indonesia, Norway, Canada, Alaska)
● Space-borne optical and radio instruments on REIMEI, AKATSUKI, ISS, HISAKI, ERG and JUICE (collaboration with JAXA and ESA)
In collaboration with The University of Hawaii, U.S.A., visible lights coming from planets are observed on the top of Mt. Haleakala. At this moment, a project to develop a 1.8-m diameter offset telescope PLANETS is underway. Furthermore, through collaboration with research organizations in Alaska, Norway, and Sweden, ground-based observation of Aurora is being conducted in the Arctic.
Faculty (Researches) (as of September 30, 2015)
Prof. Takahiro Obara, Director (Study of radiation belt dynamics in Earth's magnetosphere. Study of Sun-Earth connection (Space Weather))
Assoc. Prof. Hiroaki Misawa (Research on planetary and solar non-thermal radio emissions with earth-based observation)
Assoc. Prof. Takeshi Sakanoi (Planetary and terrestrial upper atmosphere with optical remote sensing technique)
Assist. Prof. Fuminori Tsuchiya (High energy particle acceleration and transportation in Jupiter magnetosphere, with development of low-frequency radio wave observation equipment)
Assist. Prof. Masato Kagitani (Study of magnetospheric plasma and exosphere of the planets. Development of instruments on Haleakala Observatory.)
Fig. The new IR-VIS telescope PLANETS will also provide significant tools to be used for planetary science in our solar system. Low scattered-light capability with coronagraph and high-resolution spectroscopy enables to visualize neutral atmosphere and plasmas escaping from icy satellites of Jupiter and Saturn as well as Io that has active volcanoes.
Fig. Jupiter has huge radiation belt whose electron number flux and energy are much larger than those of the earth. PPARC has investigated mysterious dynamics of Jupiter's radiation belt by means of synchrotron radio emission from the high energy electrons using large radio telescopes, IPRT in Iitate, Fukushima, GMRT in India (radio interferometer) etc.