Links between the space and the earth observed by remote-sensing techniques
The target of the Space and Upper Atmosphere Researches Group ranges from the stratosphere (above 10 km) to the interplanetary space of the solar system.
Study on aurora and a link between solar wind, magnetosphere, and ionosphere
Aurora, the most majestic and beautiful phenomenon in the polar region, is still puzzling and of great interest to the researchers. Aurora is excited by electrons and protons precipitating from the space near the Earth (Geospace) to the polar atmosphere along the geomagnetic field lines and reflects variations in the Geospace environment, which changes dynamically due to an interaction between the solar wind, the magnetosphere and the ionosphere.
We have been conducting ground-based camera, radar, and magnetometer network observations at Syowa Station in Antarctica, and at stations in Iceland near the geomagnetic conjugate point. The network also includes observations at other Antarctic bases, and in the Northern Europe. Such observational data are used to study the recent scientific topics such as the generation mechanism of auroral breakup, and the processes of energy and momentum transfer between the solar wind, magnetosphere and ionosphere.
Middle and upper atmosphere observations
The transient region between the middle (10-100km) and the upper (100km -) atmospheres is a boundary region between the space and the Earth. The upper atmosphere is partially ionized acting as plasma particles, whereas it is more like fluid and neutral in the middle atmosphere. In contrast to the aurora in the upper atmosphere, outstanding phenomena in the polar middle atmosphere are an ozone hole, polar stratospheric clouds (PSC) and polar mesospheric clouds (PMC). In order to precisely measure the polar middle and upper atmospheres, varying with response to meteorological disturbance from below, solar activities from above, and global meridional circulations of the atmosphere, we are carrying out various ground-based measurements in the Arctic and the Antarctic regions.