VHF radar observation of the middle atmosphere at Syowa Station, Antarctica

The newly developed pulsed Doppler radars with 50 and 112 MHz were installed at Syowa Station (69 deg 00'S, 39 deg 35'E geographic; 70.0 deg S, 80.2 deg E geomagnetic) in 1982 and 1983, respectively. They have the nominal peak power of 15 kW; the narrow antenna beams (4 deg in the horizontal plane) in two different directions (approximately geomagnetic south and geographic south with a crossing angle of about 33 deg), the three operation modes (spectrum, double-pulse and meteor mode). The radars were designed to measure the intensity and Doppler velocity of auroral radar echoes due to the 3- and 1.34-m irregularities appearing often in the disturbed E region and also to detect the meteor echoes in the 80 to 100 km altitudes, thereby to clarify how the middle atmosphere in the polar region behaves in response to the energy input from the magnetosphere, especially during a substorm. Some initial results obtained through the radar operation during 1982 to 1983 are presented to show that this system is useful for continuous monitoring of the lower auroral ionosphere.