Unmanned magnetometer network observation in the 44th Japanese Antarctic Research Expedition: Initial results and an event study on auroral substorm evolution

In the 44th Japanese Antarctic Research Expedition (JARE-44) during 2003 to 2004, four unmanned magnetometers were deployed in Antarctica to establish a observation network for studying ionospheric and magnetospheric phenomena. Three of them were set about 80 km from Syowa Station, and the fourth was set at Dome Fuji Camp, about 800 km from Syowa. Observations were carried out continuously with a maximum sampling rate of 1 Hz. The purpose of the close network around Syowa was to observe the two-dimensional distribution of the ionospheric equivalent current in a localized area within the field-of-view of the all-sky auroral imager operated at Syowa. Dome Fuji is located at the higher-latitude edge of the auroral zone, while Syowa is located in the middle of it. Auroral observations using the all-sky imager were also carried out at Dome Fuji in 2003. The simultaneous auroral and magnetic observations both at Dome Fuji and Syowa enabled us to study auroral activities in a larger area. This paper describes, the deployment and performance of the unmanned magnetometers in the JARE-44. One auroral substorm event is analyzed in detail to show the usefulness the unmanned magnetometer network.