Acquisition of the Scandinavian IMS Magnetometer Array Data and Studies of Geomagnetic Rapid Variations

在国际磁层研究(IMS)期间(1977-1979)，利用北美磁力计网络(NAMN)和斯堪的纳维亚磁力计阵列(SMA)这两个磁力计网络进行了高时间分辨率的地磁观测。虽然NAMN的数据通过STP的世界数据中心(WDC)-A向公众开放，但SMA的数据只在明斯特大学的一个研究小组内使用，该研究小组负责SMA的运作。京都大学的地磁学WDC-C2就向公众公布数据进行了谈判，并于1989年将一套备份胶片移交给了该中心。本研究项目的目的是安排数据的发布，并利用这些数据对地磁快速变化进行分析。原始备份数据记录在35 mm的电影胶片上，分别卷在42个直径40 cm的大卷轴上。一次连续记录的胶片长度约为50米，对于通常的胶片阅读机-印刷机来说，这不能容纳在正常的较小卷轴(直径9.2厘米，100英尺卷)中。此外，最好不要将原始胶片用于日常分析或数据服务，因为这是世界上唯一的一组备份数据。然后我们决定将原始的备份胶片复制到特殊的薄膜中，这样一个正常的卷轴就可以容纳50M的数据。在这个项目的第一年，整个大卷轴上的数据被复制到567个小胶卷中。第二年，在每个卷轴上标出了站点和数据周期的名称，并编制了数据分析参考清单。然后结合NAMN的资料对2次地磁突然启动事件和2次地磁脉动事件的资料进行了分析。结果表明，该资料可有效地用于研究地磁快速变化的局部精细结构和纵向变化。

During the IMS (International Magnetospheric Study) period (1977-1979) high time resolution geomagnetic observations were conducted by two magnetometer networks, North American Magnetometer Network (NAMN) and Scandinavian Magnetometer Array (SMA). While the data from NAMN have been open to the public through the World Data Center (WDC)-A for STP, the data of SMA had been used only within a research group of University of Munster, which took responsibility for the operation of SMA. The WDC-C2 for Geomagnetism, Kyoto University, negotiated about release of the data to the public and a set of th back-up film was transferred to the Center in 1989. The purpose of this research project was to make arrangements for the data release and to make analyses of geomagnetic rapid variations by using the data.The original back-up data were recorded on 35mm cinema film separately rolled in 42 large reels of 40cm diameter. Film length of one continuous recording is approximately 50 meters, which can not be accommodated in a normal smaller reel (9.2cm diameter, 100 feet roll) for usual film reader-printers. Further, it is desirable not to use the original film for daily analyses or data services because this is the only one set of back-up data in the world. Then we decided to copy the original back-up film into special thin film so that 50m of the data can be accommodated in a normal reel.In the first year of this project the whole data on the large reels were copied into 567 small reels of film. In the second year the names of the stations and data periods were labeled on each reel and reference lists for data analysis were prepared. Then the data were analyzed for 2 geomagnetic sudden commencement events and 2 geomagnetic pulsation events by combining the data from NAMN. It was shown that the data can be used effectively for studies of both local fine structure and longitudinal variation of geomagnetic rapid variations.