Report on the MT-135JA meteorological rocket experiment (JARE-26)

Abstract

The present report outlines meteorological rocket MT-135JA experiments performed first at Syowa Station (69°S, 40°E), Antarctica in the operational aspects. This experiment was conducted by the 26th Japanese Antarctic Research Expedition (JARE-26; the main year of observation is 1985) as one of the projects of the international cooperation program, Middle Atmosphere Program (MAP; 1982-1985). The target of the experiment was internal gravity waves in the Antarctic middle atmosphere. The MT-135JA rocket measures winds and temperature in the altitude range from about 20 to 60km with the altitude resolution of about 1km. The MT-135JA rocket had been developed for the Antarctic cold condition. The JARE-26 launched 11 rockets. The meteorological rocket experiment was a first experience for the JARE. Moreover, the successive launches of rocket at intervals of about two hours, which had been planned for sufficiently detecting internal gravity waves, were also first performed at Syowa Station, although the experiments of the other rockets (S-160JA, S-210JA, S-310JA) mainly for sounding the aurora phenomena had long been performed at Syowa Station since 1970 (JARE-11). Two rockets were launched on 30 January and on March in 1985 for testing the performance of the ground facilities and the rocket itself. Five rockets were successively launched on 28 June for detecting internal gravity waves in winter when the waves are expected to be most active. On 25 September, four rockets were also successively launched for investigating the waves in the transient period from the winter to summer circulation of the middle atmosphere. Observational data were obtained in an almost sufficient manner. Simultaneous observations of the sodium density arounds the mesopause level (∿80km) by the laser radar and the winds around the mesopause level by the VHF meteor radar were performed at Syowa Station. The regular experiments of meteorological rocket at Molodezhnaya Station (68°S, 46°E) at a distance of about 300km from Syowa Station were made on the same dates. The anticipated results were almost obtained. This report describes the development of the MT-135JA rocket and the other preparations in Japan, transportation of the rockets from Japan to Syowa Station, construction of an MT-135JA rocket launcher as one of the projects in the summer operation of the JARE-26,progress in the rocket experiment, operations at the time of the rocket launches, outlines of the result of the flight experiment in the operational aspects and so on. Scientific results of the experiment will be published in other scientific journals.