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Characteristics of the saucer emissions are studied by using ISIS VLF data which were received at Syowa Station by the wintering party of the 17th Japanese Antarctic Research Expedition in 1976-1977. Saucers were observed most frequently in the nighttime in winter and were scarcely observed in summer, The magnetic latitude ranges in which saucers were observed are ～60゜-75° in the nighttime and ～70°-80゜ in the daytime. These occurrence regions are located at the higher latitude side of the plasmapause and at the lower latitude side of the hiss occurrence regions. The shapes of saucers on frequency-time spectra showed generally two different types,i e, symmetrical hyperbolic shapes and symmetrical V-shapes

Because of the importance of the balloon observations in the polar region, a project, Polar Patrol Balloon, is proposed in which a balloon will be able to float and observe around Antarctica for a month. In this project, the balloons are to be launched from some bases in Antarctica where there is no sunrise in the winter and no sunset in the summer, and a zero pressure balloon can maintain its altitude for one month by dropping a small amount of ballast. A study of meteorological feasibility had been made for this project, and it was found that a period for the balloon to fly around the pole is about one week in the winter and a few weeks in the summer at an altitude of 30km. The deviation of the trajectory from a circle is smaller in the summer season. A feasibility study was also made for power supply, on board memory storing observed data, and auto-ballasting system to perform the flight of about one month. The balloon will be located by ARGOS systems during the flights. Some merits of possible international collaboration for this project are also discussed

It is scheduled that two sounding rockets are launched from Syowa Station, Antarctica in the austral winter of 1985 as part of the international Middle Atmosphere Program (MAP), by the wintering party of the 26th Japanese Antarctic Research Expedition. This experiment aims at the study of the wave-particle interaction processes on auroral field lines. The present paper gives an outline of the mission plan of the experiment

The summer operations of the 22nd Japanese Antarctic Research Expedition Party are summarized. The icebreaker FUJI, carrying 450t of cargo and 44 members of the expedition party led by Prof. Y. YOSHIDA, left Tokyo on November 25,1980. The icebreaker arrived at the edge of pack ice, about 200 miles from Syowa Station on December 31,1980. Then, the icebreaker reached the point suitable for air transport, about 27 miles from Syowa Station on January 1,1981. All activities at Syowa Station went on smoothly as previously arranged. The air transport started on January 3,and almost all cargos except fuel were transported to Syowa Station by January 15. The air transport of fuel was accomplished by January 28. The construction works of an information processing building, a MARISAT station, unmanned observatory at West Ongul Island, radio wave receiving antenna and so on were completed by February 3. As field activities, SCUBA diving for biological survey was carried out fifteen times in frozen sea near Syowa Station. Geodetic and geological surveys were carried out at Tenmondai Rock, Akebono Rock, and Sinnan Rocks located on the coastline of Prince Olav Coast. Two field parties for explosion seismic experiment and POLEX-South meteorological experiment made oversnow traverses to Mizuho Station. The icebreaker FUJI left Syowa Station on February 6 in the summer operation. She visited Molodezhnaya Station from February 10 to 13 for the cooperative research program of upper atmosphere physics. After FUJI left the frozen sea on February 19,oceanographic and biological observations were carried out at 13 stations. The FUJI returned to Tokyo via Port Louis and Singapore on April 20,1981.

The semi-polar orbital and the polar aeronomy observation satellite "EXOS-D", will be launched in February 1989 by the Institute of Space and Astronautical Science. The National Institute of Polar Research is planning to carry out coordinated ground and satellite observations by real-time EXOS-D data aquisition. In this paper, the size of a 10-meter dish which is determined by the results of the network analysis on the EXOS-D orbit data of 10000km apogee, and various technical conditions when it is constructed at Syowa Station are described. By the construction of this new 10-meter dish antenna at Syowa Station, it will become possible for us to track and observe not only the EXOS-D but also LANDSAT, MOS and other remote sensing satellites. And if it is used as one point in a VLBI system, a precise measurement of the global continental drift will be made.

Satellite data acquisition facilities for ISIS-1 and 2 were built up at Syowa Station in January 1976, and the VLF wideband and topside sounder data have been received on the routine basis since April 1976. The occurrence regions of VLF hiss and saucer emissions in the southern polar region were studied statistically by using the ISIS-1 VLF data of the 110 orbits and the ISIS-2 VLF data of the 155 orbits which were received by the 17th and 18th Japanese Antarctic Research Expedition wintering parties in 1976 and 1977. It is found that the hiss emission region with the occurrence probability larger than 50% is located at 75°–85° geomagnetic latitude in 10–14 MLT in the dayside and at 65°–80° geomagnetic latitude in 20–02 MLT in the night side, while the saucer emission region with the occurrence probability larger than 30% is located at 75°–85° in 10–18 MLT in the dayside and at 60°–70° in 18-02 MLT in the night side. It is suggested that the hiss and saucer emission regions in the dayside are closely related to field-aligned currents in the cusp region. It is also found that the altitude of the saucer emission region shows a clear seasonal variation, i e., saucer emissions are observed in the altitude range of 500–4000 km with a maximum occurrence at 2500–3000 km in the austral winter season (April-September), while they are observed at the altitude higher than 3000 km in the summer season.

Simultaneous observations of ELF・VLF emissions, magnetic variations, cosmic noise absorption and auroras have been carried out at Syowa and Mizuho Stations since June 1976. Mizuho Station is located at a distance of ～270 km poleward on the same magnetic meridian as that of Syowa. From the ELF emission data observed at both the stations, the following results were obtamed 1) Frequency-time spectra of ELF chorus emissions were quite similar at both the stations. However, it ls found that the intensity in the lower frequency range (

ISIS VLF data were received at Syowa Station, Antarctica in 1976. These data were compared with VLF and auroral data simultaneously observed on the around. In general, hiss and saucer emissions were succesively observed on ISIS 2, when ISIS 2 moved from the polar cap towards the low latitude. It is found that the geomagnetic field lines through a northernmost auroral arc are located between the occurrence regions of hiss and saucer emissions. It is also found that spectra of hiss emissions observed on the ground (Syowa) are not similar to those of VLF emissions observed in the region connected with field line at the satel-lite altitude, but are similar to those of VLF emissions observed near the same geomagnetlc latitude as that of Syowa Station. The result suggests that auroral hiss emissions do not propagate along the geomagnetic field lines from the statellite height (～1400 km) to the ground. The calculation by means of the ray theory suggests that hiss emissions propagate along a non-ducted path from the satellite height to the ground

The Inter-Union Special Committee on Solar-Terrestrial Physics (SCOSTEP) has proposed to carry out the Middle Atmosphere Program (MAP) in 1982-1985 as an international scientific project. Coordinated observations of the middle atmosphere in the area around Syowa Station in Antarctica by means of ground-based station network, aircraft, balloons, rockets and satellites are now under consideration in order to study structures and seasonal and diurnal variations of the polar middle atmosphere in the altitude range of 10-120 km. The report gives an outline of this project.

The wintering party of the 26th Japanese Antarctic Research Expedition composed of 35 personnel carried out routine observations and research activities at Syowa and Mizuho Stations, along the coast of Lutzow-Holm Bay and in the dome area of East Queen Maud Land from January 1985 to January 1986. The main research activity at Syowa Station was a coordinated observation of the polar middle atmosphere, which was performed as part of the International Middle Atmosphere Program (MAP). The middle atmosphere in the altitude range of 10-120km was observed by a combination of remote sensing techniques from the ground and spacecraft and in situ measurements by 9 balloons and 13 rockets. The remote-sensing facilities operated on the ground were ruby and dye laser radars, VHF doppler radar, multi-beam riometer and auroral TV cameras. In addition to the MAP activities at Syowa Station, survey trips for environmental research were carried out at short intervals along the coast of Lutzow-Holm Bay. Glaciological and meteorological studies were carried out, as part of the International Antarctic Glaciological Project (IAGP), at Mizuho Station (70.7°S, 44.3°E), Advanced Camp (74.2°S and 35.0°E), Dome Camp (77.0°S and 35.0°E), and on the traverse routes. The 200-m ice-core drilling was completed at Advanced Camp. The top of the East Queen Maud Land dome was discovered to be located at 77°22′24″S and 39°36′50″E with the altitude of 3807m above sea level.

This campaign has been organized by the National Institute of Polar Research as a cooperative project with the Science Institute, University of Iceland. This campaign aims at a further understanding of physical processes in auroras by a coordinated observation of magnetic field variations, magnetic ULF waves, ELF-VLF emissions, cosmic noise absorption, and spatial and temporal variations of auroras in the magnetically conjugate polar region. The campaign takes advantage of geographical condition that the conjugate points of Syowa, Mizuho and Molodezhnaya Stations in Antarctica are located in the vicinity of Husafell, Isafjordur and Husavik in Iceland. With the data recorded at the three conjugate station pairs Syowa-Husafell, Mizuho-Isafjordur, and Molodezhnaya-Husavik, we investigate the temporal and spatial conjugacy of both auroras and wave phenomena associated with auroral particle precipitation. Then we study the auroral particle acceleration process in the ionosphere-magnetosphere energy coupling system and also the generation and propagation mechanisms of ULF, ELF and VLF plasma waves. Three Japanese scientists have been in Iceland from August 12 to October 2. In the first half of the period of their stay they visited Isafjordur (66.1°N, 23.1°W) and Husavik (66.0°N, 17.4°W) to find locations suitable for observations of geomagnetic field variations, cosmic noise absorption and ULF, ELF and VLF natural waves. During their stay at Husafell, various kinds of sensors (fluxgate magnetometer, search coil magnetometer, ELF-VLF wave receiver, riometer and all-sky camera) and recording facilities were set up. These facilities are operated by the Icelandic research fellow until next summer.

A plastic balloon of 5000 m^3 was launched at Syowa Station (L=61), Antarctica, at 1138 UT on December 12, 1976, and the horizontal electric field and auroral X-rays (>25 keV) were simultaneously measured for about 10 hours m the stratosphere. During the balloon flight a weak geomagnetic substorm occurred corresponding to the eastward electrojet in the afternoon side of the auroral zone, and the electric field increased from 10 mV/m to 40 mV/m. There were good correspondences between the southward electric field and geomagnetic horizontal component and between the westward electric field and declination. Observed auroral X-rays were homogeneous throughout the all sky and of diffuse type. The X-rays were enhanced three times during the substorm. The electric field clearly decreased on the second X-rays event but there was no clear change on the other two events. There was no special change in the electric field direction during the geomagnetic substorm. One hour averages of the observed electric field show a clear S_q^p pattern. The height-integrated conductivities were calculated from the observed electric field and the geomagnetic variations at Syowa Station, getting the values of 1-10 mho. The Hall conductivity increased during the substorm.

Conjugate observations of ELF-VLF emissions, magnetic pulsations and auroras were carried out at Syowa Station in Antarctica and Husafell in Iceland from July 29, 1977 to September 18,1977. Husafell is located at a distance of about 50 km from the conjugate point of Syowa Station. Conjugacies of ELF-VLF emissions depend on emission types, such as polar chorus, quasiperiodic emissions, burst of discrete emissions and auroral hiss. Polar chorus and quasi-periodic emissions are observed simultaneously at the conjugate-pair stations. This suggests that the emissions are generated near the equatorial region in the outer magnetosphere and propagate to the both hemispheres along the field lines of force. Conjugacy of bursts of discrete emissions and auroral hiss is generally low. The emission intensity of auroral hiss is much stronger at Syowa Station (winter hemisphere) than at Husafell (summer hemisphere). Just the opposite tendency is observed for bursts of discrete emissions. The low conjugacy of these emissions may depend on the differences in geophysical conditions, such as the magnetic field, magnetic dip angle and the plasma density and also it depends on properties of the generation region of the emissions.

Measurements of geomagnetic field intensity were carried out in the vicinity of Syowa Station (East and West Ongul Islands, Teoya, Langhovde, and Skarvsnes) and on the route between Syowa and Mizuho Stations by the 17th wintering party of Japanese Antarctic Research Expedition. The total magnetic intensity was measured on the ground by using a portable proton magnetometer, and then iso-intensity contours were drawn. From a comparison of these magnetic maps with the geological maps, it is found that there is a close correspondence between the distribution of magnetic anomaly and the geological structure.

Coordinated observations of the polar middle atmosphere are being carried out at Syowa Station in Antarctica as part of the Middle Atmosphere Program (MAP) for 1982-1985. The middle atmosphere is measured by a combination of remote sensing techniques from the ground, aircraft and spacecraft and in situ measurements by aircraft, balloon and sounding rocket. The main ground-based remote sensing facilities are laser radar, VHF doppler radar, infrared spectrometer and Dobson spectrophotometer. This paper gives an outline of this project.

As described in Part I, from a feasibility study of the Polar Patrol Balloon (PPB) which circles along a selected geographic latitude over Antarctica, it has been concluded that the PPB will be developed in the near future. The application of the PPB system is discussed in this paper. By the PPB experiment many subjects of upper atmosphere physics, meteorology, glaciology, cosmic ray physics and logistics will be solved, the subjects which have not been solved by technique of spacecraft and sounding rocket.

Conversational spectral analysis program (CSAP) system is apphed to the simultaneous magnetlc pulsation data of November 17, 1976 when various kinds of ULF penomena were observed at Syowa and Mizuho Stations. In this paper, the analysis procedure, the outline of the CSAP system with graphic display terminal and analysis results are shown and discussed. The results show that the CSAP system is useful for studying magnetic pulsation data.

Since 1984 the National Institute of Polar Research, the Institute of Space and Astronautical Science and collaborative scientists have conducted the long-term circumpolar balloon program that is called Polar Patrol Balloon (PPB) project, and they also have developed ballooning technologies for this program. This project aims at establishing a station network in the stratosphere over the Antarctic region for geophysical and astrophysical observations. Two test flight experiments that were performed by the 28th Japanese Antarctic Research Expedition (JARE) in 1987 have convinced us that PPB would come back to the launching area with a good possibility. During 1991 and 1993 (JARE-32-34) at Syowa Station. The PPB experiments will consequently be done for scientific researches. This brief paper reports unique advantages of PPB, specifications and expected trajectories of PPB, and planned scientific researches with PPB.

The S-210JA-20 and 21 rockets were launched into auroras at 2340 UT on June 24, 1976 and at 0023 UT on July 26, 1976, respectively. Both rockets were launched when the ISIS satellite was passing overhead near Syowa Station. In this report the scientific subject of these experiments is described first and the relation-ship among VLF waves recorded simultaneously at the three different altitudes (the ground, ～60-120 km, and ～1000-3000 km) is briefly discussed. The relation of VLF waves and electrostatic plasma waves in the 0.1-10 MHz range measured on the rockets to precipitating electrons is also summarized.

The operation of Syowa Station has been maintained by the help of radio communications since 1957. The traffic capacity in Antarctica has increased rapidly due to the expansion of the station, increased members, substantial research items and establishment of advance stations. In the first decade, the A1 and A4 for PIX and FAX modulation system occupied the main stream of radio communication system between Syowa Station and Japan and the intra-Antarctic communications. But the increased traffic caused the shortage of circuit margin. The long distance bus link has to change the high speed PCM system through the geostationary satellites from HF link as if via Marisat. Much improvements are required in the following points : the intra-Antarctic system, the radiowave propagation between 300 and 500km, technical research on the local communication, and the data collection system of orbital satellites. The present situation and the future improvement of Antarctic communication are described in this paper.

Observations and communications in the Antarctic region will be greatly developed by using satellites. The satellite technology is applied to : 1) communications between the stations in the Antarctic region and their mother countries, 2) domestic communications in the Antarctic region, 3) remote sensings of the Antarctic region, 4) observations of the ionosphere and the magnetosphere in the polar reeion.In this paper, possibilities of these applications are discussed, and an Antarctic satellite project is proposed.

Multiwavelength laser radar system was installed at Syowa Station in 1983 by the 24th Japanese Antarctic Research Expedition for measurement of the middle atmospheric phenomena in cooperation with International Middle Atmosphere Program (MAP). The laser radar can simultaneously shoot two kinds of laser pulses (0.6943μm : the fundamental wave, 0.3471μm : the second harmonic wave) by means of ruby laser with regulated repetition frequencies (maximum : 1Hz) and receive scattered light by a telescope with the 50 cmφ-lens in efficient diameter. The measurement can be done by using a photon counter for each wave and A-scope for the fundamental wave. The test observation had been successfully made in Japan and it showed the remarkable increases of the strato-spheric aerosol due to the volcanic eruption of Mt. El Chichon. It was also inferred that the size distribution of the particles in the aerozol layer is inhomogeneous.

In order to investigate problems of coupling between the middle atmosphere and the ionosphere, and also between the ionosphere and the magnetosphere, it is very important to carry out comprehensive observations of waves, partides, electric field and magnetic field in a high latitude region by a ground-based station, a balloon, a rocket and a satellite. For that purpose, the observation by the international cooperation between Japan and Sweden is planned in the Arctic region. Esrange (67°53'N, 21°O4E) in Sweden is chosen as the observation place, because it is ideally situated for observing various phenomena caused by charged particles coming from space to enter the atmosphere. In this paper, the comprehensive observation plan is described.

From the magnetic pulsation data recorded at the Syowa Station-Iceland conjugate pair, it is found that there are at least two pulsation bands in the Pc 3-5 frequency range in the daytime. 0ne pulsation band occurs in the 20-40 mHz range, while the other band occurs in the 4-8 mHz range, often independently of the 20-40 mHz band. The f-t spectral patterns of these pulsations are quite similar at the coniugate points, with the wave phase characteristics of odd-mode standing oscillations of local magnetic field lines. It is also found that the orientation angles of the polarization ellipses in the H-D plane switch across the magnetic local noon. These results suggest that the 20-40 mHz band and the 4-8 mHz band are standing oscillations of resonant field lines excited by external driving forces such as the Kelvin-Helmholtz instability on the magnetopause and/or the MHD waves generated near the bow shock

Telemetry signals from the first Japanese polarorbitting satellite, EXOS-A (Kyokko) are being received at three satellite acqusition stations, i.e., Kagoshima, Churchill and Syowa Satellite Earth Stations. In this report, the progress of the data acqusition at Syowa is described.

This report describes a result of the Japanese balloon campaign carried out in March 1982,at Stamsund (68°09′N, 13°46′E) in northern Norway. The objective of this campaign was to study auroral particle precipitation and related ionospheric phenomena. Two balloons were successfully launched on March 19 and 20,1982. The first one was launched in the recovery phase of an auroral substorm, and X-ray pulsation and microburst, correlated well with VLF emissions, were observed. The second one was launched at the substorm time, and the change of the ionospheric electric field direction was observed in association with auroral activities. The process of planning, the preparation and the operation for this campaign are also described for the convenience of future balloon campaign.

A plan is described for lidar observations of the middle atmosphere which will be made by the 26th Japanese Antarctic Research Expedition, 1984-1986 (JARE-26) at Syowa Station (69°00′S, 39°35′E). This work has been planned as part of the Middle Atmosphere Program (MAP). The objectives of observation are to obtain the temporal and spatial variations of the sodium atomic layer in the upper mesosphere and those of temperature profile in the range from the upper stratosphere to the mesosphere by a tunable dye laser in addition to the aerosol observation in the lower stratosphere by a ruby laser which has been already started by the JARE-24 since 1983.

Conjugate observations of ELF-VLF emissions, geomagnetic pulsations and auroras were carried out at Syowa Station in Antarctica and at Husafell in Iceland from July 29, 1977 to September 18, 1977 Husafell is located at a distance of about 60 km from the conjugate point of Syowa From a prelimmary analysis of the ELF and VLF emission data, the following results were obtained 1) Conjugacy of auroral chorus emissions observed in the early morning is low. The emission intensity is larger at Husafell than at Syowa. 2) Daytime ELF chorus emissions show a good conjugacy. However, it is found that the intensity in the low frequency range is greater at Syowa than at Husafell, and vice versa in the high frequency range. 3) QP emissions are observed simultaneously at the conjugate-pair stations. 4) Conjugacy of auroral hiss emissions is generally low during this observation period. The intensity is much higher at Syowa (winter hemisphere) than at Husafell (summer hemisphere)

DC and AC (8-110 Hz) electric fields were observed in the auroral ionosphere up to 120 km with spherical double probes on board the sounding rockets S-210JA-24 and 25 at Syowa Station. The rockets passed close to auroras. The DC electric fields observed during substorms at magnetic midnight are composed of the height-independent electric field of about 20 mV/m and the local electric field of up to 30 mV/m. The former electric field is the large scale electric field generally existing in the auroral ionosphere, and the latter local electric field will be the effect of space charges produced by precipitating auroral particles, peaking at the heights between 100-115 km. Strong AC noises were observed in the limited altitude range of 96-112 km during both the ascent and the descent. The noise frequencies varied with altitude and were ranged between 20 and higher than 110 Hz. The noises appeared in the direction perpendicular to the DC electric field. These characteristics suggest that the noises might be generated by plasma instability in the ionospheric current layer.

Continuous observations of geomagnetic pulsations were carried out from July 20 to 29, 1970 at Mizuho Camp which had been established by the llth wintering party of the Japanese Antarctic Research Expedition as a scientific observatory in the Antarctic inland area. The geomagnetic pulsations were measured with an induction magnetometer and were recorded simultaneously using both a PWM data recorder and a pen-oscillograph. Similar observations were made at Syowa Station which is about 300 km northwest of Mizuho Camp. By comparing the data from these two stations, it is noticed that PC 2, 3 and Pi 1 pulsations usually occur concurrently at both the stations, whereas Pi bursts often occur at only one station, suggesting that the occurrences of Pi bursts are restricted within small area.

VLF emissions were observed at Syowa Station by the 11th wintering party of the Japanese Antarctic Research Expedition in 1970-1971. The present paper deals particularly with the records of auroral hiss emissions, which are believed to be emitted by precipitating electrons in the aurora. It is shown that the power spectrum of the hiss emissions is confined in the low-frequency range between 4-32kHz if the auroral arcs lie near the poleward horizon of Syowa Station, while it is extended to frequencies as high as 128kHz if the active auroral arcs appear near the zenith. This can be explained by differences in the height of the emission region and in the propagation path of the hiss in the ionosphere : the high-frequency (～64kHz) hiss is emitted at low altitudes of 1000-1500km, its propagation path being limited to a narrow region near the location of the auroral arcs, while the low-frequency (～8kHz) hiss is emitted at higher altitudes of 3000-3500km, its propagation path spreading widely due to the refraction effect in the ionosphere.

The auroral observations carried out by the 11th wintering party of the Japanese Antarctic Research Expedition, 1970-1971, are ; 1. Photographic, observations of auroras with 16mm and 35mm all-sky cameras on routine basis. 2. Visual and photographic observations of auroras. 3. Observations of the space and time variations of proton auroras with the H_β tilting-filter meridian-scanning photometer and electron auroras with the multicolor meridian-scanning photometers. 4. Observations of auroral pulsations with the zenith photometers. The principal aim of these observations is to study the dynamical morphology of proton and electron auroras during magnetospheric substorms. A high time-resolution scanning photometer was constructed to measure the H_β emissions in proton auroras. The equipment consists of the coelostat for scanning the sky along the geomagnetic meridian and the tilting-filter photometer for detecting the intensity and Doppler shift of the H_β emission. The scanning period of the coelostat was 45s, and the tilting period of the filter was 1s. The lower threshold of the detection was 0.25R/Å. In order to study the space and time variations of the electron flux and energy spectra of auroral electrons, observations with the multicolor meridian-scanning photometers were carried out. The scanning period of these photometers was 5s. The observed emission lines were N_2^+_λ4278, OI_λ5577 and OI_λ6300. The minimum detectable intensities of the photometers were 100R, 100R and 30R, respectively for these emissions. The photographic observations were carried out with an improved model of 35mm all-sky camera mounted with a fish-eye lens.