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An image data processing system has been developed in order to analyze auroral conjugacy of auroral positions, shapes and motions. The new system has the following advantages : 1) A large amount of image data can be quickly and efficiently analyzed by using the system. 2) The geomagnetic coordinate display and auroral dynamic display produced by the system are useful for comparison of auroral positions, shapes and motions between two hemispheres. 3) The smooth combination techniques of auroral image data make it possible to investigate auroral conjugacy with wider field of view than that of one station. The developed processing system is applied to conjugate auroral TV camera data of September 9-10,1991 events observed at Syowa and Asuka stations, in Antarctica and Husafell in Iceland.

Average energy and total energy flux of the incident electrons in active auroras are estimated by using the intensity ratio of auroral emissions measured with a multi-channel photometer at Syowa Station, Antarctica, in 1990. To avoid possible ambiguities which are mainly caused by quenching effects on meta-stable species and complex excitation processes, we used intensity ratios of the emissions of allowed transitions such as 844.6nm (OI), 670.5nm (N_21PG), and 427.8nm (N_2^+1NG). Measured intensity ratios were directly compared with a result of model calculation of auroral emissions. The estimated energy parameters in active auroras showed a rapid change of average energy as well as total energy flux of electrons associated with pulsating auroras and intense auroral arcs. Average energy and total energy flux of the auroral electrons determined by the present method were consistent with the result of the previous in-situ observations of precipitating electrons. Our data analyses on active arcs in break-up phase showed that usage of the 427.8nm emission has difficulty due to a scattering effect of the atmosphere. Usage of 670.5nm emission in place of 427.8nm made it possible to evaluate the energy parameters of electrons even in the vicinity of intense auroral arcs.

LHR (lower hybrid resonance) whistlers have been found in the mid-latitude records from a bioadband VLF receiver aboard the EXOS-A satellite. Characteristics of the LHR whistlers are the successive enhancement of dispersion and the frequency resonance, in the vicinity of the local LHR frequency. The resonance phenomenon of the LHR whistlers has been interpreted as a nonducted propagation of whistler-mode waves with a large wave normal angle in the magnetospheric plasma, whose density gradient is pearly perpendicular to the earth's magnetic field

Twenty-nine members of the wintering party occupied Syowa Station from February 1,1976 to January 31,1977,carrying out the preparation and observations in accordance with the program of the first year of research projects of the International Magnetospheric Study (IMS). At Syowa Station, in addition to the observation of aurora, geomagnetism, ionosphere, meteorology, seismology, marine morphology, ocean tide, and medical science, the major research program covers the preparation of many observation apparatuses for upper atmosphere physics, as well as the construction of satellite tracking and telemetry facilities, the reception of telemetry signals from scientific satellites, and the launching of seven (five in winter) sounding rockets and one big balloon to carry out the IMS project. Mizuho Station was improved for upper atmospheric observations in connection with the IMS program including the construction of one observation hut and the setting up of a 16kVA generator in May 1976,and occupied by four members in rotation so as to carry out observations of upper atmosphere physics, glaciology, and meteorology from May 14,1976 to January 26,1977.

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.

The objective of this paper is to show the main aspects of Japanese program to stablish an effective and reliable system to inter and intra-continents communication network for data and information transmission, to collect meteorological and geophysical data from Antarctica by the remote sensing system at present and in the near future. The difficulties to obtain environmental data from the, Antarctic territory are well known. The employment of earth orbiting satellites appears specially adequate to clarify several aspects related with this problem. The global system comprises geostationary and polar orbiting satellites to obtain qualitative and quantitative data, derived from imagery and automatic ground-based sensing stations (unmanned) called Data Collection Platforms (DCPs).

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.

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.

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.

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

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.

POLEX program, as a sub-project of GARP, will start the 3 years' observation from 1979. And MAP will be opened from 1982. Based on these projects, the 21 st Japanese Antarctic Research Expedition will be set up with the meteorological satellite tracking and telemetry system at Syowa Station in Antarctica, and will receive the information of surface temperature, cloud, ozone and vertical temperature profiles. The analytic result of described information will make clear the circulation of the atmosphere, sudden warming in the spring, structure of a high latitude atmosphere, and the influence of middle upper atmosphere in the polar region affecting the general circulation of the earth's atmosphere.

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.

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

The IMS satellite EXOS-A (1978-014A) launched into a quasipolar eccentric orbit on February 4, 1978, includes in its payload a plasma wave detector, which has one broadband channel and eleven bandpass channels covering the frequency range 400 Hz to 3 MHz Each channel is connected to an electric dipole antenna and two Faraday cups Since thc Faraday cup responds to electron density fluctuation only, examination of sensor dependence of the detected wave spectra allows electrostatic and electromagnetic waves to be distinguished The present note gives a gist of the EXOS-A plasma wave experiment and related instrumentation

第3次越冬においては,(1)1年無保守状態のまま放置された機器の回復と,(2)空輸のため燃料節約を必要とし,(3)多くの観測機械が設置されるため,電圧変動,三相発電機の相間バランス,各相の力率変動を極力防止する必要があった.そのため各部門の使用電力量,使用時間を規制し送電系統を並列に改めて負荷の調整を行なった結果,各棟約5KWの負荷時の入力端子間電圧降下は約0.5V以内に改められた.20KVA発電機の燃費は上記の規制に隊員の協力を得て予想以上の節約ができた.運転時間は1号が5479時間,2号は3116時間で非常に良好に保守され機器の故障は皆無,送電停止時間は計11分30秒,発電機関係の補用品も充分量保有している.発電量は年平均1日134.2KVA,燃費は80.7lであった.小型発動発電機類も飛雪に対する注意と燃料内の氷晶除去に留意すれば低温下でも容易に運転できた.450WDC発電機が雪上車のAPUとしても最も使用され,特に-40℃以下の雪上車の起動に際しあらかじめ本機でバッテリーに30Aの充電電流を約5分間流すことにより,予熱の必要なく安全に一気に起動できた.その他フィールド用として1KVA,350WAC発電機も使用した.バッテリーは電解液の比重低下したものが液凍結によって破損したものがある.高比重(1.35/-30℃以上)に保つことが必要である.電気関係の諸機器は非常に良好な状態に保たれ,適切な保守によって相当長期間の使用に耐え得る.

Acoustical noises in two diesel-engine driven KD60 oversnow vehicles (KD607 with all-over cab and KD608 with cab only over driver's seat) to be used by the 10th Japanese Antarctic Research Expedition (1968-1970) were measured in October 1968, during the test run of vehicles (inside and outside) and during the idling (inside), on volcanic deposits at the foot of Mt. Fuji. Instrument used is an Impulse Precision Sound Level Meter (type 2203 made by Bruel and Kjaer, in Denmark). The noises were measured when the engine was operating at 1500-2400 rpm at a speed of 10-18 km/h during the test run, and at 600, 1000, 1500, 2000 and 2400 rpm during the idling. There are five measuring spots inside the KD607 and one spot outside, and two spots inside the KD608. The maximum noise levels of running KD607, represented by A-Scale of the Level Meter, are 93dB inside the cabin and 96dB outside, and 100dB in KD608. The maximum noise levels when idling the engine at 2400 rpm are 81.5dB and 86dB in KD607 and KD608, respectively. The noise intensity inside the cabin during the running is below safe level given by the International Organization for Standardization, Technical Committee 43 ; Acoustics, except in the domain of low frequency. Ordinary conversation with somewhat loud voices is possible during the idling, but when the vehicles is running only shouts are audible.

1.目的 オーロラが出現したとき,その部分の高層大気中に局部的に電子密度の高い領域があると考えられている.その高電離気体から輻射される電波の性質を知ることはオーロラの発光機構を説明する一つの手ががりとなるので,或る角度に向け固定されたパラボラアンテナと3000MCの受信機によりノイズレベルを連続記録し,他部門のデータと比較研究する.2.結果 今回は記録装置に打点式を使用したこと,基地内部のノイズレベルが予想外に高かったため,必ずしも満足なデータを得られなかったが,オーロラおよび擾乱を受けた高層大気から輻射される3000MC帯の電波の存在が大略実証され,その地磁気,オーロラ強度,E_s電離層の突抜周波数の急変との相互相関もかなり良く,その詳細なる解析を続行中である.

1.目的 万年雪,高圧気泡入氷からできた氷冠域において,雪氷の高周波誘電特性雪,表面の電波の反射吸収特性,比抵抗等を測定することにより,極地方の氷冠内における電波伝播特性の解析,氷冠上にて使用するアンテナの設計,通信回線の設計等のための資料を得ることを目的とし,1.5,10,100,250,300,400,3000Mcの各周波数毎に,(1)容量置換法,レッヘル線により,誘電率,誘電体損(tanδ)を,(2)ハイトパターン法により反射,吸収係数を,コーラウシュブリッジにより比抵抗を測定し,数種のアンテナにより通信を行ない電界強度を測定した.また気温逆転層による300,3000Mcのフェーディング特性,万年雪にまい没したアンテナと空間のアンテナとのインピーダンス,指向性パターン等も測定した.2.結果 実測の結果,万年雪および氷冠氷の比誘電率の値は非常に小さく,周波数の増加,密度の減少とともに減少する.誘電体正切特性の値も非常に小さく,周波数の増加とともに激減する.反射係数もHF帯では小さく,周波数の増加とともに増加する,従って氷冠の雪氷上で使用するアンテナは表面の雪の比誘電率が1に非常に近いので,雪面上に直接導線を置くだけの非常に簡単なアンテナで,ほぼ自由空間とみなし得る輻射が得られることが解り,秋春の大陸旅行において実証することができた.なお,測定に使用した機器は昭和基地にて製作したため帰国後検定中であり,期日の都合で今回は現在までに得られた較正データのみ中間報告として発表する.海氷上の電波伝播はVHF以下の周波数帯では大略海水面と同じ特性を示し,UHF以上はその表面の状態(氷,雪)の影響が大きい.なお偏波面は氷冠上が水平,海氷上は垂直が良いようであった.

第3次越冬は空輸によったため,越冬開始に当り226本の発電機用軽油の消費規正を行い,予備46本とし,年間使用量を180本と決め,各部門の電力使用量,時間等を規正して1日当り使用量を夏85l,春秋95l,冬110lと決めたが,隊員の協力により夏平均76.5l,冬平均83.1l,年平均80.7l,年間使用量157本の実績であった.雪上車用ガソリンの低温対策としては旅行出発前に全燃料中に含まれる氷晶を厚手ナイロン地でフィルトし,飛雪の混入を防止して解決した.ソ連ガソリンに比較して日本製ガソリンには氷晶の混入がはるかに多い.