著者

ワダ マコト アオキ シュンジ セコ カツモト マツバラ コウジ ドイ モトヒサ ウエクボ テツロウ オカダ ケンジ カワグチ サダオ Makoto WADA Shuhji AOKI Katsumoto SEKO Kouji MATSUBARA Motohisa DOI Tetsuro UEKUBO Kenji OKADA Sadao KAWAGUCHI

雑誌

Proceedings of the NIPR Symposium on Polar Meteorology and Glaciology

巻号頁・発行日

vol.4, 1991-05

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A 5-year project of "Antarctic Climate Research (ACR)" has been started from JARE-28 in 1987. Observations of clouds and precipitation were carried out using vertical pointing radar and two microwave radiometers in 1988 (JARE-29), the second year of this project. The observations of vertical pointing radar were begun on February 24,1988,and the microwave radiometers observations were handed over to JARE-29 by JARE-28 on February 1,1988. The characteristics of the precipitation in 1988 at Syowa Station, on the coast of Antarctica, are described in this paper. Ten days variation of precipitation are calculated using radar echo intensity at 300m altitude and the relation between radar reflectivity factor (Z) and rainfall rate (R), the so-called Z-R relation. The values obtained from this method are free from the contamination of drifting snow which affects precipitation obtained by rain gauge. The result shows the maximum precipitation in autumn (February and March) and the minimum precipitation in spring (September and October). Low precipitation in spring seems to be characteristic of 1988 at Syowa Station. Snow crystals of precipitation there can be classified into three types : graupel or a heavily rimed crystals, grathering bullets, and other types of crystals such as snowflakes, dendrites and plates. The first and second types of crystals were mainly observed throughout 1988. The height of the radar echo was relatively low; namely, the echo top was under 2km in altitude, in the period when the first type of crystals mainly fell. On the other hand, in the period when the second type of crystals mainly fell, the echo top was often over 4km altitude.

著者

牧野 行雄 塩原 匡貴 村松 久史 川口 貞男 山内 恭 田中 正之 小川 利紘 増谷 浩二 森井 正夫 Yukio Makino Masataka Shiobara Hisafumi Muramatsu Sadao Kawaguchi Takashi Yamanouchi Masayuki Tanaka Toshihiro Ogawa Koji Masutani Masao Morii

雑誌

南極資料 (ISSN:00857289)

巻号頁・発行日

vol.87, pp.1-22, 1985-12

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南極中層大気の総合観測(Antarctic Middle Atmosphere Program)の一環として, 南極昭和基地において1983年3月24日から1984年12月29日まで(第24次および第25次南極地域観測隊)太陽光の赤外分光測定による大気微量成分(N_2O, CH_4,CFCl_3,CF_2Cl_2,HNO_3)の観測を行った。使用した分光計の分解能は最高0.1(cm)^<-1>まで設定可能であるが, 観測時間の長さやS/N比を考慮して0.8(cm)^<-1>で通年観測を行った。延べ111日間に計487個のスペクトルを得たが, これらは最終的に磁気テープに記録し大型電子計算機で処理する。測定されたスプクトルのS/N比から, CFCl_3(850(cm)^<-1>), N_2O(2576(cm)^<-1>), CH_4(6004(cm)^<-1>) のカラム密度は, それぞれ±40,±2,±6%の測定誤差を有することが見積もられる。特に1000(cm)^<-1>域のより精密な測定のために, 今後, 高感度検知器(MCTなど)の安定な使用による観測が望まれる。As part of the Japanese Antarctic Middle Atmosphere Program (Antarctic MAP), columnar amounts of atmospheric minor constituents such as N_2O, CH_4,CFCl_3,CF_2Cl_2 and HNO_3 were determined from measurements of infrared solar spectra for the period 24 March 1983-29 December 1984 at Syowa Station, Antarctica (69°00′S, 39°35′E). A Fourier-transform-infrared spectrometer was used to measure the solar spectra. The highest apodized resolution of the spectrometer is 0.1(cm)^<-1> (full width at half-maximum), but the resolution of 0.8(cm)^<-1> was adopted in routine operation because of an economy of data processing time and of better signal to noise (S/N) ratio. The accuracy of measurements is estimated from S/N ratios of the obtained spectra; typical errors of measured abundances were ±40,±2 and ±6% for CFCl_3 (at 850(cm)^<-1>), N_2O (at 2576(cm)^<-1>) and CH_4 (at 6004(cm)^<-1>), respectively. A MCT detector (cooled at 77 K) is desirable to attain higher resolutions (&acd;0.1(cm)^<-1>) and larger S/N ratios.