ダイ49ジ ニホン ナンキョク チイキ カンソクタイ キショウ ブモン ホウコク 2008

この報告は第49次日本南極地域観測隊気象部門が,2008年2月1日から2009年1月27日までの越冬期間中に昭和基地において行った気象観測結果をまとめたものである.観測方法・測器・統計方法などは第48次隊とほぼ同様である. 越冬期間中,特記される気象現象として,次のものが挙げられる. 1)9月1日,175 hPaから上層のすべての気圧面で,9月としての最低気温の極値を更新した. 2)地上気象観測において,10月の平均気温は-17.5°Cと低く,これまでの平均値として最も低い極値(2007年までの記録は1991年10月の-16.1°C)を更新した. 3)昭和基地上空のオゾン全量は,8月下旬から11月下旬までオゾンホールの目安となる220 m atm-cmをほぼ継続的に下回った.特に9月中旬から10月中旬にかけてオゾン全量が非常に少なく,10月16日には2008年でも最小値である140 m atm-cmを記録した (2007年までの最小値は2006年10月17日の114 m atm-cm).This report describes the result of meteorological observations at Syowa Station by the Meteorological Observation Team of the 49th Japanese Antarctic Research Expedition (JARE-49) during the period 1 February 2008 to 27 January 2009. The observation methods, instruments, and statistical methods used by the JARE-49 team are nearly the same as those used by the JARE-48 observation team. Remarkable weather phenomena observed during the period of JARE-49 are as follows. 1) On 1 September 2008, the record minimum temperature for September was observed in the upper atmosphere (pressure greater than 175 hPa). 2) The monthly mean temperature at Syowa Station during October 2008 was -17.5°C; this is the lowest monthly mean October temperature recorded at Syowa Station. 3) The total ozone over Syowa Station was less than or equal to 220 m atm-cm during the period from late August to late November, and was close to minimum levels during the period from mid-September to mid-October. The lowest total ozone in 2008, recorded on 16 October 2008, was 140 m atm-cm

コガタ クライオサンプラー ヲ モチイタ ショウワキチ デノ セイソウケン タイキ サイシュ ジッケン ダイ49ジタイ ジッケン ホウコク

第49次南極地域観測隊(第49次隊)夏期間に昭和基地において,新たに開発した小型クライオサンプラーを用いた成層圏大気採取実験を実施した.小型クライオサンプラーは高圧ネオンガスを断熱膨張させて液体ネオンを製造し,希薄な成層圏大気を固化・液化採取するものであり,既存の大型サンプラーが必要とした液体ヘリウムが不要であること,小型軽量であるために満膨張時容積1000-2000 m3の小型プラスチック気球を用いて成層圏まで飛揚させることが可能であるという特徴がある.2007年12月30日と2008年1月4日に計4機の小型サンプラーを放球し,すべて回収に成功した.そのうち,2機は高度18 km及び25kmの成層圏大気の採取に成功した.採取された大気試料は国内に持ち帰られた後,各種温室効果気体濃度と同位体比の分析が行われた.As a part of summer observations of the 49th Japanese Antarctic Research Expedition, stratospheric whole air sampling experiments were conducted at Syowa Station using newly developed compact cryogenic air samplers. The compact sampler uses liquefied neon (produced in-situ) as a refrigerant to solidify or liquefy atmospheric constituents. Because of its reduced size and weight, the sampler can be launched using small-size balloons (1000–2000 m3 in volume). On December 30, 2007 and January 4, 2008, a total of 4 samplers were launched from Syowa Station and recovered on the same day as their launches. Two of them functioned as designed and collected stratospheric air samples at altitudes of 18 and 25 km. The air samples were analyzed for greenhouse gas concentrations and stable isotopes after return to Japan

Meteorological observations at Syowa Station and Dome Fuji Station in 1995 by the 36th Japanese Antarctic Research Expedition

This paper describes the results of meteorological observations carried out by the Meteorological Observation Team of the 36th Japanese Antarctic Research Expedition (JARE-36) from 1 February 1995 to 31 January 1996 at Syowa Station and Dome Fuji Station. The first overwintering team at Dome Fuji Station had conducted year-round surface synoptic observations under extremely cold conditions that had not been experienced by any other Japanese projects before. The method of observations, instruments and statistical calculation at Syowa Station were the same as those of the JARE-35 observation team. At Dome Fuji Station, similar surface observation techniques were used. The principal topics in the period of JARE-36 were as follows. 1) In the "A" class blizzard which hit Syowa Station in October, 49.0m/s maximum gust wind speed was recorded, the strongest for October in history. 2) An Antarctic ozone hole of large scale was observed for the seventh successive years at Syowa Station. The lowest daily total ozone was 128m atm-cm on 6 October 1995,the lowest in the historical record of Syowa Station. 3) The lowest temperature of -79.6℃ for this period was marked on 18 August 1995 at Dome Fuji Station, the lowest in the history of the Japanese Antarctic Research Expedition

Meteorological observations at Syowa Station, Antarctica, 2008 by the 49th Japanese Antarctic Research Expedition

This report describes the result of meteorological observations at Syowa Station by the Meteorological Observation Team of the 49th Japanese Antarctic Research Expedition (JARE-49) during the period 1 February 2008 to 27 January 2009. The observation methods, instruments, and statistical methods used by the JARE-49 team are nearly the same as those used by the JARE-48 observation team. Remarkable weather phenomena observed during the period of JARE-49 are as follows. 1) On 1 September 2008, the record minimum temperature for September was observed in the upper atmosphere (pressure greater than 175 hPa). 2) The monthly mean temperature at Syowa Station during October 2008 was -17.5°C; this is the lowest monthly mean October temperature recorded at Syowa Station. 3) The total ozone over Syowa Station was less than or equal to 220 m atm-cm during the period from late August to late November, and was close to minimum levels during the period from mid-September to mid-October. The lowest total ozone in 2008, recorded on 16 October 2008, was 140 m atm-cm

RADIO SONDE TEMPERATURE MEASUREMENTS AT DOME FUJI STATION, ANTARCTICA

Upper air observations using an omega sonde system (RS80-15P : VAISALA) were carried out at Dome Fuji Station from November 7,1995 to January 3,1996. The total number of launched omega sondes was 22. Wind data could not be obtained, because VLF radio waves from omega stations could not be received at Dome Fuji Station. Seven omega sondes reached the tropopause, but the others failed due to problems with the sondes or the receiving apparatus. The average maximum height the sonde reached was about 8km above sea level. A remarkable inversion layer was found with 21 observations. The maximum temperature difference between the top and bottom of the layer was 17.8℃. The mean thickness (ΔH) of the inversion layer was 256m and the mean temperature difference (ΔT) between the top and bottom of the layer was 6.8℃. The observations show that ΔT is largest between 03 LT and 09 LT, and ΔH is thinnest between 21 LT and 03 LT

YEAR-ROUND SURFACE SYNOPTIC OBSERVATIONS AT DOME FUJI STATION, EAST ANTARCTICA CONDUCTED BY THE FIRST OVERWINTERING PARTY

The 36th Japanese Antarctic Research Expedition (JARE-36) commenced surface synoptic observations at Dome Fuji Station, East Antarctica on 11 February 1995 as a part of the Deep Ice Coring Project at Dome Fuji, East Antarctica (the fourth year). The first overwintering team at the Dome Fuji Station conducted year-round surface synoptic observations under extremely cold weather conditions which had not been experienced by any other Japanese project before. Synoptic observation data of surface pressure, temperature, wind direction, wind speed and flux of global solar radiation were automatically recorded every one minute. These automated observation data were obtained without trouble throughout the overwintering period. This was made possible by development of special instruments protected against frost and snow accretion, which had been the major difficulty in automated observation in the antarctic area. Visibility, total cloud amount, cloud forms, atmospheric phenomena and present weather conditions were visually observed everyday at 09,15 and 21 o\u27clock in local time. We obtained these visual observations year-round at Dome Fuji Station for the first time. During our one-year stay at the Station, from March 1995 to February 1996,an annual mean temperature of -53.9℃ was observed. The lowest temperature of -79.6℃ for this period was marked on 18 August 1995. Annual mean surface pressure was 598.2hPa and annual mean wind speed was 5.8m/s. Except in summer, a rather strong wind speed of about 6m/s was steadily observed throughout the year and the gust ratio was very small. That was a distinctive characteristic of the wind at the Dome Fuji Station. No prevailing wind direction was observed at the Station. The most frequent surface wind direction of each month corresponded well with the monthly averaged geostrophic wind direction at 500hPa height. Annual mean total cloud cover was about 40%. High cloud was dominant even in the case of cloudy weather. Ice prisms (diamond dust) were observed almost every day. Details of the observed data were published in the Antarctic Meteorological Data of the Japan Meteorological Agency in 1995. Details of the surface synoptic observations including accuracy of the measuring instruments at the Dome Fuji Station will be summarized in the Antarctic Report to be published by the National Institute of Polar Research

Stratospheric whole air sampling experiments at Syowa Station with compact cryogenic air samplers in JARE-49

As a part of summer observations of the 49th Japanese Antarctic Research Expedition, stratospheric whole air sampling experiments were conducted at Syowa Station using newly developed compact cryogenic air samplers. The compact sampler uses liquefied neon (produced in-situ) as a refrigerant to solidify or liquefy atmospheric constituents. Because of its reduced size and weight, the sampler can be launched using small-size balloons (1000–2000 m3 in volume). On December 30, 2007 and January 4, 2008, a total of 4 samplers were launched from Syowa Station and recovered on the same day as their launches. Two of them functioned as designed and collected stratospheric air samples at altitudes of 18 and 25 km. The air samples were analyzed for greenhouse gas concentrations and stable isotopes after return to Japan