Search

エアロゾルゾンデとライダーを用いた成層圏エアロゾルの粒径分布,空間分布の観測を2002 03年と2007 08年の冬季に行った.2002 03年冬季は,ライダーにより10-15 kmの高度域で高い偏光解消度をもつエアロゾル層を検出した.その高度域で,エアロゾルゾンデ観測から導出したエアロゾルの有効半径は比較的大きい値(0.17-0.24 μm)を示した.気温は極成層圏雲が存在可能な温度よりも非常に高く,有効半径も大きいことから,エル・レベンタドール火山起源のエアロゾルの可能性が強いと思われた.2008年1月9日にライダーで観測した極成層圏雲の固体粒子と液滴粒子の温度履歴は,ほとんど同じ温度変化を示し,両者の違いは見られなかった.極成層圏雲の時間変化(空間分布),トラジェクトリー解析の結果から,グリーランドのような標高の高い地形効果による重力波等の影響により,小さい温度擾乱を受けた可能性を示唆していた., Balloon borne aerosol sonde observation and lidar observations were preformed at Ny-Alesund, Norway in the winters of 2002 03 and 2007 08. In the winter of 2002 03, the aerosol layers with the increment of depolarization ratio were observed at the lower stratosphere below 15 km height by lidar. The effective radius of stratospheric aerosol estimated from aerosol sonde observations showed high values of 0.17-0.24 μm in radius in the height range. The temperature in the height range was remarkably higher than the formation temperature of polar stratospheric cloud (PSC). The depolarized aerosol layer might be volcanic aerosol by the eruption of Mt. El Reventador. The average value of effective radius of stratospheric aerosol in the height range of 10-25 km was estimated to be 0.12 μm. In the winter of 2007 08, PSC events were frequently detected. Both solid and liquid PSC detected by lidar on January 9, 2008 showed that they experienced almost the same temperature history. They might be affected by meso-scale temperature perturbations such as gravity waves.

昭和基地(69゜00′S 39゜35′E)において,1997年4月～ 2008年1月まで,気球搭載光散乱式粒子計数装置(エアロゾルゾンデ)による75回の観測を実施し,地上から高度約30 kmまでの半径0.15-3.5 μmの領域の粒径分布の経年変化,季節変化等のデータを得た. 成層圏エアロゾルには,バックグランドエアロゾル層の秋から冬にかけての沈降,冬の極成層圏雲の活動,夏の極渦の崩壊に伴う成層圏エアロゾル層の復帰という季節変化などが見られ,経年変化の解析からは1991年のピナツボ火山噴火の影響が南極においても1999年頃まで残っていたことが示唆された. また,自由対流圏のエアロゾル濃度は,1-6月に比べて7-12月の濃度が有意に高いという季節変化を示した., This report summarizes observations of tropospheric and stratospheric aerosols by a balloon-borne optical particle counter (Aerosol sonde) performed at Syowa Station from April 1997 to January 2008. Typical seasonal changes in the stratospheric aerosol layer were characterized by sedimentations of the stratospheric aerosol layer in autumn, PSCs activity in winter, and sudden increase in aerosol concentration at the end of spring. The annual change shows that the perturbations of stratospheric aerosol caused by the eruption of Mt. Pinatubo in 1991 remained until 1999. Additionally, seasonal variation of tropospheric aerosol shows clear differences between concentrations from January to June and those from July to December.

北極ヘイズが頻繁に出現する春季(3-4月),清浄な大気へ変化する時期(5-6月)の北極対流圏内のエアロゾル粒子の組成とその混合状態の空間分布に関して知見を得るため,日本-ドイツ共同で航空機を用いたエアロゾル観測を2000年3-4月(ASTAR 2000)と2004年5-6月(ASTAR 2004)にスバールバル諸島周辺で実施した.春季には酸性状態の硫酸粒子が主要だったのに対し,夏季に移行する時期(6月)には中性の硫酸塩粒子(おそらく(NH_4)_2SO_4)の割合が増加していた.北極ヘイズ現象下ではススを含む粒子の割合が増加し,その多くは外部混合状態で存在していた.一方,バックグラウンド時(非北極ヘイズ時)には,スス粒子の割合は減少し,多くが硫酸(塩)粒子と内部混合した状態だった.ここでは,海塩粒子変質の鉛直変化や土壌粒子の空間分布についても報告を行う., Airborne aerosol measurements around the Svalbard Archipelago were carried out in March-April, 2000 (ASTAR 2000) and in May-June, 2004 (ASTAR 2004) for better understanding of the spatial distribution of aerosol constituents and their mixing states. Major aerosol particles were sulfate particles in both campaigns. In ASTAR 2000 (spring), acidic sulfate particles (mostly H_2SO_4 droplets) were dominant, whereas the relative abundance of neutralized sulfate particles (probably (NH_4)_2SO_4) increased in the transition period (ASTAR 2004). Under Arctic haze conditions, higher relative abundance of aerosol particles containing soot was observed. Most of the soot collected during the haze was present as "external mixing states". In contrast, soot dominantly existed as "internal mixture" with sulfate particles under the background (non-haze) conditions. In the transition period (June in ASTAR 2004), the relative abundance of aerosol particles containing soot decreased clearly. Vertical features of sea-salt modification and spatial distribution of mineral particles are also reported.

アークティックヘイズの特性を解明するためにおこなわれた3つの観測キャンペーン(ASTAR 2000,AAMP 2002,ASTAR 2004)で,エアロゾルの散乱係数,粒径分布などの航空機観測をおこなった.いずれのキャンペーンにおいてもエアロゾル粒子をステンレス製インレットから客室内に導入し,ディフューザーで減速後に各測定装置に分配した.エアロゾルの光学的散乱係数はアークティックヘイズ時,4000 m程度までの高度でそれ以上と際立った違いが認められた.これに対し,対流圏上層の散乱係数は,アークティックヘイズ期,清浄期でほぼ同じレベルであった.ヘイズ期にはエアロゾルの粒径分布は,清浄期のものよりも大きく,気塊が発生から長時間経っていることを示した. ヘイズ層の微細構造を明らかにするためおこなったカーテンフライトの結果,エアロゾルは等温位面を輸送されていることがわかった., Airborne aerosol measurements of the Arctic haze were carried out during three campaigns, Arctic Study of Tropospheric Aerosol and Radiation 2000 (ASTAR 2000), the Arctic Airborne Measurement Program 2002 (AAMP 2002) and ASTAR 2004. Aircraft used for the campaigns were Dornier for ASTAR 2000 2004 and Gulfstream II for AAMP 2002. For all measurements aerosol particles were introduced into the cabin through stainless inlets and distributed to several instruments via a diffuser. Scattering coefficient of aerosol particles measured with an integrating nephelometer during the Arctic haze period showed a distinct difference between the lower, i.e. up to around 4000 m, and higher troposphere. Meanwhile, scattering coefficients in higher troposphere during the Arctic haze were in the same degree with those after the Arctic haze. Size distribution obtained from the data of a particle counter indicates that aerosol particles in accumulation mode during the Arctic haze have larger geometric mean diameter than those after the haze season, which reflects the aged air mass in the Arctic haze. "Curtain flight" which was carried out to reveal the fine structure of the haze layer showed that aerosol particles are transported in the isentropic plane.