研究者詳細 - 長田　和雄

論文 - 長田　和雄

分割表示 144 件中 101 - 120 件目／全件表示 >>

Observations of atmospheric aerosol particles over the Antarctic Ocean by ocean research vessels

Osada, Kazuo, Hara, Keiichiro, Yabuki, Masanori, Nishita-Hara, Chiharu, Kobayashi, Hiroshi, Miura, Kazuhiko, Ueda, Sayako, Hayashi, Masahiko, Hashida, Gen, Shiobara, Masataka, Wada, Makoto, Yamanouchi, Takashi

Antarctic Record 54 巻 ( Sp. Iss. SI ) 頁： . 2010年

昭和基地で観測された大気エアロゾル中の金属成分および炭素成分の季節変動

小林拓, 原圭一郎, 塩原匡貴, 山内恭, 長田和雄, 太田幸雄

南極資料頁： 54, 554-561 2010年

南極沿岸域でのブラックカーボン－季節変化と輸送過程

原圭一郎, 長田和雄, 矢吹正教, 林政彦, 山内恭, 塩原匡貴, 和田誠

南極資料頁： 54, 562-592 2010年

南極・昭和基地におけるサブミクロン粒子粒径分布の季節変化

長田和雄, 西田千春, 原圭一郎, 矢吹正教, 塩原匡貴, 和田誠, 山内恭, 林政彦

南極資料頁： 54, 530-540 2010年

南極対流圏中の超微小粒子の揮発特性とその季節変化

原圭一郎, 長田和雄, 西田千春, 矢吹正教, 林政彦, 山内恭, 和田誠, 塩原匡貴

南極資料頁： 54, 541-553 2010年

*Impact of Chinese anthropogenic emissions on submicrometer aerosol concentration at Mt. Tateyama, Japan 査読有り

K. Osada, T. Ohara, I. Uno, M. Kido and H. Iida

Atmospheric Chemistry and Physics 9 巻頁： 9111-9120 2009年12月

乗鞍岳における大気エアロゾルの観測-粒子数粒径分布の変化とその要因招待有り査読有り

西田千春・長田和雄，

エアロゾル研究 24 巻頁： 105-111 2009年6月

Global distribution and seasonal concentration change of methyl iodide in the atmosphere 査読有り

Yokouchi, Y., K. Osada, M. Wada, F. Hasebe, M. Agama, R. Murakami, H. Mukai, Y. Nojiri, Y. Inuzuka

J. Geophys. Res. 113 巻 ( D18311 ) 頁： doi:10.1029/2008JD009861 2008年9月

Factors controlling sea salt modification and dry deposition of non-sea-salt components to the ocean 査読有り

Kawakami, N., K. Osada, C. Nishita, M. Yabuki, H. Kobayashi, K. Hara, and M. Shiobara

J. Geophys. Res. 113 巻 ( D14216 ) 頁： doi:10.1029/2007JD009410 2008年7月

Nucleation mode particles in up-slope valley winds at Mt. Norikura, Japan: implications for the vertical extent of new particle formation events in the lower troposphere 査読有り

Nishita, C., K. Osada, K. Matsunaga, Y. Iwasaka

J. Geophys. Res. 113 巻 ( D06202 ) 頁： doi:10.1029/2007JD009302 2008年3月

Preferential settling of elongated mineral dust particles in the atmosphere 査読有り

GEOPHYSICAL RESEARCH LETTERS 34 巻頁： doi:10.1029/2007GL030262, 2007 2007年9月

*Temporal variation of water-soluble ions of free tropospheric aerosol particles over central Japan 査読有り

Tellus 59B 巻頁： 742-754 2007年8月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

Free tropospheric aerosol particles were collected at Mt. Norikura (36.1°N, 137.5°E, 2770 m a.s.l.) in Japan during May–October in 2001 and 2002. An automated sequential daily nighttime (00–06 a.m.) sampler collected free tropospheric aerosols. Average, median, SD, minimum and maximum concentrations of total ionic weight of the 114 samples were, respectively, 3.9, 2.8, 3.7, 0.2 and 23.2 μg m3. Transport conditions were analysed using backward air trajectory with precipitation amounts along the trajectory. Results suggest that low aerosol mass concentration causes are (1) descending trajectories and (2) precipitation scavenging during transport without contacting boundary layer atmosphere until arrival. It is suggested that, without precipitation scavenging after entrainment into the free troposphere, aerosol transport from active emissions at the surface enhances mass concentration at Mt. Norikura.

Average concentrations of NO3, non-sea-salt (nss)K+ and C2O42 are high in March–June and low in winter. The highest average nssSO42 concentration occurs in summer; it is high from spring through fall. Seasonal variation of NH4+ concentrations resembles that of nssSO42, but the concentrations' molar ratio (NH4+/nssSO42) is high (ca. 2) in spring and decreases to 1 in winter. Seasonal variation of NH4+ + NH3 concentration agrees with that of NH3 emissions in China.

黄砂招待有り査読有り

長田和雄

天気 54 巻 ( 8 ) 頁： 697-700 2007年8月

Number-size distributions of free tropospheric aerosol particles at Mt. Norikura, Japan: effects of precipitation and air-mass transportation pathways 査読有り

Nishita, C., K. Osada, K. Matsunaga, Y. Iwasaka

J. Geophys. Res. 112 巻頁： doi:10.1029/2006JD007969, 2007 2007年5月

記述言語：英語掲載種別：研究論文（学術雑誌）

Number-size distributions of free tropospheric aerosol particles of 9–300-nm diameter were observed at Mt. Norikura (36.1°N, 137.5°E, 2770 m a.s.l.) in central Japan in August and September 2002. We observed two distinct air masses transported from over the Pacific Ocean and continental Asia. Size distributions of aerosol particles were analyzed in terms of their relation to the air mass transportation pathway, cumulative precipitation amount in the air mass for the last 24 h, and local precipitation rate. Particle concentrations of the accumulation mode range (100–300 nm) decreased by an order of magnitude when cumulative precipitation amount increased from 0 to 20 mm. The cumulative precipitation amount is suggested as an important factor to modify the size distribution by decreasing particle concentration. Considering data for air masses without experience of precipitation scavenging before arrival, concentrations of accumulation mode particles were almost identical (approximately 400 cm−3) in air masses transported from over the Pacific Ocean and continental Asia. Concentration of Aitken mode particles was high (890 cm−3 as a median value) in the air mass subsiding from over the subtropical Pacific Ocean (> 4 km a.s.l.). Based on the relationship with the controlling factors described above, this study provides number-size distribution parameters of free tropospheric aerosol particles in the west Pacific area.

Water-insoluble particles in spring snow at Mt. Tateyama, Japan: Characteristics of the shape factors and size distribution in relation with their origin and transportation 査読有り

Li, Jingmin and K. Osada

J. Meteorol. Soc. Jpn 85 巻頁： 137-149 2007年4月

記述言語：英語掲載種別：研究論文（学術雑誌）

The number-size distribution and shape factors of water-insoluble particles (WIP) in four dirty snow layers in the spring of 2001 at Mt. Tateyama, Japan, were analyzed using scanning electron microscopy, and using optical microscopy with a digital camera. Results show that the median aspect ratio (ratio of the longest dimension b to the orthogonal width a; b/a) of the WIP varied within 1.22-1.31. Only a few particles with an aspect ratio of more than 2.5 were observed. The median circularity factor (4πS/l2; S is projection area, and l is periphery length) varied from 0.83-0.97.
Combined with backward air trajectories, visibility reducing surface weather reports, additional results of rain containing Saharan dust and dry deposition samples, the number and shape factor distributions versus particle size were characterized as (1) narrower distributions of number-size and shape factors for the Saharan dust, and (2) bi-modal number-size distribution for dry deposited dust. Results suggest that the proportions of nearly spherical (higher circularity nearly 1) and less elongated (lower aspect ratio close to 1) particles were higher in the sample that had been transported a longer distance from the dust source areas.

Lower Tropospheric Vertical Distribution of Aerosol Particles over Syowa Station, Antarctica from Spring to Summer in 2004 査読有り

Osada, K., K. Hara, M. Wada, T. Yamanouchi, K. Matsunaga

Polar Meteorol. Glaciol 20 巻頁： 16-27 2006年12月

Aerosol constituents and their spatial distribution in the free troposphere of coastal Antarctic regions 査読有り

Hara, K., Y. Iwasaka, M. Wada, T. Ihara, H. Shiba, K. Osada, T. Yamanouchi

J. Geophys. Res 111 巻頁： doi:10.1029/2005JD006591 2006年8月

Spatial distributions of volatile sulfur compounds in surface seawater and overlying atmosphere in the northwestern Pacific Ocean, eastern Indian Ocean, and Southern Ocean 査読有り

Inomata, Y., Hayashi, M., Osada, K., Iwasaka, Y.

Global Biogeochemical Cycle 20 巻頁： doi:10.1029/2005GB002518 2006年6月

Vertical distributions of particles and sulfur gases (volatile sulfur compounds and SO2) over East Asia: Comparison with two aircraft-borne measurements under the Asian continental outflow in spring and winter 査読有り

Y. Inomata, Y. Iwasaka, K. Osada, M. Hayashi, I. Mori, M. Kido, K. Hara, T. Sakai

Atmospheric Environment 40 巻頁： 430-444 2006年1月

Variations of constituents of individual sea-salt particles at Syowa station, Antarctica 査読有り

57B 巻頁： 230-246 2005年

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