二次粒子生成・成長に与えるPM<sub>0.1</sub>中炭素成分および金属成分の寄与調査  [in Japanese] Survey on Contribution of Carbon and Metal Components in PM<sub>0.1</sub> to Secondary Particle Formation and Growth  [in Japanese]

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Abstract

<p>大気中微小粒子の挙動調査を目的として、一般大気環境下において2014年から2015年の各四季においてPM<sub>0.1</sub>とPM<sub>2.5</sub>の粒径別大気捕集を昼夜別に行い、炭素成分と金属成分の分析を行った。気象データを考慮した日挙動の濃度変化の結果から、PM<sub>0.1</sub>とPM<sub>2.5</sub>に含まれる各成分はともに風向や日照の影響を受け、粒子濃度や成分濃度は捕集地点周辺の局地発生源や気象の影響により変化することが確認された。PM<sub>0.1</sub>とPM<sub>2.5</sub>の粒子径比率により、一年を通して大きな発生源寄与を一定の割合で受ける成分と、様々な発生源寄与を受けるために季節によって異なる比率を示す成分とが存在した。また、粒子生成における光化学反応の寄与はPM<sub>0.1</sub>に大きく、粒子生成および成長における凝縮作用の寄与はPM<sub>2.5</sub>に大きいことが示唆された。スピアマンの順位相関係数をとったころ、夏季のように光化学反応が顕著な条件での粒子生成では、有機炭素成分自身が自己凝縮を起こして粒子化している可能性が示唆された。これに対し、気温や混合層高度の低下に伴う凝縮や凝集といった作用が起こりやすい冬季においては、大気中に存在する金属成分を核として有機炭素成分が粒子生成や粒子成長を起こしている可能性が示唆され、全ての季節の夜間においても同様の傾向が見られた。</p>

<p>Each size collection and analysis of carbon and metal components in the PM<sub>0.1</sub> and PM<sub>2.5</sub> were performed by day and night at a suburban site in each season from 2014 to 2015. Based on the results of daily behavior, it was confirmed that the components in the PM<sub>0.1</sub> and PM<sub>2.5</sub> were influenced by the weather conditions, and daily variation of those concentrations were influenced by the local emission sources and weather conditions. The ratios of the components in the PM<sub>0.1</sub> and PM<sub>2.5</sub> indicated two different concentration patterns of the components. One received a large source contribution through the year at a constant ratio, and the other received various source contributions in each season. Therefore, the latter showed different ratios in each season. Furthermore, it was suggested that the contribution of the photochemical reaction was greater for PM<sub>0.1</sub> and the condensation effect was greater for PM<sub>2.5</sub>. In the case of the particle formation of PM<sub>0.1</sub> which was strongly affected by the photochemical reaction, the organic components contributed to the secondary particle formation by self-condensation, especially in the summer. On the other hand, in the case of particle formation of PM<sub>2.5</sub>, which was strongly affected by the condensation and coagulation with the decreasing temperature or mixing layer, the metal components affected the condensable particle formation and growth as nuclei particles by mixing the organic carbon components, especially in the winter.</p>

Journal

  • Journal of Japan Society for Atmospheric Environment / Taiki Kankyo Gakkaishi

    Journal of Japan Society for Atmospheric Environment / Taiki Kankyo Gakkaishi 52(1), 30-39, 2017

    Japan Society for Atmospheric Environment

Codes

  • NII Article ID (NAID)
    130005450380
  • Text Lang
    JPN
  • ISSN
    1341-4178
  • Data Source
    J-STAGE 
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