2010年度富士山測候所 研究報告書(速報 その4)

氏 名: 河村公隆(Kimitaka KAWAMURA)
所 属: 北海道大学 低温科学研究所(Institute of Low Temperature Science, Hokkaido Univ.)   

関宰(Osamu SEKI)1)、藤原真太郎(Shintaro FUJIWARA)1),2)

1)北海道大学 低温科学研究所(Institute of Low Temperature Science, Hokkaido Univ.)

2)北海道大学大学院 環境科学院(Graduate School of Environmental Science, Hokkaido Univ.)

研究テーマ: 富士山頂における有機エアロゾルの組成と起源に関する研究

A study on chemical composition and origin of organic aerosols collected at the summit of Mt. Fuji





①ハイボリュームエアサンプラー(HV): 全粒径かつ詳細な化合物の分析に必要な大容量のエアロゾル粒子の捕集を目的とする。

②ミドルボリュームインパクター(MVI): 粒径別の粒子を捕集し、エアロゾルの生成過程や存在状態に関する考察を行うことを目的とする。

③ローボリュームインパクター(LV): 気体として多くが存在している有機酸(ギ酸や酢酸など)の捕集を目的とした小型のサンプラー。フィルターにはガスとエアロゾル粒子の両方を捕集する。






  Aerosols, suspended particles in the atmosphere, are thought to affect climate and weather condition via scattering solar radiation and acting as a cloud condensation nuclei (CCN), which can be a nuclei to form clouds. Among them, water-soluble organic aerosols, including low molecular weight dicarboxylic acids, are thought to have a large effect on a climate. Water-soluble organic aerosols are composed of not only primary emitted materials to the air, but also chemical degradation products of organic precursor compounds. Our laboratory has done many campaigns to reveal chemical compositions and distributions of organic aerosols at many locations.

  This study aim to reveal molecular distributions, origins and transport pathway of organic aerosols over East-Asia and North-East Pacific region by collecting filter samples at the summit of Mt,Fuji following the results of the 2009 campaign.

  We had set three samplers to collect aerosol samples for each objectives described as below.

1. High-Volume air sampler (HV): for Total Suspended Particles (TSP), which will provide enough amounts of compounds needed for detailed chemical analysis.

2. Middle-Volume Impactor (MVI): for size segregated aerosols which will provide information about origin and size distributions of the aerosols in the ambient air.

3. Low-Volume impactor (LV): for organic acids such as formic and acetic acids, most of which exist in a gas phase in the air. The quartz filters that were impregnated with KOH were used to collect gaseous organic acids whereas particulate organic acids were collected on neutral quartz filters.

  Sampling campaign had conducted from July.8th to August 25th 2010 at the outside of the 3rd building at Mt.Fuji weather observatory. 11 HV filters, 10 LV filters and 7 sets of MVI filters were collected in this summer.

  Dicarboxylic acids will be measured by using GC/FID and GC/MS after dibutyl esterification of target compounds. And other organic compounds which was emitted from biomass burning and secondary products of biomass emissions will be also measured. We will consider about effects of these compounds to the free-tropospheric environment.

  By analyzing samples we collected last year, we could identify chemical compositions and size distributions of various organic compounds over Mt.Fuji, and the results also suggested that many organic compounds are transported from the planetary boundary layer to the summit.

  We expect that this year’s sample will bring us more insights about free-tropospheric organic aerosols.