Institute of Low Temperature Science, Hokkaido University , Sapporo 060-0819, Japan.
Environ Sci Technol. 2014;48(15):8491-7. doi: 10.1021/es500794d. Epub 2014 Jul 16.
We investigated organic molecular compositions of summertime aerosols collected at the summit of Mt. Fuji (3776 m a.s.l.) in July-August 2009. More than 120 organic species were identified using GC/MS. Concentrations of both primary and secondary organic aerosol (SOA) tracers in whole-day samples were 4-20 times higher than those in nighttime samples, suggesting that valley breeze is an efficient mechanism to uplift the aerosols and precursors from the ground surface to mountaintop in daytime. Using a tracer-based method, we estimated the concentrations of secondary organic carbon (SOC) derived from isoprene, α/β-pinene, and β-caryophyllene to be 2.2-51.2 ngC m(-3) in nighttime and 227-1120 ngC m(-3) during whole-day. These biogenic SOCs correspond to 0.80-31.9% and 26.8-57.4% of aerosol organic carbon in nighttime and whole-day samples, respectively. This study demonstrates that biogenic SOA, which is controlled by the valley breeze, is a significant fraction of free tropospheric aerosols over Mt. Fuji in summer.
我们研究了 2009 年 7 月至 8 月在富士山山顶（海拔 3776 米）采集的夏季气溶胶的有机分子组成。使用 GC/MS 鉴定了超过 120 种有机物质。全日样品中一次和二次有机气溶胶（SOA）示踪剂的浓度比夜间样品高 4-20 倍，表明山谷风是白天将气溶胶和前体从地面抬升到山顶的有效机制。使用基于示踪剂的方法，我们估计了异戊二烯、α/β-蒎烯和β-石竹烯衍生的二次有机碳（SOC）的浓度在夜间为 2.2-51.2ngC m(-3)，全日为 227-1120ngC m(-3)。这些生物源 SOC 分别占夜间和全日样品气溶胶有机碳的 0.80-31.9%和 26.8-57.4%。这项研究表明，受山谷风控制的生物源 SOA 是夏季富士山自由对流层气溶胶的重要组成部分。
