MEASUREMENTS OF SPATIAL DISTRIBUTION OF AEROSOLS AND THEIR CHARACTERISTICS BY GROUND-BASED AND AERIAL OBSERVATIONS

在本研究课题中，我们通过实验分析了大气中气溶胶及其前体的动力学，阐明了气溶胶的空间分布，阐明了气溶胶在长距离输送过程中的化学转化过程。为此，分析最大排放源地区即中国的影响是必不可少的。然而，到目前为止，对中国的观测实验被认为是不可能的。在这项研究中，我们可以在中国开展气溶胶和大气污染物的航空观测实验。1.2002年12月至1月，在中国上空进行了三次航空观测。2003年8月-9月2003年和2004年5月至6月。在一个大排放源附近，NOx与臭氧呈负相关，与SO2呈高度正相关。根据这些数据估算了NOx/SO2比值，并通过与排放清单数据的对比，证实了近期NOx增加和/或SO2减少的现象。硫酸盐和硝酸盐与氨氮具有良好的相关性。中国上空气溶胶中的酸性物种与氨有很好的中和作用。从有机气溶胶的分析可以看出，中国存在高浓度的邻苯二甲酸和邻苯二甲酸盐。2.对冲绳地区的气溶胶及其前体进行了连续的地面观测。分析了中国输送的硫酸盐和硝酸盐以及南亚和东南亚输送的碳质气溶胶的输送过程和化学转化过程。明确了水溶性有机气溶胶的季节变化是一个显著的结果。

In this research subject, we carried out experiments to analyze the dynamics of aerosols and their precursors in the atmosphere as well as to elucidate the spatial distribution of aerosols and to clarify the chemical transformation processes on the way of long-range transports. For this purpose it is indispensable to analyze the effect of the biggest emission source region, i.e., China. However, the observation experiments over China were thought impossible so far. In this study we could carry out aerial observation experiments of aerosols and air pollutants in China.1.Three times of aerial observations over China were performed in Dec. 2002-Jan. 2003, Aug.-Sept. 2003, and May-June 2004. In the vicinity of a large emission source NOx showed anti-correlation with ozone and high positive correlation with SO_2. NOx/SO_2 ratio was estimated based on those data and the recent phenomena of NOx increase and/or SO_2 decrease were confirmed by comparison with emission inventory data. Sulfates and nitrates showed good correlation with ammonium. Acidic species in aerosols over China were well neutralized with ammonia. From the analysis of organic aerosols, it became clear that there are high concentration of phthalic acid and phthalates in China.2.Continuous ground-based measurements of aerosols and their precursors were carried out in Okinawa. Analyses of transport process and chemical transformation process were made for not only sulfates and nitrates from China but also carbonaceous aerosols transported from South and/or Southeast Asia. It is a remarkable result that the seasonal variation of water soluble organic aerosols was clarified.