Investigation of Tropospheric Ozone Production in Association with Biomass Burning in Southeast Asia

对流层臭氧对全球大气环境具有重要意义，因为它会损害人类健康和包括农作物在内的植被。它还影响气候，因为它是一种重要的温室气体。然而，臭氧的分布、预算以及因此对环境的影响尚未得到充分了解。本文讨论了东南亚地区生物质燃烧对对流层臭氧产生的影响。本研究包括三个部分：(I)在BIBLE飞机观测活动期间观测到的臭氧变化和印度尼西亚地区生物质燃烧的影响；（II）在TRACE-P飞机观测活动期间观测到的臭氧增加层数和印度支那地区生物质燃烧的影响；（III）在密集臭氧观测中观测到的印度支那上空臭氧变化和印度支那地区生物质燃烧的影响。在BIBLE期间，热带太平洋上空O_3及其前体气体（OPG）的混合比相当低。在对流层上层，OPG在印尼东部和西部顺风逐渐增加。虽然O_3在印度尼西亚上空没有增加，但在经过印度尼西亚上空的气团中，在印度洋和澳大利亚北部观测到O_3增加了50%。这些结果表明，臭氧是在印度尼西亚上空受排放和对流影响的气团中产生的。运输过程中O_3的平均产率估计约为2ppbv/天，与光化学模型计算结果相当。这些结果表明，即使在生物质燃烧不活跃的情况下，印度尼西亚上空与生物质燃烧和闪电相关的对流也会影响印度尼西亚上空的OPG量，并导致印度洋和澳大利亚北部O_3增加10-15 ppbv（约50%）。在TRACE-P期间，副热带纬度约20N的西太平洋和中太平洋上空约4 km高度经常观测到臭氧和OPG的增加。轨迹分析和OPG与示踪剂之间的比对分析表明，臭氧和OPG的增加归因于印度支那地区的生物质燃烧。2003年3月至6月在泰国Sri Samrong （17N, 99E）进行了一次密集的臭氧观测。整个对流层观测到的臭氧混合比一般超过60 ppbv，有时超过90 ppbv。在观测期内，泰国上空约4 km高度存在一个稳定的逆温层，表明生物质燃烧和工业活动释放的臭氧前体向上输送到该逆温层。然而，臭氧混合比在该层上下没有显著变化。气象分析结合气溶胶特征分析表明，东南亚地区的生物质燃烧不仅是主要的臭氧源，而且南亚污染物和中纬度的输送也对高臭氧浓度有贡献，甚至在逆温层以下。少

Tropospheric ozone is significant for global atmospheric environment because it can damage human health and vegetation including agricultural crops. It also affects climate because is one of significant greenhouse gases. However, the ozone distribution, its budget, and therefore, its influence on the environment have not been fully understood. In this study, the influence of the biomass burning in Southeast Asia on the production of the tropospheric ozone is discussed. This study consists of three parts : (I)ozone variation observed during the BIBLE aircraft observation campaigns and influence of biomass burning in the Indonesian region, (II)ozone increased layers observed during the TRACE-P aircraft observation campaign and influence of biomass burning in the Indochina region, and (III)ozone variation over Indochina observed by an intensive ozonezonde observation and influence of biomass burning in the Indochina region.During BIBLE, mixing ratios of O_3 and its precursor gases (OPG) w … More ere quite low over the tropical Pacific Ocean. In the upper troposphere, OPG gradually increased downwind in eastern and western Indonesia. While O_3 did not increased over Indonesia, it increased by 50 % in the air masses which passed over Indonesia and were observed in Indian Ocean and northern Australia. These results indicate that ozone was produced in the air masses affected by emissions and convection over Indonesia. Average O_3 production rate during transport is estimated to be about 2ppbv/day, being comparable with the photochemical model calculation. These results demonstrate that the convection over Indonesia in association with biomass burning and lightning influenced OPG amount over Indonesia, even when biomass burning was inactive, and that it caused 10-15 ppbv (about 50 %) increase of O_3 over Indian Ocean and northern Australia.During TRACE-P, increase of ozone and OPG was often observed at the altitude around 4 km over western and central Pacific in subtropical latitude at about 20N. Trajectory analyses and collation analyses between OPG and tracers indicate that this increase of ozone and OPG were attributed to the biomass burning in the Indochina region.An intensive ozonesonde observation was carried out at Sri Samrong (17N, 99E), Thailand, between March and June, 2003. Observed ozone mixing ratios generally exceeded 60 ppbv and sometimes exceeded 90 ppbv throughout the troposphere. There was a stable inversion layer at an altitude around 4 km over Thailand during the observation period, indicating that ozone precursors emitted from biomass burning and industrial activities were upwardly transported up to this layer. However, ozone mixing ratios did not show significant variation above and below this layer. Meteorological analyses combined with analyses of aerosol characteristics indicated that biomass burning in Southeast Asia was not only a dominant ozone source, but also the pollutant from South Asia and the transport from the middle latitude contributed to the high ozone concentrations, even below the inversion layer. Less