Analysis of source regions for smoke events in Singapore for the 2009 El Nino burning season
Analysis of source regions for smoke events in Singapore for the 2009 El Nino burning season
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DOI：
10.1016/j.atmosenv.2013.04.047
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发表时间：
2013-10-01
影响因子：
5
通讯作者：
Balasubramanian, Rajasekhar
中科院分区：
文献类型：
--
作者：
Atwood, Samuel A.;Reid, Jeffrey S.;Balasubramanian, Rajasekhar
作为7东南亚研究（7 SEAS）计划的一部分，新加坡国立大学（NUS）开发了一个太阳辐射和化学采样点（“超级采样点”），以监测区域空气质量。2009年8月至10月期间，该地点的第一个密集作业期恰逢中度厄尔尼诺事件和热带燃烧加剧，特别是在泥炭地。我们使用这一时期的数据来分析运输的海洋大陆（MC）的NUS supersite的生物质燃烧排放。概述了新加坡的气溶胶环境，随后对四个气溶胶事件进行了更详细的讨论。2009年的燃烧季节与以前的分析中所描述的相似，这表明火灾活动始于苏门答腊MC的西半部，并及时向东传播。同样，首先发生的是农业燃烧，一般随后是森林砍伐和泥炭地火灾。一些生物质燃烧排放物进入自由对流层，在那里它们通过盛行风模式进行区域性传输。我们的分析表明，在850百帕（类似于1500米）的季节性风转移的传输模式从源区到新加坡的西南部，到东南部地区的过程中的夏季季风，模式，使新加坡受到影响的峰值燃烧区在MC。相比之下，地面的风更典型地来自南部和东南部，表明该地区垂直风切变的普遍性。由于可变的源区影响新加坡上空不同层次的大气，气溶胶质量浓度的现场地面观测结果并不总是与从气柱光学深度推断存在增强的气溶胶浓度一致。我们的研究结果证实了气溶胶来源和运输的MC的复杂性，以及生物质燃烧排放在影响柱气溶胶光学厚度和总颗粒物质量浓度在表面发挥的关键作用。NUS supersite的海平面高度意味着边界层以上传输的非本地污染物不能可靠地采样和表征，但本地排放和向下混合的综合影响，非本地污染物在新加坡一致测量。(C)2013爱思唯尔有限公司出版
As part of the 7 SouthEast Asian Studies (7SEAS) program, a solar radiation and chemistry sampling site ("supersite") was developed at the National University of Singapore (NUS) to monitor regional air quality. The first intensive operations period for this site occurred between August and October 2009, a period that coincided with a moderate El Nino event and enhanced tropical burning, particularly in peatlands. We use data from this period to analyze the transport of biomass burning emissions in the Maritime Continent (MC) to the NUS supersite. An overview of the aerosol environment is provided for Singapore, followed by more detailed discussion of four aerosol events. The 2009 burning season was similar to those described in previous analyses, which showed that fire activity begins in the western half of the MC in Sumatra and propagates eastward in time. Similarly, agricultural burning occurs first, generally followed by deforestation and peatland fires. Some of the biomass burning emissions make their way into the free troposphere, where they are transported regionally by the prevailing wind patterns. Our analyses show that the seasonal winds at 850 hPa (similar to 1500 m) shift transport patterns from source regions to the southwest of Singapore, to regions to the southeast over the course of the summer monsoon, patterns that allow Singapore to be impacted by peak burning regions in the MC. In contrast, winds at the surface are more typically from the south and southeast, demonstrating the prevalence of vertical wind shear over the region. As a result of the variable source regions influencing different levels of the atmosphere over Singapore, in-situ surface observations of aerosol mass concentrations are not always consistent with inferences of the presence of enhanced aerosol concentration from column optical depth. Our findings confirm the complexity of aerosol sources and transport over the MC, and the key role that biomass burning emissions play in influencing column aerosol optical depth and total particulate mass concentrations at the surface. The sea-level altitude of the NUS supersite means that non-local pollution transported above the boundary layer cannot be reliably sampled and characterized, but the combined effects of local emissions and downward-mixed, non-local pollutants in Singapore were consistently measured. (C) 2013 Published by Elsevier Ltd.