On the vertical distribution of smoke in the Amazonian atmosphere during the dry season
On the vertical distribution of smoke in the Amazonian atmosphere during the dry season
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DOI：
10.5194/acp-16-2155-2016
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发表时间：
2015-11
影响因子：
6.3
通讯作者：
F. Marenco;B. Johnson;J. Langridge;J. Mulcahy;A. Benedetti;S. Rémy;L. Jones;K. Szpek;J. Haywood;K. Longo;P. Artaxo
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文献类型：
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作者：
F. Marenco;B. Johnson;J. Langridge;J. Mulcahy;A. Benedetti;S. Rémy;L. Jones;K. Szpek;J. Haywood;K. Longo;P. Artaxo
抽象的。对BAE-146研究飞机在生物质燃烧季节(2012年9月)在巴西上空进行的六次飞行中对烟雾气溶胶的激光雷达观测进行了分析。观测到了大的气溶胶光学厚度，通常范围为0.4-0.9，典型的气溶胶消光系数为10 0-4 0 0 mm−1。这些数据突出了亚马逊雾霾的持续性和广泛性，这种雾霾具有一致的垂直结构，在长达14天的时间里(∼2 2 0 0公里)被观测到。在地表附近发现了气溶胶；但较大的气溶胶负荷通常出现在延伸1-1.5至4-6公里的高空。将测量结果与气象局统一模型(MetUM)和ECMWF-MACC模型的模型预测进行了比较。MetUM大体上复制了用激光雷达观测到的亚马孙雾霾的垂直结构。ECMWF-MACC模式也能够再现烟羽的一般特征，尽管对AOD略有高估。这些模型并不总是捕捉到局部特征，例如(I)来自个别火灾的烟羽，以及(Ii)云附近的气溶胶。在这两种情况下，都遇到了1000-1500 mm−1数量级的峰值消光系数和1-1.8AOD，但这些特征要么被低估，要么没有在模型预测中被捕捉到。从全球火灾同化系统(GFAS)得出的该区域的烟雾喷射高度与气溶胶层的一般高度是一致的。
Abstract. Lidar observations of smoke aerosols have been analysed from six flights of the Facility for Airborne Atmospheric Measurements BAe-146 research aircraft over Brazil during the biomass burning season (September 2012). A large aerosol optical depth (AOD) was observed, typically ranging 0.4–0.9, along with a typical aerosol extinction coefficient of 100–400 Mm−1. The data highlight the persistent and widespread nature of the Amazonian haze, which had a consistent vertical structure, observed over a large distance ( ∼ 2200 km) during a period of 14 days. Aerosols were found near the surface; but the larger aerosol load was typically found in elevated layers that extended from 1–1.5 to 4–6 km. The measurements have been compared to model predictions with the Met Office Unified Model (MetUM) and the ECMWF-MACC model. The MetUM generally reproduced the vertical structure of the Amazonian haze observed with the lidar. The ECMWF-MACC model was also able to reproduce the general features of smoke plumes albeit with a small overestimation of the AOD. The models did not always capture localised features such as (i) smoke plumes originating from individual fires, and (ii) aerosols in the vicinity of clouds. In both these circumstances, peak extinction coefficients of the order of 1000–1500 Mm−1 and AODs as large as 1–1.8 were encountered, but these features were either underestimated or not captured in the model predictions. Smoke injection heights derived from the Global Fire Assimilation System (GFAS) for the region are compatible with the general height of the aerosol layers.