Abstract A suite of aircraft measurements was conducted over the Gulf of Tonkin, located downwind to the east of Mainland Southeast Asia (MSE), between March 23rd and April 6th, 2015. To the best of our knowledge, this campaign of 11 flights (totaling 34.4 h) was the first in-flight measurement over the region. Measurements of sulfur dioxide, nitrogen oxides, ozone, carbon monoxide, black carbon and the particulate scattering coefficient were recorded at approximately 1 500 m (low level) and 3 000 m (high level). Significantly higher measurements of black carbon, carbon monoxide and ozone in the high level on March 23rd and April 5th and 6th were directly related to biomass burning in the MSE and were comparable to severe pollution events at the surface. Similarly, relatively low pollutant concentrations were observed at both altitudes between March 23rd and April 5th. A combined analysis of the measurements with meteorology and satellite data verified that the plumes captured at 3 000 m were attributed to transport in the high altitude originating from biomass burning in northern MSE. Furthermore, each plume captured by the measurements in the high level corresponded to heavy regional air pollution caused by biomass burning in northern MSE. In addition, relatively low levels of the measured pollutants corresponded to relatively light pollution levels in MSE and its adjacent areas. Taken together, these results indicated that aircraft measurements were accurate in characterizing the variation in transport and pollutant levels. During the most active season of biomass burning in MSE, pollutant emissions and their regional impact could vary on an episodic basis. Nonetheless, such concentrated emissions from biomass burning is likely to lead to particularly high atmospheric-loading of pollutants at a regional level and, depending on weather conditions, has the potential of being transported over considerably longer distances. Further investigation of the short-term impacts of such concentrations therefore appears prudent.

中文翻译：

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东京湾上空的飞机测量捕获生物质燃烧的高空运输

摘要 2015 年 3 月 23 日至 4 月 6 日，在位于东南亚大陆 (MSE) 以东下风向的北部湾上空进行了一系列飞机测量。 34.4 小时）是该地区的首次飞行测量。二氧化硫、氮氧化物、臭氧、一氧化碳、黑碳和颗粒散射系数的测量值记录在大约 1 500 m（低水平）和 3 000 m（高水平）。3 月 23 日和 4 月 5 日和 6 日，高浓度黑碳、一氧化碳和臭氧的测量值显着升高，这与 MSE 中的生物质燃烧直接相关，并且与地表的严重污染事件相当。相似地，3 月 23 日至 4 月 5 日期间，在两个海拔高度都观察到相对较低的污染物浓度。对测量结果与气象学和卫星数据的综合分析证实，在 3 000 m 处捕获的羽流归因于 MSE 北部生物质燃烧引起的高海拔运输。此外，高水平测量捕获的每个羽流都对应于 MSE 北部生物质燃烧造成的严重区域空气污染。此外，测量到的污染物水平相对较低，对应于 MSE 及其邻近地区的相对较轻的污染水平。综上所述，这些结果表明飞机测量在表征运输和污染物水平的变化方面是准确的。在 MSE 生物质燃烧最活跃的季节，污染物排放及其对区域的影响可能会因偶发而不同。尽管如此，生物质燃烧产生的这种集中排放很可能会导致区域一级污染物在大气中的负荷特别高，并且根据天气条件，有可能被输送到更长的距离。因此，对此类浓度的短期影响进行进一步调查似乎是谨慎的。