Wang Wen-Jia, Zhang Qi-Xing, Zhang Yong-Ming
State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei 230026, China.
Ying Yong Sheng Tai Xue Bao. 2022 Feb;33(2):537-543. doi: 10.13287/j.1001-9332.202202.017.
Smoke injection height is a key driving factor for plume transport, which determines the lifetime of smoke aerosol in the atmosphere, transport path and diffusion along with the wind, and impacts on atmospheric environment. In this study, raw data obtained from the latest multi-angle imaging spectroradiometer (MISR) plume height project was extracted and analzyed. The variation of smoke injection heights of wildfire in China was investigated with statistical analysis methods. The effects of fire characteristics (combustion biomass type and fire radiative power) on the smoke injection height were explored. Meanwhile, the influence of smoke injection heights on the atmospheric environment was discussed based on the proportion of higher injection height plumes and the value of smoke aerosol optical depth (AOD). The results showed that smoke injection heights from wildfire ranged from 345 to 7719 m, with 57.1% of which ranging from 500 to 1000 m. Except for an abnormally high value of smoke injection height from a large grassland fire, the rest of smoke injection heights were lower than 3000 m. The biomass type for combustion was an important factor affecting smoke injection heights. The injection heights of the plume caused by forest fire were the highest and had the greatest variability. Smoke injection heights increased with the fire radiation power, but with obvious dispersion (=0.19). By setting a simple threshold, the proportion of higher injection plumes which might cause long-distance transportation of air pollutants in China was 10.5%. Combined with the analysis of smoke AOD, it was found that the average smoke injection height from cropland burning was the lowest, but their smoke caused the highest regional air pollution. In contrast, although forest fires could produce the highest smoke injection height, their smoke had a lower average value of AOD, which indicated a relatively weak impact of forest fires on regional air quality.
烟雾注入高度是烟羽传输的关键驱动因素，它决定了烟雾气溶胶在大气中的寿命、传输路径以及随风扩散情况，还会对大气环境产生影响。在本研究中，提取并分析了从最新的多角度成像光谱辐射计（MISR）烟羽高度项目中获得的原始数据。采用统计分析方法研究了中国野火烟雾注入高度的变化情况。探讨了火灾特征（燃烧生物质类型和火灾辐射功率）对烟雾注入高度的影响。同时，基于较高注入高度烟羽的比例和烟雾气溶胶光学厚度（AOD）值，讨论了烟雾注入高度对大气环境的影响。结果表明，野火的烟雾注入高度范围为345至7719米，其中57.1%的高度范围在500至1000米之间。除一场大型草原火灾的烟雾注入高度出现异常高值外，其余烟雾注入高度均低于3000米。燃烧的生物质类型是影响烟雾注入高度的重要因素。森林火灾产生的烟羽注入高度最高且变化最大。烟雾注入高度随火灾辐射功率增加，但离散度明显（=0.19）。通过设定一个简单阈值，在中国可能导致空气污染物长距离传输的较高注入烟羽的比例为10.5%。结合烟雾AOD分析发现，农田燃烧的平均烟雾注入高度最低，但其烟雾造成的区域空气污染最高。相比之下，尽管森林火灾能产生最高的烟雾注入高度，但其烟雾的AOD平均值较低，这表明森林火灾对区域空气质量的影响相对较弱。
