Faculty of Geomatics, Lanzhou Jiaotong University, Lanzhou 730070, China; Gansu Provincial Engineering Laboratory for National Geographic State Monitoring, Lanzhou 730070, China.
Department of Geography/Geology, University of Nebraska Omaha, Omaha, NE 68182, USA.
Sci Total Environ. 2022 Jun 20;826:154103. doi: 10.1016/j.scitotenv.2022.154103. Epub 2022 Feb 24.
The wildfires of August and September 2020 in the western part of the United States were characterized by an unparalleled duration and wide geographical coverage. A particular consequence of massive wildfires includes serious health effects due to short and long-term exposure to poor air quality. Using a variety of data sources including aerosol optical depth (AOD) and ultraviolet aerosol index (UVAI), obtained with the Moderate-Resolution Imaging Spectroradiometer (MODIS), Multi-Angle Implementation of Atmospheric Correction (MAIAC) and Tropospheric Monitoring Instrument (TROPOMI), combined with meteorological information from the European Center for Medium-Range Weather Forecasts (ECMWF) and other supporting data, the impact of wildfires on air quality is examined in the three western US states, California, Oregon, and Washington, and areas to the east. The results show that smoke aerosols not only led to a significant deterioration in air quality in these states but also affected all other states, Canada, and surrounding ocean areas. The wildfires increased the average daily surface concentration of PM posing significant health risks, especially for vulnerable populations. Large amounts of black carbon (BC) aerosols were emitted into the atmosphere. AOD and UVAI exceeded 1 and 2 over most of the country. In parts of the three western states, those values reached 3.7 and 6.6, respectively. Moreover, a reanalysis based on MERRA-2 (Modern-Era Retrospective Analysis for Research and Applications, version 2) showed that the maximum values of BC surface mass concentration during the wildfires were about 370 μg/m. These various indicators provide a better understanding of the extent of environmental and atmospheric degradation associated with these forest fires.
2020 年 8 月和 9 月美国西部的野火具有前所未有的持续时间和广泛的地理覆盖范围。大规模野火的一个特殊后果是由于短期和长期暴露在空气质量差的环境中而导致严重的健康影响。利用多种数据源，包括气溶胶光学深度 (AOD) 和紫外线气溶胶指数 (UVAI)，这些数据是通过中分辨率成像光谱仪 (MODIS)、多角度大气校正实施 (MAIAC) 和对流层监测仪器 (TROPOMI) 获得的，结合欧洲中期天气预报中心 (ECMWF) 的气象信息和其他支持数据，研究了美国西部三个州——加利福尼亚州、俄勒冈州和华盛顿州以及东部地区野火对空气质量的影响。结果表明，烟雾气溶胶不仅导致这些州的空气质量显著恶化，还影响了所有其他州、加拿大和周边海洋地区。野火使 PM 的日均地面浓度增加，对健康构成重大威胁，尤其是对弱势群体。大量黑碳 (BC) 气溶胶被排放到大气中。AOD 和 UVAI 在该国大部分地区超过 1 和 2。在三个西部州的部分地区，这些值分别达到 3.7 和 6.6。此外，基于 MERRA-2（现代回顾分析用于研究和应用，版本 2）的再分析表明，野火期间 BC 地表质量浓度的最大值约为 370μg/m。这些各种指标提供了对与这些森林火灾相关的环境和大气退化程度的更好理解。
