AbstractThis research contrasts the environmental conditions, meteorological drivers, and air quality impacts of human‐ and lightning‐ignited wildfires in the southeastern and western United States, the two continental U.S. regions with the most wildfire burn area. We use the Fire Program Analysis Wildfire Occurrence Data (FPA FOD) to determine wildfire abundance and ignition sources between 1992 and 2015. We investigate specific ecoregions within these two U.S. regions and find that in the majority of ecoregions, annual lightning‐ and human‐ignited wildfire burn area have similar relationships with key meteorological parameters. We investigate the fuel moisture values where wildfires occur segregated by ignition type and show that within a given ecoregion, the differences in median fuel moisture between ignition types are generally smaller than the differences between ecoregions. Our results suggest that annual wildfire burn area for human‐ and lightning‐ignited wildfires within a given ecoregion are modulated by environmental conditions, and climate change may similarly impact wildfires of both ignition types. Finally, we estimate fine particulate matter emissions for Fire Program Analysis Wildfire Occurrence Data wildfires using the Fire INventory from NCAR model framework. We show that emissions of fine particulate matter from human‐ignited wildfires is significant and of a similar total magnitude between the west and southeastern United States. Additionally, the west and southeast have a similar number of wildfires associated with National Weather Service air quality smoke forecasts.

中文翻译：

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美国东南部和西部野火的环境条件、点火类型和空气质量影响

摘要这项研究对比了美国东南部和西部这两个美国大陆野火烧毁面积最大的地区，人为和闪电引发的野火的环境条件、气象驱动因素和空气质量影响。我们使用火灾程序分析野火发生数据 (FPA FOD) 来确定 1992 年至 2015 年间的野火丰度和点火源。我们调查了这两个美国地区的特定生态区，发现在大多数生态区中，每年由闪电和人为引发的火灾野火燃烧面积与关键气象参数具有类似的关系。我们研究了按点火类型划分发生野火的燃料湿度值，结果表明，在给定的生态区内，不同点火类型之间燃料湿度中值的差异通常小于生态区域之间的差异。我们的研究结果表明，特定生态区内人为和闪电引发的野火的年度野火燃烧面积受到环境条件的调节，气候变化可能同样影响这两种点火类型的野火。最后，我们使用 NCAR 模型框架的火灾清单估算了火灾程序分析野火发生数据野火的细颗粒物排放量。我们发现，人类点燃的野火所排放的细颗粒物数量很大，并且美国西部和东南部之间的总量级相似。此外，西部和东南部也有类似数量的与国家气象局空气质量烟雾预报相关的野火。