Title: Electrified fallout from a wildfire plume Show Chinese title

Title: 带电的野火烟雾沉降

Abstract: Large wildfires are becoming more frequent at temperate latitudes. Often, fires generate massive convective columns that can carry solid particles (ash) into the stratosphere. Like their meteorological counterparts, pyrocumulonimbus (pyroCb) clouds can generate intense lightning storms. Recently, pyrogenic lightning has garnered renewed interest for its capacity to ignite new fires at large distances from the initial fire (in addition to representing a hazard in and of itself). Furthermore, and in analogy with volcanogenic lightning, pyrogenic lightning may offer novel opportunities to monitor and infer the internal dynamics of wildfires remotely. However, the electrification mechanisms underlying wildfire lightning require further clarification. Here, we report on charge measurements conducted during the 2022 Cedar Creek ``megafire.'' We find that a wildfire plume associated with various pyCb events remains mildly electrified at $\sim$80 km from the fire. Our measurements suggest that individual ash particles carry charge densities on the order of 10\textsuperscript{-8} - 10\textsuperscript{-7} C m\textsuperscript{-2}. Owing to this low level of charging, additional electrification mechanisms (perhaps, those associated with the nucleation of ice) appear to be necessary to produce pyrogenic lightning at large distances from the source. Show Chinese abstract

Abstract: 大规模野火在温带纬度变得越来越频繁。 通常，火灾会产生巨大的对流柱，能够将固体颗粒（灰烬）带入平流层。 与气象对等物类似，火积云（pyrocumulonimbus，pyroCb）云可以产生强烈的闪电风暴。 最近，由火灾产生的闪电因其能够在初始火灾远处点燃新火灾的能力而重新引起关注（除了本身是一种危险之外）。 此外，类似于火山闪电，火灾闪电可能为远程监测和推断野火内部动力学提供新的机会。 然而，野火闪电背后的充电机制需要进一步澄清。 在这里，我们报告了在2022年 Cedar Creek“巨灾”期间进行的电荷测量。 我们发现，与各种 pyCb 事件相关的野火烟羽在距离火灾$\sim$80 公里处仍保持轻微带电。 我们的测量表明，单个灰烬颗粒的电荷密度约为 10\textsuperscript{-8}到 10\textsuperscript{-7} C m\textsuperscript{-2}。 由于这种低水平的充电，似乎需要额外的充电机制（可能是与冰核形成相关的机制）才能在远离源的地方产生火灾闪电。