近日，美国普渡大学X. Shen团队研究了对流层生物质燃烧和深对流对平流层气溶胶的扰动。相关论文发表在2025年10月13日出版的《自然—地球科学》杂志上。
平流层通常被认为是稳定的，只有极少的垂直混合。然而，深层对流可以输送对流层以上的低空物质。
研究组通过“夏季平流层动力学与化学”任务的原位单粒子测量发现：在2022年火活动活跃季节，对流层顶上方4公里大气层中，直径0.1-1.5微米的平流层颗粒物有高达90%源自碳质-硫酸盐混合粒子。研究显示约43%的平流层碳质-硫酸盐颗粒来源于生物质燃烧。
这些化学结构复杂、有机物富集的粒子进入平流层后并非保持原状，而是形成了同时包含对流层与平流层组分的混合体系，这表明平流层气溶胶层正在受到扰动。研究组认为，随着气候变暖背景下野火频次与强度的持续增加，以及深层对流活动的加剧，可能会促使更多生物质燃烧产物进入低平流层，从而对臭氧化学过程和辐射强迫产生重要影响。
附：英文原文
Title: Stratospheric aerosol perturbation by tropospheric biomass burning and deep convection
Author: Shen, X., Jacquot, J. L., Li, Y., Sharpe, S. A. L., Dykema, J. A., Schill, G. P., Bowman, K. P., Homeyer, C. R., Fraund, M., Moffet, R. C., Olayemi, T. E., Pittman, J. V., Rivera-Adorno, F. A., Murphy, D. M., Smith, J. B., Laskin, A., Keutsch, F. N., Cziczo, D. J.
Issue&Volume: 2025-10-13
Abstract: The stratosphere is generally considered to be stable, with minimal vertical mixing. However, deep convection can transport low-altitude material above the tropopause. Here we use in situ single-particle measurements from the Dynamics and Chemistry of the Summer Stratosphere mission to show that carbonaceous-sulfate particles from the troposphere account for up to 90% of the stratospheric particles with physical diameter from 0.1 to 1.5μm in a 4-km layer above the tropopause during an active fire season in 2022. We find that ~43% of the stratospheric carbonaceous-sulfate particles originate from biomass burning. These particles, which are chemically complex and organic-rich, do not remain unchanged once injected into the stratosphere, but form mixtures containing both tropospheric and stratospheric components, indicating perturbation of the stratospheric aerosol layer. We suggest that the increasing frequency and intensity of wildfires combined with increasing deep convection as the climate warms may enhance the delivery of biomass burning products to the lower stratosphere, with implications for ozone chemistry and radiative forcing.
DOI: 10.1038/s41561-025-01821-1
Source: https://www.nature.com/articles/s41561-025-01821-1