Konovalov Igor B, Golovushkin Nikolai A, Beekmann Matthias
A.V. Gaponov-Grekhov Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia.
A.V. Gaponov-Grekhov Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia.
Sci Total Environ. 2024 Nov 15;951:175518. doi: 10.1016/j.scitotenv.2024.175518. Epub 2024 Aug 15.
Powerful wildfires occurring in Siberia each summer emit large amounts of smoke aerosol that, according to studies of the environmental impacts of biomass burning (BB) aerosol in different regions of the world, can affect precipitation and other weather parameters and induce feedback on fires. However, the knowledge of smoke-weather interactions and fire-weather feedback in Siberia is presently limited. To advance this knowledge, we performed coupled-meteorology-chemistry simulations of aerosols and weather in a Siberian region covering taiga and tundra using the CHIMERE chemistry-transport model and the WRF meteorological model. We addressed a monthly period of July 2016 and considered several modeling scenarios in which aerosol-radiation interaction (ARI) and aerosol-cloud interaction (ACI) were taken into account jointly or separately. The simulation results were combined with emission and precipitation data retrieved from satellite observations. The joint analysis of the simulated precipitation fields and satellite-observation-based data revealed that in the taiga, the inhibiting effect of Siberian smoke on precipitation induced a significant positive feedback on BB aerosol emissions that, according to our estimates, enhanced by 27 (±7) % respective to a hypothetical situation in which smoke-weather interactions were absent. At the same time, an increase of precipitation over active fire spots due to ACI and ARI in tundra led to the formation of a negative feedback loop between fire emissions and BB smoke, resulting in a reduction of BB aerosol emissions there by 14 (±6) %. Hence, this study revealed evidence for significant feedback of smoke-induced precipitation changes on fire emissions in Siberia. Given the global importance of Siberia as a major carbon sink, this feedback needs to be studied further and accurately taken into account in projections of climate change both on regional and global scales.
每年夏天在西伯利亚发生的强烈野火会释放大量烟雾气溶胶。根据对世界不同地区生物质燃烧（BB）气溶胶环境影响的研究，这些气溶胶会影响降水和其他天气参数，并引发对火灾的反馈。然而，目前关于西伯利亚烟雾与天气相互作用以及火灾与天气反馈的知识有限。为了增进这方面的了解，我们使用CHIMERE化学传输模型和WRF气象模型，对一个覆盖泰加林和苔原的西伯利亚地区的气溶胶和天气进行了气象 - 化学耦合模拟。我们研究了2016年7月的月度情况，并考虑了几种建模情景，其中分别或联合考虑了气溶胶 - 辐射相互作用（ARI）和气溶胶 - 云相互作用（ACI）。模拟结果与从卫星观测中获取的排放和降水数据相结合。对模拟降水场和基于卫星观测的数据进行联合分析后发现，在泰加林地区，西伯利亚烟雾对降水的抑制作用引发了对BB气溶胶排放的显著正反馈。据我们估计，与不存在烟雾 - 天气相互作用的假设情况相比，这种正反馈使排放增强了27（±7）%。与此同时，由于苔原地区的ACI和ARI，活跃火点上空的降水增加，导致火灾排放与BB烟雾之间形成了负反馈回路，使得该地区的BB气溶胶排放减少了14（±6）%。因此，这项研究揭示了西伯利亚烟雾引起的降水变化对火灾排放有显著反馈的证据。鉴于西伯利亚作为主要碳汇在全球的重要性，这种反馈需要进一步研究，并在区域和全球尺度的气候变化预测中准确考虑。
