Hydrological drivers of hydrogen cyanide wildfire emissions from Indonesian peat fires during the 2015, 2019, and 2023 El Niño events

IF 5.7 1区地球科学 Q1 ENVIRONMENTAL SCIENCES

Atmospheric Chemistry and Physics Pub Date : 2026-09-14 DOI:10.5194/acp-26-12925-2026

Antonio G. Bruno,David P. Moore,Jeremy J. Harrison,Ailish Graham,Martyn P. Chipperfield,Corinne Vigouroux

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Abstract

Indonesian peatlands store vast amounts of carbon that are highly vulnerable to fire during El Niño-driven droughts. When ignited, peat releases large quantities of greenhouse gases and other species with significant environmental impacts, including hydrogen cyanide (HCN), a sensitive tracer of smouldering combustion. In this work, we use new satellite retrievals from the Infrared Atmospheric Sounding Interferometer (IASI) spectra using the University of Leicester IASI retrieval scheme (ULIRS), that we validate against ground-based Fourier transform infrared (FTIR) measurements at Reunion Maido, TOMCAT atmospheric model simulations, hydrological information, and fire activity observations to evaluate the factors driving trace gas emissions during the 2015, 2019, and 2023 El Niño events. The 2015 El Niño produced large burdens of HCN and carbon monoxide (CO), unprecedented in the satellite observational era and driven by exceptionally low soil moisture, depressed groundwater levels, and deep burn depths. In contrast, the 2019 and 2023 events exhibited markedly weaker emissions despite similar Oceanic Niño Index (ONI) anomalies, reflecting more favourable hydrological conditions. Comparisons of the satellite trace gas observations with simulations of the TOMCAT model show that burned-area-based inventories such as the Global Fire Emissions Database (GFED) version 4 substantially overestimate emissions from peat fires in 2015, while a new peat-specific database, FINNpeatSM (Fire Inventory from NCAR (FINNv1.5) New peat with Soil Moisture), better represents fire season timing and burn depth by incorporating soil moisture constraints. From satellite-derived HCN : CO enhancement ratios, we provide new emission factors for HCN that offer benchmarks for new emission inventories. Our results show that peat fire intensity and emissions are driven not only by El Niño strength but also by local hydrological conditions such as soil water content and precipitation. Integrating hydrological indicators with satellite observations of atmospheric composition is therefore critical for improving fire emission inventories.

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2015年、2019年和2023年El Niño事件期间印度尼西亚泥炭火灾氰化氢野火排放的水文驱动因素

印尼泥炭地储存着大量的碳，在厄尔尼诺Niño-driven干旱期间极易受到火灾的影响。当被点燃时，泥炭会释放出大量的温室气体和其他对环境有重大影响的物质，包括氰化氢（HCN），一种敏感的阴燃示踪剂。在这项工作中，我们使用莱斯特大学红外大气探测干涉仪（IASI）检索方案（ulrs）从红外大气探测干涉仪（IASI）光谱中获得的新卫星检索数据，我们对留尼旺Maido的地基傅里叶变换红外（FTIR）测量数据、TOMCAT大气模型模拟、水文信息和火灾活动观测进行验证，以评估2015年、2019年和2023年El Niño事件期间驱动微量气体排放的因素。2015年厄尔尼诺现象Niño产生了大量的HCN和一氧化碳（CO），这在卫星观测时代是前所未有的，并受到土壤湿度异常低、地下水水位下降和深烧伤深度的驱动。相比之下，2019年和2023年事件的排放量明显较弱，尽管海洋Niño指数（ONI）异常相似，反映出更有利的水文条件。卫星微量气体观测结果与TOMCAT模型模拟结果的对比表明，基于燃烧区域的清单（如全球火灾排放数据库（GFED）第4版）大大高估了2015年泥炭火灾的排放量，而新的泥炭特定数据库FINNpeatSM（来自NCAR （FINNv1.5）含土壤湿度的新泥炭火灾清单）通过纳入土壤湿度限制，更好地代表了火灾季节时间和燃烧深度。根据卫星衍生的HCN: CO增强比，我们为HCN提供了新的排放因子，为新的排放清单提供了基准。研究结果表明，泥炭火灾强度和排放不仅受El Niño强度的驱动，还受土壤含水量和降水等当地水文条件的影响。因此，将水文指标与大气成分的卫星观测相结合对于改进火灾排放清单至关重要。

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来源期刊

Atmospheric Chemistry and Physics 地学-气象与大气科学

CiteScore

10.70

自引率

20.60%

发文量

702

审稿时长

6 months

期刊介绍： Atmospheric Chemistry and Physics (ACP) is a not-for-profit international scientific journal dedicated to the publication and public discussion of high-quality studies investigating the Earth''s atmosphere and the underlying chemical and physical processes. It covers the altitude range from the land and ocean surface up to the turbopause, including the troposphere, stratosphere, and mesosphere. The main subject areas comprise atmospheric modelling, field measurements, remote sensing, and laboratory studies of gases, aerosols, clouds and precipitation, isotopes, radiation, dynamics, biosphere interactions, and hydrosphere interactions. The journal scope is focused on studies with general implications for atmospheric science rather than investigations that are primarily of local or technical interest.