气候变化领域集成服务门户(CCPortal): Geographically divergent trends in snow disappearance timing and fire ignitions across boreal North America

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DOI	10.5194/bg-21-109-2024
	Geographically divergent trends in snow disappearance timing and fire ignitions across boreal North America
	Hessilt, Thomas D.; Rogers, Brendan M.; Scholten, Rebecca C.; Potter, Stefano; Janssen, Thomas A. J.; Veraverbeke, Sander
发表日期	2024
ISSN	1726-4170
EISSN	1726-4189
起始页码	21
结束页码	1
卷号	21 期号:1
英文摘要	The snow cover extent across the Northern Hemisphere has diminished, while the number of lightning ignitions and amount of burned area have increased over the last 5 decades with accelerated warming. However, the effects of earlier snow disappearance on fire are largely unknown. Here, we assessed the influence of snow disappearance timing on fire ignitions across 16 ecoregions of boreal North America. We found spatially divergent trends in earlier (later) snow disappearance, which led to an increasing (decreasing) number of ignitions for the northwestern (southeastern) ecoregions between 1980 and 2019. Similar northwest-southeast divergent trends were observed in the changing length of the snow-free season and correspondingly the fire season length. We observed increases (decreases) over northwestern (southeastern) boreal North America which coincided with a continental dipole in air temperature changes between 2001 and 2019. Earlier snow disappearance induced earlier ignitions of between 0.22 and 1.43 d earlier per day of earlier snow disappearance in all ecoregions between 2001 and 2019. Early-season ignitions (defined by the 20 % earliest fire ignitions per year) developed into significantly larger fires in 8 out of 16 ecoregions, being on average 77 % larger across the whole domain. Using a piecewise structural equation model, we found that earlier snow disappearance is a good direct proxy for earlier ignitions but may also result in a cascade of effects from earlier desiccation of fuels and favorable weather conditions that lead to earlier ignitions. This indicates that snow disappearance timing is an important trigger of land-atmosphere dynamics. Future warming and consequent changes in snow disappearance timing may contribute to further increases in western boreal fires, while it remains unclear how the number and timing of fire ignitions in eastern boreal North America may change with climate change.
语种	英语
WOS研究方向	Environmental Sciences & Ecology ; Geology
WOS类目	Ecology ; Geosciences, Multidisciplinary
WOS记录号	WOS:001168864600001
来源期刊	BIOGEOSCIENCES
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/290052
作者单位	Vrije Universiteit Amsterdam
推荐引用方式 GB/T 7714	Hessilt, Thomas D.,Rogers, Brendan M.,Scholten, Rebecca C.,et al. Geographically divergent trends in snow disappearance timing and fire ignitions across boreal North America[J],2024,21(1).
APA	Hessilt, Thomas D.,Rogers, Brendan M.,Scholten, Rebecca C.,Potter, Stefano,Janssen, Thomas A. J.,&Veraverbeke, Sander.(2024).Geographically divergent trends in snow disappearance timing and fire ignitions across boreal North America.BIOGEOSCIENCES,21(1).
MLA	Hessilt, Thomas D.,et al."Geographically divergent trends in snow disappearance timing and fire ignitions across boreal North America".BIOGEOSCIENCES 21.1(2024).