Drought triggers and sustains overnight fires in North America
Overnight fires are emerging in North America with previously unknown drivers and implications. This notable phenomenon challenges the traditional understanding of the ‘active day, quiet night’ model of the diurnal fire cycle 1 – 3 and current fire management practices 4 , 5 . Here we demonstrate th...
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| Vydané v: | Nature (London) Ročník 627; číslo 8003; s. 321 - 327 |
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| Hlavní autori: | , , , |
| Médium: | Journal Article |
| Jazyk: | English |
| Vydavateľské údaje: |
London
Nature Publishing Group UK
14.03.2024
Nature Publishing Group |
| Predmet: | |
| ISSN: | 0028-0836, 1476-4687, 1476-4687 |
| On-line prístup: | Získať plný text |
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| Shrnutí: | Overnight fires are emerging in North America with previously unknown drivers and implications. This notable phenomenon challenges the traditional understanding of the ‘active day, quiet night’ model of the diurnal fire cycle
1
–
3
and current fire management practices
4
,
5
. Here we demonstrate that drought conditions promote overnight burning, which is a key mechanism fostering large active fires. We examined the hourly diurnal cycle of 23,557 fires and identified 1,095 overnight burning events (OBEs, each defined as a night when a fire burned through the night) in North America during 2017–2020 using geostationary satellite data and terrestrial fire records. A total of 99% of OBEs were associated with large fires (>1,000 ha) and at least one OBE was identified in 20% of these large fires. OBEs were early onset after ignition and OBE frequency was positively correlated with fire size. Although warming is weakening the climatological barrier to night-time fires
6
, we found that the main driver of recent OBEs in large fires was the accumulated fuel dryness and availability (that is, drought conditions), which tended to lead to consecutive OBEs in a single wildfire for several days and even weeks. Critically, we show that daytime drought indicators can predict whether an OBE will occur the following night, which could facilitate early detection and management of night-time fires. We also observed increases in fire weather conditions conducive to OBEs over recent decades, suggesting an accelerated disruption of the diurnal fire cycle.
By examining the hourly diurnal cycle of 23,557 fires in North America during 2017–2020, 1,095 overnight burning events were identified, mostly associated with extreme fires and driven by long-term drought conditions. |
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| Bibliografia: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 14 content type line 23 |
| ISSN: | 0028-0836 1476-4687 1476-4687 |
| DOI: | 10.1038/s41586-024-07028-5 |