EGU21-10702
https://doi.org/10.5194/egusphere-egu21-10702
EGU General Assembly 2021
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Fire regime impacts on post-fire diurnal land surface temperature change over North American boreal forest

Jie Zhao1,2, Chao Yue1,2, Philippe Ciais3, Xin Hou1, and Qi Tian1
Jie Zhao et al.
  • 1College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, China
  • 2State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling 712100, China
  • 3Laboratoire des Sciences du Climat et de l’Environnement, CEA-CNRS-UVSQ, F-91191 Gif sur Yvette, France

Wildfire is the most prevalent natural disturbance in the North American boreal (BNA) forest and can cause post-fire land surface temperature change (ΔLSTfire) through biophysical processes. Fire regimes, such as fire severity, fire intensity and percentage of burned area (PBA), might affect ΔLSTfire through their impacts on post-fire vegetation damage. However, the difference of the influence of different fire regimes on the ΔLSTfire has not been quantified in previous studies, despite ongoing and projected changes in fire regimes in BNA in association with climate change. Here we employed satellite observations and a space-and-time approach to investigate diurnal ΔLSTfire one year after fire across BNA. We further examined potential impacts of three fire regimes (i.e., fire intensity, fire severity and PBA) and latitude on ΔLSTfire by simple linear regression analysis and multiple linear regression analysis in a stepwise manner. Our results demonstrated pronounced asymmetry in diurnal ΔLSTfire, characterized by daytime warming in contrast to nighttime cooling over most BNA. Such diurnal ΔLSTfire also exhibits a clear latitudinal pattern, with stronger daytime warming and nighttime cooling one year after fire in lower latitudes, whereas in high latitudes fire effects are almost neutral. Among the fire regimes, fire severity accounted for the most (43.65%) of the variation of daytime ΔLSTfire, followed by PBA (11.6%) and fire intensity (8.5%). The latitude is an important factor affecting the influence of fire regimes on daytime ΔLSTfire. The sensitivity of fire intensity and PBA impact on daytime ΔLSTfire decreases with latitude. But only fire severity had a significant effect on nighttime ΔLSTfire among three fire regimes. Our results highlight important fire regime impacts on daytime ΔLSTfire, which might play a critical role in catalyzing future boreal climate change through positive feedbacks between fire regime and post-fire surface warming.

How to cite: Zhao, J., Yue, C., Ciais, P., Hou, X., and Tian, Q.: Fire regime impacts on post-fire diurnal land surface temperature change over North American boreal forest, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-10702, https://doi.org/10.5194/egusphere-egu21-10702, 2021.

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