Spatio-temporal variation characteristics of global wildfires and their emissions
Intense regional wildfires are a common occurrence in the context of climate warming and have progressively evolved into one of the major natural disasters in terrestrial ecosystems, posing a serious hazard to the atmosphere and climate change. We investigated the spatial distribution, intensity, em...
| Main Authors: | , , , , |
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| Format: | Text |
| Language: | English |
| Published: |
2023
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| Subjects: | |
| Online Access: | https://doi.org/10.5194/acp-2022-829 https://acp.copernicus.org/preprints/acp-2022-829/ |
| Summary: | Intense regional wildfires are a common occurrence in the context of climate warming and have progressively evolved into one of the major natural disasters in terrestrial ecosystems, posing a serious hazard to the atmosphere and climate change. We investigated the spatial distribution, intensity, emission changes, and meteorological differences of wildfires in different wildfire active and wildfire-prone regions globally based on multi-source satellite remote sensing fire data, emission data, and meteorological data in order to better understand the change trend of wildfire activity at multiple spatial and temporal scales. The findings demonstrate that while the wildfire burned area (BA) has decreased slowly over the last 20 years, the wildfire burned fraction (BF), the fire count (FC), and the fire radiative power (FRP) all exhibit pronounced regional and seasonal variations. The physical characteristics of wildfires, including the BF, FC and FRP, experience greater seasonal variation as latitude increases, with summer and autumn as the reasons with the most frequent wildfires worldwide. This study also shows that the emission declined substantially between 2012 and 2020 in Northern Canada, Alaska, and Northeast China, whereas it notably increased in the Siberia region during the same period, primarily due to a rise in summer emissions. The results based on classification show that the absolute amount of CO 2 produced by wildfires is the largest, and the difference among regions is relatively small. Excluding CO 2 , aerosol emissions (the total of OC, TC, and BC) ranged from 78.6 % to 84.2 %, while the least significant air pollutants (the total of PM 2.5 , SO 2 , and NO x ) ranged from 5.8 % to 11.7 %. The abundance of vegetation predominately affects the intensity change of wildfire development, while the weather conditions can also indirectly influence the incidence of wildfire by altering the growth condition of vegetation. Correspondingly, the increase in temperature in the northern hemisphere's middle and ... |
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