Spatiotemporal variation characteristics of global fires and their emissions

• Published in: Atmospheric Chemistry and Physics
• Main Authors: Fan, Hao, Yang, Xingchuan, Zhao, Chuanfeng, Yang, Yikun, Shen, Zhenyao
• Format: Text
• Language: English
• Published: 2023
• Subjects: Canada; Alaska; Siberia
• Online Access: https://doi.org/10.5194/acp-23-7781-2023; https://acp.copernicus.org/articles/23/7781/2023/

Intense regional fires 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 between fires in different fire-active and fire-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 fire activity at multiple spatial and temporal scales. The findings demonstrate that while the burned area (BA) has decreased slowly over the last 20 years, the burned fraction (BF), the fire count (FC), and the fire radiative power (FRP) all exhibit pronounced regional and seasonal variations. The physical characteristics of fires, including the BF, FC, and FRP, experience greater seasonal variation as latitude increases, with summer and autumn being the seasons with the most frequent fire occurrence worldwide. This study also shows that the emissions declined substantially between 2012 and 2020 in northern Canada, Alaska, and northeastern 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 difference in CO 2 produced by fires among regions is relatively small. Excluding CO 2 , aerosol emissions (the total of organic carbon (OC), total carbon (TC), black carbon (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 in fire development, while the weather conditions can also indirectly influence the incidence of fire by altering the growth condition of vegetation. Correspondingly, the increase in temperature in the Northern Hemisphere's middle- and high-latitude forest regions ...