Spatio-temporal variation in dry season determines the Amazonian fire calendar

Author(s)

Carvalho, Nathalia S. ^{[1, 2]} ; Anderson, Liana O. ^{[3, 2]} ; Nunes, Cassio A. ^[4] ; Pessoa, Ana C. M. ^{[1, 2]} ; Silva Junior, Celso H. L. ^{[1, 2, 5]} ; Reis, Joao B. C. ^{[3, 2]} ; Shimabukuro, Yosio E. ^{[1, 2]} ; Berenguer, Erika ^{[6, 7]} ; Barlow, Jos ^{[7, 4]} ; Aragao, Luiz E. O. C. ^{[8, 1, 2]}

Affiliation

^[1] Natl Inst Space Res, Earth Observat & Geoinformat Div, Sao Jose Dos Campos, SP - Brazil

^[2] Trop Ecosyst & Environm Sci Lab TREES, Sao Jose Dos Campos, SP - Brazil

^[3] Natl Ctr Monitoring & Early Warning Nat Disasters, Sao Jose Dos Campos, SP - Brazil

^[4] Univ Fed Lavras, Dept Ecol & Conservacao, Lavras - Brazil

^[5] Univ Estadual Maranhao UEMA, Dept Engn Agr, Sao Luis, Maranhao - Brazil

^[6] Univ Oxford, Sch Geog & Environm, Environm Change Inst, Oxford - England

^[7] Univ Lancaster, Lancaster Environm Ctr, Lancaster - England

^[8] Univ Exeter, Exeter, Devon - England

• Document type: Journal article
• Source: ENVIRONMENTAL RESEARCH LETTERS; v. 16, n. 12 DEC 2021.
• Web of Science Citations: 0

Abstract

Fire is one of the main anthropogenic drivers that threatens the Amazon. Despite the clear link between rainfall and fire, the spatial and temporal relationship between these variables is still poorly understood in the Amazon. Here, we stratified the Amazon basin according to the dry season onset/end and investigated its relationship with the spatio-temporal variation of fire. We used monthly time series of active fires from 2003 to 2019 to characterize the fire dynamics throughout the year and to identify the fire peak months. More than 50% (32 246) of the annual mean active fires occurred in the peak month. In 52% of the cells, the peaks occurred between August-September and in 48% between October-March, showing well-defined seasonal patterns related to spatio-temporal variation of the dry season. Fire peaks occurred in the last two months of the dry season in 67% of the cells and in 20% in the first month of the rainy season. The shorter the dry season, the more concentrated was the occurrence of active fires in the peak month, with a predominance above 70% in cells with a dry season between one and three months. We defined a Critical Fire Period by identifying the consecutive months that concentrated at least 80% of active fires in the year. This period included two to three months between January and March in the northwest, and in the far north it lasted up to seven months, ending in March-April. In the south, it varied between two and three months, starting in August. In the northeast, it was three to four months, between August and December. By quantifying the role of the dry season in driving fire seasonality across the Amazon basin, we provide recommendations to monitor fire dynamics that can support decision makers in management policies and measures to avoid environmentally or socially harmful fires. (AU)

• FAPESP's process: 16/02018-2 - Interannual variation of Amazon Basin greenhouse gas balances and their controls in a warming and increasingly variable climate – Carbam: the Amazon carbon balance long-term study
• Grantee: Luciana Vanni Gatti
• Support Opportunities: Research Program on Global Climate Change - Thematic Grants
• FAPESP's process: 20/08916-8 - Prediction of forest degradation as a subsidy for mitigating actions to preventing fires and wildfires
• Grantee: Liana Oighenstein Anderson
• Support Opportunities: Regular Research Grants