Jun 27, 2012
Satellite-based assessment of climate controls on US burned area
by
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Biogeosciences Discussions
- Conducts the first national assessment of climate controls on US fire activity using two satellite-based estimates of monthly burned area (BA), the Global Fire Emissions Database (GFED, 1997–2010) and Monitoring Trends in Burn Severity (MTBS, 1984–2009) BA products
- Analyzes the relationships between monthly BA and potential evaporation (PE) derived from reanalysis climate data at 0.5° resolution for each US National Climate Assessment (NCA) region
- Finds that US fire activity increased over the past 25 yr, with statistically significant increases in MTBS BA for entire US and the Southeast and Southwest NCA regions
- Finds that monthly PE was strongly correlated with US fire activity, yet the climate driver of PE varied regionally
- Finds that fire season temperature and shortwave 15 radiation were the primary controls on PE and fire activity in the Alaska, while water deficit (precipitation – PE) was strongly correlated with fire activity in the Plains regions and Northwest US
- Finds that BA and precipitation anomalies were negatively correlated in all regions, although fuel-limited ecosystems in the Southern Plains and Southwest exhibited positive correlations with longer lead times (6–12 months)
- Finds that fire season PE increased from the 1980s–2000s, enhancing climate-driven fire risk in the southern and western US where PE-BA correlations were strongest
- Finds that spatial and temporal patterns of increasing fire season PE and BA during the 1990s–2000s highlight the potential sensitivity of US fire activity to climate change in coming decades
- Finds, however, that climate- fire relationships at the national scale are complex, based on the diversity of fire types, ecosystems, and ignition sources within each NCA region
- Concludes that changes in the seasonality or magnitude of climate anomalies are therefore unlikely to result in uniform changes in US fire activity