Variability of wildland fire emissions across the contiguous United States

This study analyzes spatial and temporal variability of emissions from wildland fires across the contiguous US. The emissions are estimates based on a recently constructed dataset of historical fire records collected by multiple US governmental agencies. Both wildfire and prescribed fires have the highest emissions over the Pacific coastal states. Prescribed fire emissions are also found to be high over the southeastern coastal area. Temporal variations of wildfire emissions in various regions are characterized by a number of strong emissions over the past two decades, which are closely related to precipitation anomalies. Prescribed fire emissions, on the other hand, show an increasing tendency in recent years. An analysis of the emissions specifically for the three National Emissions Inventory (NEI) base years of 1996, 1999, and 2002 suggests that the average of these years would represent fairly typical wildfire emissions for all regions except the Southwest and Pacific Southwest. Prescribed fire emissions during the NEI base years, on the other hand, were much higher than the historical average for all regions except the Southeast.