HR: 09:45h
AN: U51A-08    [Abstracts]
TI: Antecedent Precipitation Trumps Drought in Causing Southeast Arizona Wildfires
AU: * Comrie, A C
EM: comrie@arizona.edu
AF: University of Arizona, Dept of Geography 409 Harvill Bldg, Tucson, AZ 85721-0076 United States
AU: Crimmins, M A
EM: crimmins@email.arizona.edu
AF: University of Arizona, Dept of Geography 409 Harvill Bldg, Tucson, AZ 85721-0076 United States
AB: Long-term antecedent climate conditions are often overlooked as important drivers of wildfire variability. Fuel moisture levels and fine-fuel productivity are controlled by variability in precipitation and temperature at long timescales (months to years) prior to wildfire events. This study examines relationships between wildfire statistics (total area burned and total number of fires) aggregated for southeastern Arizona and antecedent climate conditions relative to 29 fire seasons (April-May-June) between 1973 and 2001. High and low elevation fires were examined separately to determine the influence of climate variability on dominant fuel types (low elevation grasslands with fine fuels vs. high elevation forests with heavy fuels). Positive correlations between lagged precipitation and total area burned highlight the importance of climate in regulating fine fuel production for both high and low elevation fires. Surprisingly, no significant negative correlations between precipitation and seasonal wildfire statistics were found at any seasonal lag. Drought conditions were not associated with higher area burned or a greater number of fires. Larger low elevation fires were actually associated with wet antecedent conditions until just prior to the fire season. Larger high elevation fires were associated with wet conditions during seasons up to three years prior to the fire season.
DE: 3309 Climatology (1620)
DE: 1812 Drought
DE: 1833 Hydroclimatology
DE: 1610 Atmosphere (0315, 0325)
DE: 0345 Pollution--urban and regional (0305)
SC: Union [U]
MN: 2004 AGU Fall Meeting