Atmospheric moisture's influence on fire behavior: Surface moisture and plume dynamics

Abstract

Nine measures of atmospheric surface moisture are tested for statistical relationships with fire size and number of fires using data from the Great Lakes region of the United States. The measures include relative humidity, water vapor mixing ratio, mixing ratio deficit, vapor pressure, vapor pressure deficit, dew point temperature, dew point depression, wet bulb temperature and wet bulb depression. Two moisture-related measures of the vertical stability of the atmosphere (Convective available potential energy and a modified version of the same quantity) are also tested for the same fire data. Results suggest that measures that indicate the difference between equilibrium moisture content of the atmosphere and actual moisture content correlate more strongly with fire number in a region than do measures of actual moisture content. None of the moisture measures, including stability measures, appear to correlate with individual fire size.