New Mexico Geological Society Annual Spring Meeting — Abstracts

The purpose of this study is to assess the hypothesis that atmospheric aerosol from late spring forest fires depresses precipitation in the subsequent monsoon season in the Southwest. To assess this hypothesis I examined the covariability of observed interannual variability of June forest fires and atmospheric aerosols. I obtained fire data including acres burned, dates, and locations of major fires and total number of fires in New Mexico and Arizona, and satellite-derived estimate of aerosol concentrations for the period of 2005-2012. Using these data I calculated correlations on maps, create and analyzed 3D graphs, calculated the linear correlation between forest fires and the aerosol thickness. Interannual correlation between forest fires in New Mexico and aerosol thicknesses in New Mexico is 0.67, provides support for the hypothesis. In this short period of record, however, this correlation is mostly due to a single year, 2011, when aerosols increased from a high increase in forest fires. Removing this highly anomalous year from the data set reduced the correlation between forest fires and aerosol thicknesses in remaining years to 0.12. Therefore, this study was not definitive on whether or not aerosols produced by late spring forest fires generally depress precipitation in the successive monsoon season in the  Southwest. With only one big variation in the aerosols and forest fires in 2011 out of the 8 years it is hard to see if there is a true regression.