Feedbacks between climate warming, land surface aridity, and wildfire-derived aerosols represent a large source of uncertainty in future climate predictions. Here, long-term observations of aerosol optical depth, surface level aerosol loading, fire-area burned, and hydrologic simulations are used to show that regional-scale increases in aridity and resulting wildfires have significantly increased summertime aerosol loading in remote high elevation regions of the Intermountain West of the United States. Surface summertime organic aerosol loading and total aerosol optical depth were both strongly correlated (p < 0.05) with aridity and fire area burned at high elevation sites across major western US mountain ranges. These results demonstrate that surface-level organic aerosol loading is dominated by summertime wildfires at many high elevation sites. This analysis provides new constraints for climate projections on the influence of drought and resulting wildfires on aerosol loading. These empirical observations will help better constrain projected increases in organic aerosol loading with increased fire activity under climate change.
University of Utah, Department of Atmospheric Science, Salt Lake City, UT, USA; Desert Research Institute, Division of Atmospheric Science, Reno, NV, USA; Storm Peak Laboratory, Desert Research Institute, Steamboat Springs, CO, USA; University of Colorado, Geography Department and Institute of Arctic and Alpine Research, Boulder, CO, USA; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA; Colorado State University, Cooperative Institute for Research in the Atmosphere, Fort Collins, CO, USA; Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA; Department of Civil, Environmental, and Architectural Engineering, University of Colorado, Boulder, CO, USA; Storm Peak Laboratory, Desert Research Institute, Steamboat Springs, CO, USA; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA; University of Utah, Department of Atmospheric Science, Salt Lake City, UT, USA; Storm Peak Laboratory, Desert Research Institute, Steamboat Springs, CO, USA; Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA; NOAA Earth System Research Laboratory, Boulder, CO, USA; University of Utah, Department of Atmospheric Science, Salt Lake City, UT, USA; Desert Research Institute, Division of Atmospheric Science, Reno, NV, USA; Cooperative Institute for Climate and Satellites, North Carolina State University, Asheville, NC, and National Centers for Environmental Information, Asheville, NC, USA
Recommended Citation:
A Gannet Hallar,Noah P Molotch,Jenny L Hand,et al. Impacts of increasing aridity and wildfires on aerosol loading in the intermountain Western US[J]. Environmental Research Letters,2017-01-01,12(1)