Post-fire trajectories of MODIS land surface properties and their impact on modeled near-surface climate

Forest fires significantly affect the near-surface climatology by causing step-function changes to surface physical properties such as albedo, aerodynamic roughness, and transpiration capacity. We analyzed observations from two AmeriFlux sites near Flagstaff, Arizona - one located in a ponderosa pine forest and the other in a ponderosa pine forest completely burned by wildfire in 1996. Results show that the forest fire effect is strongest in winter daytime net radiation and sensible heat flux with moderate effects to summer daytime ground heat flux and summer nighttime sensible heat flux. The Moderate Resolution Imaging Spectroradiometer (MODIS) burned area product and the Monitoring Trends in Burn Severity (MTBS) dataset are two independent satellite observations of fire location. A spatial comparison of the fire products is made over forested regions in the western United States and Canada for fires occurring between 2001 and 2011. For regions where the products overlap, an analysis is presented to demonstrate the immediate changes in MODIS surface properties (albedo, LAI, FPAR, GPP, NDVI, emissivity) in the post-fire environment along with the near-term (10-year) trajectory of these surface properties, both as a function of burn severity. These surface property trajectories are then incorporated into the Noah-MP land surface model to determine the fire impact on subsequent surface energy and hydrologic cycles.