Impacts of beetle-kill and wildland fire on regional water and energy cycles in western North America [INVITED]

This project, funded by the NOAA Climate Prediction Program for the Americas (CPPA), seeks to explore the impacts of western forests affected by bark beetle and fire on regional water and energy cycles and their associated intraseasonal to interannual climate variability. To analyze the recovery of physical and physiological parameters important for land surface modeling in forested regions following bark beetle outbreak and wildland fire, we use remote-sensing observations (e.g., 500-m Moderate Resolution Imaging Spectroradiometer, MODIS, and Monitoring Trends in Burn Severity, MTBS). One goal is to develop MODIS-based products to detect tree mortality caused by bark beetle epidemics. These analyses will be used for improving the representation of these forest disturbances in the Noah land surface model (LSM). The modified Noah LSM is used in the context of high-resolution land data assimilation system (HRLDAS) to perform a ten-year (2000-2010) 1-km (covering the area of 30-55oN and 101-120oW) reanalysis of land surface conditions (surface sensible heat flux, evaporation, runoff, soil moisture) by integrating a number of atmospheric observations and fire and bark-beetle outbreak data. The model results will be evaluated against flux-tower observations obtained from affected forest sites (e.g., Flagstaff burned site, Arizona; beetle-infested sites at GLEES and Chimney Park, Wyoming). By contrasting this reanalysis to the one conducted using undisturbed forest data, we can isolate impacts of affected forests on surface exchange of heat and water vapor, snow accumulation, and runoff. Lastly, we will conduct regional climate simulations with the modified WRF/Noah coupled model for selected years to investigate the impacts of the improved realism in representing the modified forest structures on intra-seasonal to interannual precipitation prediction. An analysis of observation data and HRLDAS simulation results will be presented. We will also discuss results from an intensive field campaign using Mobile GPS Advanced Upper-Air Sounding System (MGAUS) to assess evolution of atmospheric boundary layer at a natural and at a burned-forest site in Colorado, in the context of the NCAR Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H2O, Organics & Nitrogen (BEACHON) project.