Achievement

Kyle Maurer, a first year BART fellow examined roughness length of the forest at the University of Michigan Biological Station, using flux data from the Station's Ameriflux site. Surface roughness length is used in atmospheric modeling to vertically scale the wind profile and to calculate the drag force that the surface applies on the atmosphere. In forests, roughness length is largely affected by the leaf area index (LAI), the mean tree height, the vertical distribution of leaf density and the horizontal heterogeneity of canopy structure. Kyle and his colleagues described the phenology of roughness length and how it relates to the seasonal dynamics of LAI. They found that there is a non-linear change in roughness length during leaf transitional stages, which cannot be described with LAI alone, due to change in canopy structure during the leaf-on and leaf-off processes. This research was presented at the AGU Fall 2009 Meeting.