Global Climatology of Vegetation Aerodynamic Roughness for Momentum Using MODIS and ICESat Data Products

Global climatologies of vegetation aerodynamic roughness for momentum and zero plane displacement height are presented using ICESat and time series MODIS data products. The roughness climatologies are generated by combining published MODIS leaf-area index products and ICESat canopy heights with a previously developed representation of the roughness sublayer. The primary dataset consists of the global mean annual cycle of roughness at 500-m spatial resolution with a nominal 8-day time step. A secondary dataset includes spatial and temporal averages for a range of MODIS land cover types. Results indicate that the new satellite-based roughnesses compare favorably to field data and typical look-up tables often employed in land surface modeling for broad cover types, while also providing a measure of variability that one can expect from naturally varying canopy structure as defined by height and leaf area index.