Assessment of Urbanization Impact on the Continental U.S. Surgace Climate

Simple Biospheric Model (SiB2)-based retrospective runs were performed to examine urban heat island (UHI) dynamic from hourly to seasonal time scale over the Continental U.S. at 5kmx5km horizontal resolution with focus on major urban centers. The impervious surface area (ISA) data from the continental scale National Land Cover Database (NLCD) were combined to MODIS data to produce a multi-dimensional land cover map a 5x5 km with sub-grid fractions information. We produce realistic initial conditions and integrate the model for 3 year period using hourly NLDAS2 atmospheric forcing fields. Interactions between urban and different vegetation classes will be assessed for better understanding the vegetation control on UHI hourly and seasonal dynamics. UHI analysis over several urban centers will be presented.