Application of a 3-D Urban Surface-Sensor-Sun Model to Estimate Urban Thermal Anisotropy for a Range of Urban Geometries

The SUM (surface-sensor-sun relations model) proposed by Soux et al. (2001) is able to model how a remote sensor views a simple urban surface. When combined with surface temperature information, it is able to estimate the directional variation (anisotropy) of radiative temperature as seen by a given remote sensor-sun-surface configuration. Results from SUM to date have been constrained by the availability of observed surface temperatures for specific urban geometries. Here we use the canyon energy balance model of Mills (1997) to estimate surface temperatures for a range of simple urban geometries that may then be modeled within SUM. This framework is used to assess the anisotropy for a range of urban geometries and to provide a sensitivity analyses to the anisotropy from measures affecting the temperature of the urban surfaces. This approach provides an intermediate step towards a more fully coupled energy balance model with SUM that will be able to provide temperatures of urban surface facets for specific urban geometries.