Mapping the urban thermal pattern of the Salt Lake Valley using advanced thermal land applications sensor airborne data (Utah)

An environmental consequence of urbanization is the urban heat island effect (a situation where urban areas are warmer than surrounding rural areas), which results from the replacement of natural landscapes with impervious surfaces such as concrete and asphalt. The heat retention from impervious surfaces causes a disruption of the surface energy balance, and can exacerbate existing air pollution conditions. In order to better understand the urban microclimate, a greater understanding of the urban thermal pattern, including the thermal properties of individual land covers, is needed. This study utilizes ATLAS (Advanced Thermal Land Applications Sensor) thermal data, a high spatial resolution (10-m) airborne-sensor dataset appropriate for an environment containing a concentration of diverse land covers, in combination with Landsat TM data to examine the overall thermal pattern of the Salt Lake Valley at two levels: (1) the community level and (2) the valley-wide level. The thermal properties of individual land covers are identified, and then used to identify thermal properties of various land uses at both levels. The UTP (Urban Thermal Pattern) of the Salt Lake Valley is then compared to remotely-sensed data at the climate modeling scale, namely 1.1-km ground resolution Landsat TM data.; Results show that a heat island is evident at both the community and the valley-wide level where there is a dominance of impervious surfaces. ATLAS data perform well in community-level studies in terms of land cover and thermal exchanges, but other more coarse-resolution data sets are more appropriate for large-area thermal studies. Remote sensing data, with a variety of spatial and temporal resolutions available, provide an excellent opportunity to examine the holistic nature of the urban microclimate.