Towards a continuous climatological assessment of urban surface heat islands

This paper presents a method of analysis for deriving temporally continuous urban surface temperature and heat island assessments from hemispherical measurements of upwelling thermal radiation. This method was developed to overcome geometric and temporal biases inherent in traditional thermal remote sensing of urban surface climates. Hemispherical surface temperatures are derived from atmospherically corrected and geometrically weighted upwelling thermal irradiances. Results show significant variations in the magnitude of atmospheric influence on the at-sensor surface temperature signal based on time of day, and ambient and synoptic conditions. In addition, we present a temporally continuous comparison of surface and canopy layer urban heat island magnitudes over a range of representative summertime atmospheric conditions.