Estimating spatial patterns of air temperature at building resolving spatial resolution in Seoul, Korea
The thermal environment in urban areas is substantially influenced by local surface properties and their modification through human activities. The effects of urban climate on human health are one of the motivations for the development of various urban climate analysis tools. Climate Analysis Seoul (CAS) is a tool that incorporates a meso scale atmospheric model and conceptual geographic information system (GIS) based models to provide gridded air temperature deviations based on high resolution land cover information. The CAS output was evaluated using air temperatures observed at 18 automatic weather stations (AWS) located in the detail region (DR) Eunpyeong. Correlation analyses were performed to reveal the influence of different land cover characteristics and CAS output variables on measured air temperature deviations. Based on the results of the correlation analyses in the study region (SR) Seoul, a regression model (total air temperature distribution, TD' was developed. It predicts spatially distributed air temperatures based on morphological parameters and an observed reference temperature. Using the TD' model, maps of daily maximum air temperatures were produced for the entire area of Seoul with a horizontal resolution of 25 m, and of 5 m for the DR, the latter allows to assess the impacts of different building and vegetation structures on air temperature by resolving buildings. The TD' model was evaluated using measurements at eight AWS. The TD' model slightly overestimated daily maximum air temperatures in 2007 and 2011, but performed better for 2011, mainly because land cover data represent the final state of the urban development. The TD' model appears to be a suitable tool for estimating air temperature distributions at building resolving resolutions. It can be used to assess changes in the thermal environment and heat related hazards through urban development plans already ahead of their realization.