jaue2016025: Investigation of Summer Radiation Environments in the Urban Canyon: A Proposal of Traverse Observation Method for Downward Shortwave

Abstract

The radiative environments in the urban canyon are formed under the influence of the surrounding walls. In this paper, authors assumed the downward radiation observed at the place where there are little buildings andtrees in the surrounding area as the background condition of downward shortwave radiation. In order to evaluate urban radiative environments, authors normalized observed values in streets with the downward shortwave radiation in the background. Authors designated the normalized downward shortwave radiation as downward shortwave radiant quantities rate to the background. This index can evaluate with removing the fluctuations of the amount of radiation in the background. In addition, authors tried to estimate downward shortwave radiation in street by using this index. The radiation environment is affected by surrounding environment, land cover and street direction. Authors evaluated overall radiation environment with using the MRT. Next, authors also evaluated the correlation among the surrounding environment and 4 components ofradiant quantities (longwave and shortwave radiating in two directions). The downward longwave radiation and the sky view factor are negatively correlated. Second, authors calculated road surface reflectance bydividing the upward shortwave radiation by the downward shortwave radiation. So, authors evaluated the correlation among the upward longwave radiation and road surface temperature.