日本夏期夜間の高湿度下における水蒸気凝結を考慮したエアロゾルのヒートアイランド効果への寄与評価

概要

論文の詳細を見る
Heat island is a serious problem these days. In this study, the temperature variation during the summer nights induced by aerosol is evaluated using a numerical simulation taking into account vapor condensation. Since the particle size of aerosol is smaller than the wavelength of the earth radiation, it was thought that the temperature was not influenced by aerosol during the night. However it is also suspected that the night temperature is high due to the increase in aerosol diameter by condensation. The numerical simulation assumed that the aerosol consists of ammonium sulfate and that the aerosols vertical concentration profile has the same pattern as that of the observed extinction coefficient of aerosol by Lidar. The simulation showed the temperature rise depends on the aerosol particle density, i.e., the rise in temperature at the aerosol particle density of 105/cm3 is 0.4 degree higher than that at 103/cm3. Since the aerosol particle density in an urban area is generally higher than that in a rural area, it is expected that the descent in the night temperature in the urban area is smaller compared to that in the rural. The heat island analysis carried out for Tokyo as an example revealed that the contribution of aerosol to the heat island is almost the same as that of anthropogenic heat.
日本エアロゾル学会の論文