Field observations of radiation and heat balances on a grass spot and an artificial ground in an Urban area

In order to evaluate the effects of grass spots on mitigating urban heatisland phenomena, radiation and heat balances were observed on a grass spot and an artificial ground in summer season. In the daytime, the air and the surface temperatures on the grass spot were much the same as those on the artificial ground, but the downward conductive heat flux on the grass surface was much lower, due to the latent-heat consumption. The surface temperature on the grass spot dropped rapidly in the evening, and the air on the cold grass surface was cooled through the nighttime.