Abstract
Energy budgets at the air/ground interface were measured and analyzed for various pavement materials on summer days. The surface temperature, heat storage, and its subsequent emission to the atmosphere were significantly greater for asphalt than for concrete or bare soil. At the maximum, asphalt pavement emitted as additional 150W/m2 in infrared radiation and 50W/m2 in sensible transport compared to a bare soil surface.
Analysis based on a parallel layer model indicated that most of the infrared radiation from the ground was absorbed within 200m of the lower surface layer, affecting the air temperature near the ground. With a large temperature gap across the ground surface, in addition to a high surface temperature, the rate of infrared absorption over asphalt was greater by 60W/m2 than the rate over soil or concrete, a figure comparable to the absorption by sensible transport.
