Back of the envelope calculation: Yuma International (discussed above) has 540,000m^2 of runways. Assume a depth of 0.1m of cooling, that is 54,000m^3. The den

Back of the envelope calculation: Yuma International (discussed above) has 540,000m^2 of runways. Assume a depth of 0.1m of cooling, that is 54,000m^3. The density of asphalt is 2322kg/m^3, so we have 310^9kg. The specific heat of asphalt is 900 J/kgK, so that'd be 310^12J to get rid of 1 K degree. The specific heat of water is 4184J/kgC. If I assume the water goes from nearly freezing to nearly boiling and have my algebra right, that's about 6,000,000kg of water or about 6000m^3 of water, all to lower the asphalt by 1 degree. That's about 2.5 standard bulk units of water (Olympic swimming pools). By comparison, 2.5cm of rain on the same runway area is about 13,500m^3 (?) of water. I think it's doable. Anybody got some spare garden hoses? :-)