Comparison of surface radiation and turbulent heat fluxes in Olympic Forest Park and on a building roof in Beijing, China

An effective combination of buildings and parks, as the two core elements of cities, plays an important role in regulating urban climate and ecosystem services. We conducted a comprehensive observation campaign at an Olympic Forest Park site and a surrounding building roof site from 2011 to 2012, with half-hour time step details, including observations of meteorological conditions, radiation and surface heat fluxes. We attempted to find out the effects of changes in the surface radiation and energy balance due to the underlying surface structure and used material by statistical analysis. As expected, besides regular heat fluxes exchange, we also observed larger (by 20.35 W/m(2)) sensible heat fluxes in the park site than in the building roof during winter. We found the horizontal advection disrupts the local energy balance and modifies the near surface air temperature. Specifically, horizontal advection bringing in external energy would reduce the difference of local near surface temperature between the park and the building roof and weaken the cooling effect of the park. The relationship between urban land cover and its structure and urban surface heat fluxes can be analyzed and discussed, which can provide some practical evidence for future urban construction planning and residents' health.