Contribution of urban park to thermal comfort and CO2 mitigation in a hot-humid environment

Urban parks provide a wide range of services for healthcare and social welfare. In particular, they function as a key link connected to urban ecosystems, mitigating various environmental problems such as urban heat island effect and greenhouse emission. It is, therefore, urgent to improve our understanding of the role of the urban park in regulating their surrounding environment. We observed surface turbulent fluxes at an artificially constructed Seoul Forest Park (SFP) in Seoul, for two years from June 2013 to May 2015. The objectives of the study are to 1) quantify water, energy and CO₂ exchanges from urban park into the atmosphere and 2) quantify the effect of the urban park on microclimate through comparison before and after the park construction and comparison with urbanized surrounding areas and 3) identify abiotic and biotic factors controlling the temperature reduction and CO₂ offset.

Our analysis shows that SFP in summer daytime has cooler surface air temperature up to -0.6 ℃ with a Bowen ratio of 0.15 than surrounding commercial-residential zone in Seoul. SFP also acts as local sinks, and its carbon uptake gives economic benefits in terms of a carbon tax and reduction of heatwaves. Our findings indicate the important role of urban parks in mitigating urban heat island intensity and CO₂ emission from urban areas and in providing eco-social benefits with us.