Characterising the influence of atmospheric mixing state on Urban Heat Island Intensity using Radon-222

• Published in: Atmospheric environment (1994) 2016-12, Vol.147, p.355-368
• Main Authors: Chambers, Scott D., Podstawczyńska, Agnieszka, Williams, Alastair G., Pawlak, Włodzimierz
• Format: Article
• Language: English
• Subjects: 222Rn; Atmospheric stability; Nocturnal boundary layer; UHI; Urban climate
• ISSN: 1352-2310; 1873-2844
• DOI: 10.1016/j.atmosenv.2016.10.026

Characterisation of the effects of varying atmospheric mixing states (stability) in urban climate studies has historically been hampered by problems associated with the complexity of the urban environment, representativity of measurement techniques, and the logistical and financial burdens of maintaining multiple long-term comprehensive measurement sites. These shortcomings, together with a lack of a consistent measurement approach, have limited our ability to understand the physical processes contributing to the urban heat island effect. In this study, we analyse 4 years of continuous hourly near-surface meteorological and atmospheric radon data from an urban–rural site pair in central Poland. A recently-developed radon-based stability classification technique, previously developed for urban pollution characterisation, is employed to characterise the Urban Heat Island Intensity (UHII) and other climatic factors over the full diurnal cycle by season and atmospheric mixing state. By characterising the UHII over a range of atmospheric mixing states in a statistically robust way, this technique provides an effective tool for assessing the efficacy of mitigation measures for urban climate effects in a consistent way over timescales of years to decades. The consistency of approach, ease of application, and unprecedented clarity of findings, provide a strong argument for atmospheric radon observations to be included as part of the ‘standard measurement suite’ for urban climate monitoring networks for non-coastal cities. •New application of a radon-based atmospheric stability classification technique.•Novel approach for quantifying urban climate influences for all weather conditions.•Convenient, economical tool for assessing efficacy of UHII mitigation strategies.•Consistent way to compare urban climate effects across different regions and settings.