A new convective velocity scale for studying diurnal urban heat island circulation

Yifan Fan, Yuguo Li, Xiaoxue Wang, Franco Catalano

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12 Citations (Scopus)


Urban heat island circulation establishes an urban dome under stable stratification and no background wind conditions. Small-scale water models have been a very useful tool in the exploration of the mechanisms by which urban domes and their associated wind flows are formed. Data are available from a number of water-tank heat island models. Data from field measurements, computational fluid dynamics, and small-scale water-tank experiments are compared in this paper. The small-scale water-tank experiments were found to produce relatively low radial velocities, such as the radial horizontal velocity. Different relevant velocity scales developed in the literature were reviewed. The influence of the Prandtl number on convective flows was analyzed. The analysis resulted in a new convective velocity scale that is a function of the Prandtl number, and the new scale was found to work well. This new development is expected to render small-scale models more useful in urban wind studies. The new convective velocity scale may be extended to water-modeling studies of other buoyancy-driven airflows.
Original languageEnglish
Pages (from-to)2151 - 2164
Number of pages14
JournalJournal of Applied Meteorology and Climatology
Issue number10
Publication statusPublished - 2016
Externally publishedYes


All Science Journal Classification (ASJC) codes

  • Atmospheric Science

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