Numerical modeling of the nocturnal urban boundary layer

Itsushi Uno, H. Ueda, S. Wakamatsu

Research output: Contribution to journalArticle

56 Citations (Scopus)

Abstract

A numerical case study with a second-order turbulence closure model is proposed to study the role of urban canopy layer (UCL) for the formation of the nocturnal urban boundary layer (UBL). The turbulent diffusion coefficient was determined from an algebraic stress model. The concept of urban building surface area density is proposed to represent the UCL. Calculated results were also compared with field observation data. The height of the elevated inversion above an urban center was simulated and found to be approximately twice the average building height. The turbulent kinetic energy k, energy dissipation rate ε, and turbulence intensities 〈u2〉 and 〈w2〉 increase rapidly at the upwind edge of the urban area. The Reynolds stress 〈uw〉 displayed a nearly uniform profile inside the UBL, and the vertical sensible heat flux 〈wθ〉 had a negative value at the inversion base height. This indicates that the downward transport of sensible heat from the inversion base may play an important role in the formation of the nocturnal UBL.

Original languageEnglish
Pages (from-to)77-98
Number of pages22
JournalBoundary-Layer Meteorology
Volume49
Issue number1-2
DOIs
Publication statusPublished - Oct 1 1989
Externally publishedYes

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boundary layer
turbulence
canopy
modeling
turbulent diffusion
sensible heat flux
energy dissipation
kinetic energy
surface area
urban area
inversion
rate

All Science Journal Classification (ASJC) codes

  • Atmospheric Science

Cite this

Numerical modeling of the nocturnal urban boundary layer. / Uno, Itsushi; Ueda, H.; Wakamatsu, S.

In: Boundary-Layer Meteorology, Vol. 49, No. 1-2, 01.10.1989, p. 77-98.

Research output: Contribution to journalArticle

Uno, Itsushi ; Ueda, H. ; Wakamatsu, S. / Numerical modeling of the nocturnal urban boundary layer. In: Boundary-Layer Meteorology. 1989 ; Vol. 49, No. 1-2. pp. 77-98.
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