Skip to main content
SpringerLink
Log in

Coherent Flow Structures and Pollutant Dispersion in a Street Canyon

  • Research Article
  • Published:
Boundary-Layer Meteorology Aims and scope Submit manuscript

Abstract

Coherent flow structures and pollutant dispersion in a spanwise-long street canyon are investigated using a parallelized large-eddy-simulation model. Low- and high-concentration branches, starting from the downwind top corner and upwind bottom corner, respectively, are detected in the time-averaged field of pollutant concentration, and detailed structures of in-canyon flow and pollutant dispersion following the two branches are demonstrated. When turbulent eddies impinge on the upper downwind wall, low- and high-concentration blobs with U-shaped flow structures appear and move downward. The downdrafts tilt away from the downwind bottom corner and impinge on the canyon bottom, driving horizontally diverging flows. Cellular structures of low-concentration centres and high-concentration edges are induced by the downdrafts and diverging flows. The diverging flows push low-concentration air toward the downwind and upwind building walls, resulting in local divergence and convergence of pollutants on both walls. Time series of pollutant concentration at multiple points illustrate that pollutant concentration at the pedestrian level is highly sensitive to the diverging flows. The multiresolution spectra show that time scales of variations of pollutant concentration and vertical velocity component increase from the canyon top to the pedestrian-level centre, indicating longer time-scale flow structures are dominant inside the street canyon. The multiresolution cospectra also show that the time scale of vertical turbulent transport of pollutants increases from the canyon top to the pedestrian-level centre. At the two bottom corners, however, short and long time-scale transports occur together, confirming that the low-concentration diverging flows transport pollutants downward while short time-scale turbulence transports pollutants upward.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9

Similar content being viewed by others

References

  • Arakawa A, Lamb VR (1977) Computational design of the basic dynamical processes of the UCLA general circulation model. Methods Comput Phys 17:173–265

    Google Scholar 

  • Baik JJ, Kim JJ (1999) A numerical study of flow and pollutant dispersion characteristics in urban street canyons. J Appl Meteorol 38(11):1576–1589

    Article  Google Scholar 

  • Baik JJ, Kim JJ (2002) On the escape of pollutants from urban street canyons. Atmos Environ 36(3):527–536

    Article  Google Scholar 

  • Belcher SE (2005) Mixing and transport in urban areas. Philos Trans R Soc 363(1837):2947–2968

    Article  Google Scholar 

  • Belcher SE, Coceal O, Goulart EV, Rudd AC, Robins AG (2015) Processes controlling atmospheric dispersion through city centres. J Fluid Mech 763:51–81

    Article  Google Scholar 

  • Britter RE, Hanna SR (2003) Flow and dispersion in urban areas. Annu Rev Fluid Mech 35:469–496

    Article  Google Scholar 

  • Caton F, Britter R, Dalziel S (2003) Dispersion mechanisms in a street canyon. Atmos Environ 37(5):693–702

    Article  Google Scholar 

  • Cui Z, Cai X, Baker CJ (2004) Large-eddy simulation of turbulent flow in a street canyon. Q J R Meteorol Soc 130(599):1373–1394

    Article  Google Scholar 

  • Deardorff JW (1980) Stratocumulus-capped mixed layers derived from a three-dimensional model. Boundary-Layer Meteorol 18(4):495–527

    Article  Google Scholar 

  • Duan G, Jackson JG, Ngan K (2019) Scalar mixing in an urban canyon. Environ Fluid Mech 19(4):911–939

    Article  Google Scholar 

  • Eliasson I, Offerle B, Grimmond CSB, Lindqvist S (2006) Wind fields and turbulence statistics in an urban street canyon. Atmos Environ 40(1):1–16

    Article  Google Scholar 

  • Gentine P, Garelli A, Park SB, Nie J, Torri G, Kuang Z (2016) Role of surface heat fluxes underneath cold pools. Geophys Res Lett 43(2):874–883

    Article  Google Scholar 

  • Han BS, Baik JJ, Kwak KH, Park SB (2018) Large-eddy simulation of reactive pollutant exchange at the top of a street canyon. Atmos Environ 187:381–389

    Article  Google Scholar 

  • Howell JF, Mahrt L (1997) Multiresolution flux decomposition. Boundary-Layer Meteorol 83(1):117–137

    Article  Google Scholar 

  • Kwak KH, Lee SH, Seo JM, Park SB, Baik JJ (2016) Relationship between rooftop and on-road concentrations of traffic-related pollutants in a busy street canyon: ambient wind effects. Environ Pollut 208:185–197

    Article  Google Scholar 

  • Letzel MO, Krane M, Raasch S (2008) High resolution urban large-eddy simulation studies from street canyon to neighbourhood scale. Atmos Environ 42(38):8770–8784

    Article  Google Scholar 

  • Lo KW, Ngan K (2017) Characterizing ventilation and exposure in street canyons using Lagrangian particles. J Appl Meteorol Climatol 56(5):1177–1194

    Article  Google Scholar 

  • Maronga B, Moene AF, van Dinther D, Raasch S, Bosveld FC, Gioli B (2013) Derivation of structure parameters of temperature and humidity in the convective boundary layer from large-eddy simulations and implications for the interpretation of scintillometer observations. Boundary-Layer Meteorol 148(1):1–30

    Article  Google Scholar 

  • Maronga B, Gryschka M, Heinze R, Hoffmann F, Kanani-Sühring F, Keck M, Ketelsen K, Letzel MO, Sühring M, Raasch S (2015) The Parallelized Large-Eddy Simulation Model (PALM) version 4.0 for atmospheric and oceanic flows: model formulation, recent developments, and future perspectives. Geosci Model Dev 8(8):2515–2551

    Article  Google Scholar 

  • Maronga B, Banzhaf S, Burmeister C, Esch T, Forkel R, Fröhlich D, Fuka V, Gehrke KF, Geletič J, Giersch S, Gronemeier T, Groß G, Heldens W, Hellsten A, Hoffmann F, Inagaki A, Kadasch E, Kanani-Sühring F, Ketelsen K, Khan BA, Knigge C, Knoop H, Krč P, Kurppa M, Maamari H, Matzarakis A, Mauder M, Pallasch M, Pavlik D, Pfafferott J, Resler J, Rissmann S, Russo E, Salim M, Schrempf M, Schwenkel J, Seckmeyer G, Schubert S, Sühring M, von Tils R, Vollmer L, Ward S, Witha B, Wurps H, Zeidler J, Raasch S (2020) Overview of the PALM model system 6.0. Geosci Model Dev 13(3):1335–1372

    Article  Google Scholar 

  • Marshall JD, Brauer M, Frank LD (2009) Healthy neighborhoods: walkability and air pollution. Environ Health Perspect 117(11):1752–1759

    Article  Google Scholar 

  • McWilliams JC (1990) A demonstration of the suppression of turbulent cascades by coherent vortices in two-dimensional turbulence. Phys Fluids A 2(4):547–552

    Article  Google Scholar 

  • Michioka T, Sato A (2012) Effect of incoming turbulent structure on pollutant removal from two-dimensional street canyon. Boundary-Layer Meteorol 145(3):469–484

    Article  Google Scholar 

  • Oke TR (1988) Street design and urban canopy layer climate. Energy Buil 11(1–3):103–113

    Article  Google Scholar 

  • Oke TR, Mills G, Christen A, Voogt JA (2017) Urban climates. Cambridge University Press, Cambridge

    Book  Google Scholar 

  • Oleson KW, Bonan B, Feddema J, Vertenstein M, Grimmond CSB (2008) An urban parameterization for a global climate model. Part I: formulation and evaluation for two cities. J Appl Meteorol Climatol 47(4):1038–1060

    Article  Google Scholar 

  • Park SB, Baik JJ, Raasch S, Letzel MO (2012) A large-eddy simulation study of thermal effects on turbulent flow and dispersion in and above a street canyon. J Appl Meteorol Climatol 51(5):829–841

    Article  Google Scholar 

  • Park SB, Baik JJ, Ryu YH (2013) A large-eddy simulation study of bottom-heating effects on scalar dispersion in and above a cubical building array. J Appl Meteorol Climatol 52(8):1738–1752

    Article  Google Scholar 

  • Park SB, Baik JJ, Lee SH (2015) Impacts of mesoscale wind on turbulent flow and ventilation in a densely built-up urban area. J Appl Meteorol Climatol 54(4):811–824

    Article  Google Scholar 

  • Park SB, Böing S, Gentine P (2018) Role of surface friction on shallow nonprecipitating convection. J Atmos Sci 75(1):163–178

    Article  Google Scholar 

  • Pavageau M, Schatzmann M (1999) Wind tunnel measurements of concentration fluctuations in an urban street canyon. Atmos Environ 33(24–25):3961–3971

    Article  Google Scholar 

  • Rotach M (1995) Profiles of turbulence statistics in and above an urban street canyon. Atmos Environ 29(13):1473–1486

    Article  Google Scholar 

  • Ryu YH, Baik JJ, Lee SH (2011) A new single-layer urban canopy model for use in mesoscale atmospheric models. J Appl Meteorol Climatol 50(9):1773–1794

    Article  Google Scholar 

  • Sini JF, Anquetin S, Mestayer PG (1996) Pollutant dispersion and thermal effects in urban street canyons. Atmos Environ 30(15):2659–2677

    Article  Google Scholar 

  • Uehara K, Murakami S, Oikawa S, Wakamatsu S (2000) Wind tunnel experiments on how thermal stratification affects flow in and above urban street canyons. Atmos Environ 34(10):1553–1562

    Article  Google Scholar 

  • Vickers D, Mahrt L (2003) The cospectral gap and turbulent flux calculations. J Atmos Ocean Tech 20(5):660–672

    Article  Google Scholar 

  • Walton A, Cheng A (2002) Large-eddy simulation of pollution dispersion in an urban street canyon–part II: idealised canyon simulation. Atmos Environ 36(22):3615–3627

    Article  Google Scholar 

  • Wicker LJ, Skamarock WC (2002) Time-splitting methods for elastic models using forward time schemes. Mon Weather Rev 130(8):2088–2097

    Article  Google Scholar 

  • Williamson J (1980) Low-storage Runge–Kutta schemes. J Comput Phys 35(1):48–56

    Article  Google Scholar 

  • Xie ZT, Castro IP (2006) LES and RANS for turbulent flow over arrays of wall-mounted obstacles. Flow Turbul Combust 76(3):291–312

    Article  Google Scholar 

  • Xie ZT, Castro IP (2009) Large-eddy simulation for flow and dispersion in urban streets. Atmos Environ 43(13):2174–2185

    Article  Google Scholar 

  • Yaghoobian N, Kleissl J, Paw U KT (2014) An improved three-dimensional simulation of the diurnally varying street-canyon flow. Boundary-Layer Meteorol 153(2):251–276

    Article  Google Scholar 

  • Zhong J, Cai XM, Bloss WJ (2015) Modelling the dispersion and transport of reactive pollutants in a deep urban street canyon: using large-eddy simulation. Environ Pollut 200:42–52

    Article  Google Scholar 

Download references

Acknowledgements

The authors are grateful to two anonymous reviewers for providing valuable comments on this study. This work was supported by the Research Institute of Basic Sciences funded by the National Research Foundation of Korea (NRF-2019R1A6A1A10073437), and by the Small Grant for Exploratory Research (SGER) program through the National Research Foundation of Korea (NRF-2018R1D1A1A02086007).

Author information

Authors and Affiliations

  1. School of Environmental Engineering, University of Seoul, Seoul, South Korea

    Seung-Bu Park

  2. School of Earth and Environmental Sciences, Seoul National University, Seoul, South Korea

    Jong-Jin Baik

  3. Department of Biological and Environmental Engineering, Semyung University, Jecheon, South Korea

    Beom-Soon Han

Authors
  1. Seung-Bu Park
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Jong-Jin Baik
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Beom-Soon Han
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Jong-Jin Baik.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Park, SB., Baik, JJ. & Han, BS. Coherent Flow Structures and Pollutant Dispersion in a Street Canyon. Boundary-Layer Meteorol 182, 363–378 (2022). https://doi.org/10.1007/s10546-021-00669-3

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10546-021-00669-3

Keywords

Search

Navigation