Flux Similarity and Turbulent Transport of Momentum, Heat and Carbon Dioxide in the Urban Boundary Layer

  • M. SchmutzEmail author
  • R. Vogt
Research Article


Turbulence characteristics in the urban boundary layer of a mid-latitude European city are investigated using a quadrant analysis of more than 12 years of eddy-covariance measurements at 39 m above street level. To describe the ongoing turbulent-exchange processes, particularly the properties of ejection and sweep events, presented here are the transfer efficiency and the similarity of momentum, heat, CO2 and H2O fluxes. In addition, an event-detection algorithm is applied to derive information on the importance of organized structures for the turbulent exchange, finding that momentum and heat fluxes are primarily controlled by atmospheric stability, whereas CO2 and H2O fluxes are more affected by the presence of active sources of the corresponding scalars (e.g. traffic for CO2 fluxes). The transfer efficiencies of momentum and heat can thus be modelled accurately, but the prediction for CO2 and H2O fluxes fails because of scalar dissimilarity. Generally, ejections are more important under buoyancy-driven unstable conditions and responsible for large structures, and sweeps are more characteristic of stable cases and smaller structures. The quadrant statistics enable the identification of scales between a hole-size factor of 10 and 20 where turbulent exchange is especially efficient and almost solely takes place by ejection–sweep cycles. This information is used to apply an event-detection algorithm, which quantifies flux fractions of such reoccurring structures to be around 0.5–0.8, with the time fraction being usually around 0.1.


Flux similarity Long-term measurements Quadrant analysis Transport and transfer efficiency Urban boundary layer 



This research is funded from the project “Urban Climate Study of Bucharest” (IZERZ0_142160) made possible by the Romanian–Swiss Research Program. Special thanks go to E. Parlow and C. Feigenwinter from the MCR–Lab for supporting this research. The data used are listed in the references or available from the MCR–Lab on request (


  1. Arnfield AJ (2003) Two decades of urban climate research: a review of turbulence, exchanges of energy and water, and the urban heat island. Int J Climatol 23:1–26CrossRefGoogle Scholar
  2. Barthlott C, Drobinski P, Fesquet C, Dubos T, Pietras C (2007) Long-term study of coherent structures in the atmospheric surface layer. Boundary-Layer Meteorol 125:1–24CrossRefGoogle Scholar
  3. Boppe RS, Neu WL, Shuai H (1999) Large-scale motions in the marine atmospheric aurface layer. Boundary-Layer Meteorol 92:165–183CrossRefGoogle Scholar
  4. Christen A, van Gorsel E, Vogt R (2007) Coherent structures in urban roughness sublayer turbulence. Int J Climatol 27:1955–1968CrossRefGoogle Scholar
  5. De Bruin HAR, Kohsiek W, Van Den Hurk BJJM (1993) A verification of some methods to determine the fluxes of momentum, sensible heat, and water vapour using standard deviation and structure parameter of scalar meteorological quantities. Boundary-Layer Meteorol 63:231–257CrossRefGoogle Scholar
  6. Dupont S, Patton EG (2012) Momentum and scalar transport within a vegetation canopy following atmospheric stability and seasonal canopy changes: the CHATS experiment. Atmos Chem Phys 12:5913–5935CrossRefGoogle Scholar
  7. Etling D, Brown RA (1993) Roll vortices in the planetary boundary layer: a review. Boundary-Layer Meteorol 65:215–248CrossRefGoogle Scholar
  8. Feigenwinter C, Vogt R, Parlow E (1999) Vertical structure of selected turbulence characteristics above an urban canopy. Theor Appl Climatol 62:51–63CrossRefGoogle Scholar
  9. Foken T (2017) Micrometeorology. Springer-Verlag, Berlin HeidelbergCrossRefGoogle Scholar
  10. Francone C, Katul GG, Cassardo C, Richiardone R (2012) Turbulent transport efficiency and the ejection-sweep motion for momentum and heat on sloping terrain covered with vineyards. Agric For Meteorol 162–163:98–107CrossRefGoogle Scholar
  11. Grimmond CSB, Oke TR (1999) Aerodynamic properties of urban areas derived from analysis of surface form. J Appl Meteorol 38:1262–1292CrossRefGoogle Scholar
  12. Hommema SE, Adrian RJ (2003) Packet structure of surface eddies in the atmospheric boundary layer. Boundary-Layer Meteorol 106:147–170CrossRefGoogle Scholar
  13. Hutchins N, Marusic I (2007) Evidence of very long meandering features in the logarithmic region of turbulent boundary layers. J Fluid Mech 579:1–28CrossRefGoogle Scholar
  14. Kaimal JC, Gaynor JE (1991) Another look at sonic thermometry. Boundary-Layer Meteorol 56:401–410CrossRefGoogle Scholar
  15. Katul G, Hsieh C-I, Kuhn G, Ellsworth D, Nie D (1997a) Turbulent eddy motion at the forest-atmosphere interface. J Geophys Res Atmos 102:13409–13421CrossRefGoogle Scholar
  16. Katul G, Kuhn G, Schieldge J, Hsieh C-I (1997b) The ejection-sweep character of scalar fluxes in the unstable surface layer. Boundary-Layer Meteorol 83:1–26CrossRefGoogle Scholar
  17. Kurppa M, Nordbo A, Haapanala S, Järvi L (2015) Effect of seasonal variability and land use on particle number and CO2 exchange in Helsinki, Finland. Urban Clim 13:94–109CrossRefGoogle Scholar
  18. Lee X, Yu Q, Sun X, Liu J, Min Q, Liu Y, Zhang X (2004) Micrometeorological fluxes under the influence of regional and local advection: a revisit. Agric For Meteorol 122:111–124CrossRefGoogle Scholar
  19. Li D, Bou-Zeid E (2011) Coherent structures and the dissimilarity of turbulent transport of momentum and scalars in the unstable atmospheric surface layer. Boundary-Layer Meteorol 140:243–262CrossRefGoogle Scholar
  20. Lietzke B, Vogt R (2013) Variability of CO2 concentrations and fluxes in and above an urban street canyon. Atmos Environ 74:60–72CrossRefGoogle Scholar
  21. Lu SS, Willmarth WW (1973) Measurements of the structure of the Reynolds stress in a turbulent boundary layer. J Fluid Mech 60:481CrossRefGoogle Scholar
  22. Luchik TS, Tiederman WG (1987) Timescale and structure of ejections and bursts in turbulent channel flows. J Fluid Mech 174:529CrossRefGoogle Scholar
  23. Maitani T, Ohtaki E (1987) Turbulent transport processes of momentum and sensible heat in the surface layer over a paddy field. Boundary-Layer Meteorol 40:283–293CrossRefGoogle Scholar
  24. Mason PJ, Sykes RI (1980) A two-dimensional numerical study of horizontal roll vortices in the neutral atmospheric boundary layer. Q J R Meteorol Soc 106:351–366CrossRefGoogle Scholar
  25. Mohr M, Schindler D (2016) Coherent momentum exchange above and within a scots pine forest. Atmosphere 7:61CrossRefGoogle Scholar
  26. Moriwaki R, Kanda M (2005) Local and global similarity in turbulent transfer of heat, water vapour, and CO2 in the dynamic convective sublayer over a suburban area. Boundary-Layer Meteorol 120:163–179CrossRefGoogle Scholar
  27. Nordbo A, Järvi L, Haapanala S, Moilanen J, Vesala T (2012) Intra-city variation in urban morphology and turbulence structure in Helsinki, Finland. Boundary-Layer Meteorol 146:469–496CrossRefGoogle Scholar
  28. Raupach MR, Coppin PA, Legg BJ (1986) Experiments on scalar dispersion within a model plant canopy part I: the turbulence structure. Boundary-Layer Meteorol 35:21–52CrossRefGoogle Scholar
  29. Roth M (2000) Review of atmospheric turbulence over cities. Q J R Meteorol Soc 126:941–990CrossRefGoogle Scholar
  30. Roth M, Oke TR (1995) Relative efficiencies of turbulent transfer of heat, mass, and momentum over a patchy urban surface. J Atmos Sci 52:1863–1874CrossRefGoogle Scholar
  31. Schmutz M, Vogt R, Feigenwinter C, Parlow E (2016) Ten years of eddy covariance measurements in Basel, Switzerland: seasonal and interannual variabilities of urban CO2 mole fraction and flux. J Geophys Res Atmos 121:8649–8667CrossRefGoogle Scholar
  32. Sempreviva AM, Højstrup J (1998) Transport of temperature and humidity variance and covariance in the marine surface layer. Boundary-Layer Meteorol 87:233–253CrossRefGoogle Scholar
  33. Shaw RH, Tavangar J, Ward DP (1983) Structure of the Reynolds stress in a canopy layer. J Climate Appl Meteor 22:1922–1931CrossRefGoogle Scholar
  34. Steiner AL, Pressley SN, Botros A, Jones E, Chung SH, Edburg SL (2011) Analysis of coherent structures and atmosphere-canopy coupling strength during the CABINEX field campaign. Atmos Chem Phys 11:11921–11936CrossRefGoogle Scholar
  35. Thomas C, Foken T (2007) Flux contribution of coherent structures and its implications for the exchange of energy and matter in a tall spruce canopy. Boundary-Layer Meteorol 123:317–337CrossRefGoogle Scholar
  36. Thomas C, Serafimovich A, Siebicke L, Gerken T, Foken T (2017) Coherent structures and flux coupling. In: Energy and matter fluxes of a spruce forest ecosystem. Springer, Berlin, pp 113–135Google Scholar
  37. Tyagi B, Satyanarayana ANV (2014) Coherent structures contributions in fluxes of momentum and heat at two tropical sites during pre-monsoon thunderstorm season. Int J Climatol 34:1575–1584CrossRefGoogle Scholar
  38. Wang L, Li D, Gao Z, Sun T, Guo X, Bou-Zeid E (2013) Turbulent transport of momentum and scalars above an urban canopy. Boundary-Layer Meteorol 150:485–511CrossRefGoogle Scholar
  39. Webb EK, Pearman GI, Leuning R (1980) Correction of flux measurements for density effects due to heat and water vapour transfer. Q J R Meteorol Soc 106:85–100CrossRefGoogle Scholar
  40. Williams CA, Scanlon TM, Albertson JD (2006) Influence of surface heterogeneity on scalar dissimilarity in the roughness sublayer. Boundary-Layer Meteorol 122:149–165CrossRefGoogle Scholar
  41. Wood CR, Lacser A, Barlow JF, Padhra A, Belcher SE, Nemitz E, Helfter C, Famulari D, Grimmond CSB (2010) Turbulent flow at 190 m height above london during 2006–2008: a climatology and the applicability of similarity theory. Boundary-Layer Meteorol 137:77–96CrossRefGoogle Scholar
  42. Wyngaard JC, Moeng C-H (1992) Parameterizing turbulent diffusion through the joint probability density. Boundary-Layer Meteorol 60:1–13CrossRefGoogle Scholar

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© Springer Nature B.V. 2019

Authors and Affiliations

  1. 1.Department of Environmental Sciences, Atmospheric Sciences, Research Group Meteorology, Climatology, and Remote SensingUniversity of BaselBaselSwitzerland

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