Boundary-Layer Meteorology

, Volume 146, Issue 3, pp 469–496 | Cite as

Intra-City Variation in Urban Morphology and Turbulence Structure in Helsinki, Finland

  • Annika NordboEmail author
  • Leena Järvi
  • Sami Haapanala
  • Joonas Moilanen
  • Timo Vesala


Most atmospheric boundary-layer theories are developed over vegetative surfaces and their applicability at urban sites is questionable. Here, we study the intra-city variation of turbulence characteristics and the applicability of boundary-layer theory using building-morphology data across Helsinki, and eddy-covariance data from three sites: two in central Helsinki (400 m apart) and one 4 km away from the city centre. The multi-site measurements enable the analysis of the horizontal scales at which quantities that characterize turbulent transport vary: (i) Roughness characteristics vary at a 10-m scale, and morphometric estimation of surface-roughness characteristics is shown to perform better than the often used rule-of-thumb estimates (average departures from the logarithmic wind profile are 14 and 44 %, respectively). (ii) The drag coefficient varies at a 100-m scale, and we provide an updated parametrization of the drag coefficient as a function of z/z H (the ratio of the measurement height to the mean building height). (iii) The transport efficiency of heat, water vapour and CO2 is shown to be weaker the more heterogeneous the site is, in terms of sources and sinks, and strong scalar dissimilarity is observed at all sites. (iv) Atmospheric stability varies markedly even within 4 km across the city: the median difference in nocturnal sensible heat fluxes between the three sites was over 50W m−2. Furthermore, (v) normalized power spectra and cospectra do not vary between sites, and they follow roughly the canonical theory as developed over vegetated terrain.


Drag Eddy covariance Roughness Turbulence Urban site 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Al-Jiboori MH, Xu YM, Qian YF (2002) Local similarity relationships in the urban boundary layer. Boundary-Layer Meteorol 102: 63–82CrossRefGoogle Scholar
  2. 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: 1–26. doi: 10.1002/joc.859 CrossRefGoogle Scholar
  3. Arya SP (2001) Introduction to micrometeorology. Academic Press, New York, 420 ppGoogle Scholar
  4. Aubinet M, Grelle A, Ibrom A, Rannik Ü, Moncrieff J, Foken T, Kowalski AS, Martin PH, Berbigier P, Bernhofer C, Clement R, Elbers J, Granier A, Grunwald T, Morgenstern K, Pilegaard K, Rebmann C, Snijders W, Valentini R, Vesala T (2000) Estimates of the annual net carbon and water exchange of forests: the EUROFLUX methodology. Adv Ecol Res 30: 113–175CrossRefGoogle Scholar
  5. Barlow JF, Harrison J, Robins AG, Wood CR (2011) A wind-tunnel study of flow distortion at a meteorological sensor on top of the BT tower, London, UK. J Wind Eng Ind Aerodyn 99: 899–907CrossRefGoogle Scholar
  6. Burba GG, Mcdermitt DK, Anderson DJ, Furtaw MD, Eckles RD (2010) Novel design of an enclosed CO2/H2O gas analyser for eddy covariance flux measurements. Tellus Ser B 62: 743–748. doi: 10.1111/j.1600-0889.2010.00468.x CrossRefGoogle Scholar
  7. Cava D, Katul GG (2012) On the scaling laws of the velocity-scalar co-spectra in the canopy sublayer above tall forests. Boundary-Layer Meteorol (online first). doi: 10.1007/s10546-012-9737-2
  8. Christen A, Vogt R (2004) Energy and radiation balance of a central European city. Int J Climatol 24: 1395–1421. doi: 10.1002/joc.1074 CrossRefGoogle Scholar
  9. Coutts AM, Beringer J, Tapper NJ (2007) Impact of increasing urban density on local climate: spatial and temporal variations in the surface energy balance in Melbourne, Australia. J Appl Meteorol Climatol 46: 477–493. doi: 10.1175/JAM2462.1 CrossRefGoogle Scholar
  10. Drebs A, Nordlund A, Karlsson P, Helminen J, Rissanen P (2002) Tilastoja Suomen ilmastosta 1971–2000 [Climatological statistics of Finland 1971–2000]. Finnish Meteorological Institute, HelsinkiGoogle Scholar
  11. Foken T, Wichura B (1996) Tools for quality assessment of surface-based flux measurements. Agric For Meteorol 78: 83–105CrossRefGoogle Scholar
  12. Foken T, Aubinet M, Leuning R (2012) The eddy covariance method. In: Aubinet M, Vesala T, Papale D (eds) Eddy covariance—a practical guide to measurement and data analysis. Springer Atmospheric Sciences, Dordrecht, pp 1–19Google Scholar
  13. Fortuniak K (2009) Selected characteristics of the atmospheric turbulence over a central European city centre—integral statistics. In: The seventh international conference on urban climate, 29 June–3 July 2009, Yokohama, JapanGoogle Scholar
  14. Garratt JR (1992) The atmospheric boundary layer. Cambridge University Press, UK, 316 ppGoogle Scholar
  15. Grimmond CSB, Oke TR (1999) Aerodynamic properties of urban areas derived, from analysis of surface form. J Appl Meteorol 38: 1262–1292CrossRefGoogle Scholar
  16. Grimmond CSB, King TS, Cropley FD, Nowak DJ, Souch C (2002) Local-scale fluxes of carbon dioxide in urban environments: methodological challenges and results from Chicago. Environ Pollut 116: S243–S254. doi: 10.1016/S0269-7491(01)00256-1 CrossRefGoogle Scholar
  17. Grimmond CSB, Salmond JA, Oke TR, Offerle B, Lemonsu A (2004) Flux and turbulence measurements at a densely built-up site in Marseille: heat, mass (water and carbon dioxide), and momentum. J Geophys Res Atmos 109: D24101. doi: 10.1029/2004JD004936 CrossRefGoogle Scholar
  18. Hagishima A, Tanimoto J, Nagayama K, Meno S (2009) Aerodynamic parameters of regular arrays of rectangular blocks with various geometries. Boundary-Layer Meteorol 132: 315–337. doi: 10.1007/s10546-009-9403-5 CrossRefGoogle Scholar
  19. Hanna SR, Zhou Y (2009) Space and time variations in turbulence during the Manhattan midtown 2005 field experiment. J Appl Meteorol Climatol 48: 2295–2304. doi: 10.1175/2009JAMC2046.1 CrossRefGoogle Scholar
  20. Helfter C, Famulari D, Phillips GJ, Barlow JF, Wood CR, Grimmond CSB, Nemitz E (2011) Controls of carbon dioxide concentrations and fluxes above central London. Atmos Chem Phys 11: 1913–1928. doi: 10.5194/acp-11-1913-2011 CrossRefGoogle Scholar
  21. Hill RJ (1989) Implications of Monin–Obukhov similarity theory for scalar quantities. J Atmos Sci 46: 2234–2244Google Scholar
  22. HSY (2008) Seutu CD—a dataset by the Helsinki region environmental services authorityGoogle Scholar
  23. Järvi L, Mammarella I, Eugster W, Ibrom A, Siivola E, Dellwik E, Keronen P, Burba G, Vesala T (2009a) Comparison of net CO2 fluxes measured with open- and closed-path infrared gas analyzers in an urban complex environment. Boreal Environ Res 14: 499–514Google Scholar
  24. Järvi L, Hannuniemi H, Hussein T, Junninen H, Aalto PP, Hillamo R, Mäkelä T, Keronen P, Siivola E, Vesala T, Kulmala M (2009b) The urban measurement station SMEAR III: continuous monitoring of air pollution and surface–atmosphere interactions in Helsinki, Finland. Boreal Environ Res 14: 86–109Google Scholar
  25. Järvi L, Nordbo A, Junninen H, Riikonen A, Moilanen J, Nikinmaa E, Vesala T (2012) Seasonal and annual variation of carbon dioxide surface fluxes in Helsinki, Finland, in 2006–2010. Atmos Chem Phys 12: 8475–8489CrossRefGoogle Scholar
  26. Kaimal JC, Finnigan JJ (1994) Atmospheric boundary layer flows, their structure and measurements. Oxford University Press, New York, 289 ppGoogle Scholar
  27. Kaimal JC, Izumi Y, Wyngaard JC, Cote R (1972) Spectral characteristics of surface-layer turbulence. Q J R Meteorol Soc 98: 563–589CrossRefGoogle Scholar
  28. Kanda M, Moriwaki R, Kasamatsu F (2006) Spatial variability of both turbulent fluxes and temperature profiles in an urban roughness layer. Boundary-Layer Meteorol 121: 339–350. doi: 10.1007/s10546-006-9063-7 CrossRefGoogle Scholar
  29. Katul G, Goltz S, Hsieh C, Cheng Y, Mowry F, Sigmon J (1995) Estimation of surface heat and momentum fluxes using the flux–variance method above uniform and nonuniform terrain. Boundary-Layer Meteorol 74: 237–260. doi: 10.1007/BF00712120 CrossRefGoogle Scholar
  30. Kormann R, Meixner F (2001) An analytical footprint model for non-neutral stratification. Boundary-Layer Meteorol 99: 207–224. doi: 10.1023/A:1018991015119 CrossRefGoogle Scholar
  31. Lenschow DH, Mann J, Kristensen L (1994) How long is long enough when measuring fluxes and other turbulence statistics. J Atmos Ocean Technol 11: 661–673CrossRefGoogle Scholar
  32. Li QS, Zhi L, Hu F (2010) Boundary layer wind structure from observations on a 325 m tower. J Wind Eng Ind Aerodyn 98: 818–832. doi: 10.1016/j.jweia.2010.08.001 CrossRefGoogle Scholar
  33. Lilleberg I, Hellman T (2011) The development of traffic in Helsinki in 2010 (in Finnish). Helsinki City Plann Dep 2: 1–70Google Scholar
  34. Liu HP, Peters G, Foken T (2001) New equations for sonic temperature variance and buoyancy heat flux with an omnidirectional sonic anemometer. Boundary-Layer Meteorol 100: 459–468CrossRefGoogle Scholar
  35. Liu G, Sun J, Jiang W (2009) Observational verification of urban surface roughness parameters derived from morphological models. Meteorol Appl 16: 205–213. doi: 10.1002/met.109 CrossRefGoogle Scholar
  36. MacDonald RW, Griffiths RF, Hall DJ (1998) An improved method for the estimation of surface roughness of obstacle arrays. Atmos Environ 32: 1857–1864CrossRefGoogle Scholar
  37. McBean G (1970) The turbulent transfer mechanisms in the atmospheric surface layer. PhD thesis at the University of British ColumbiaGoogle Scholar
  38. Metek (2006) USA-1 user manual, pp 1–55Google Scholar
  39. Monin AS, Obukhov AM (1954) Dimensionless characteristics of turbulence in the surface layer. Akad Nauk SSR 24: 163–187Google Scholar
  40. Monin AS, Yaglom AM (1975) Statistical fluid mechanics. MIT Press, Cambridge, 875 ppGoogle Scholar
  41. Moriwaki R, Kanda M (2006) 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: 163–179. doi: 10.1007/s10546-005-9034-4 CrossRefGoogle Scholar
  42. Munger JW, Loescher HW, Luo H (2012) Measurement, tower, and site design considerations. In: Aubinet M, Vesala T, Papale D (eds) Eddy covariance—a practical guide to measurement and data analysis. Springer Atmospheric Sciences, Dordrecht, pp 21–58Google Scholar
  43. Nordbo A, Järvi L, Vesala T (2012) Revised eddy covariance flux calculation methodologies—effect on urban energy balance. Tellus Ser B 64:18184. doi: 10.3402/tellusb.v64i0.18184
  44. Oke TR (2006) Initial guidance to obtain representative meteorological observations at urban sites. In: Instrument and observing methods (IOM) 81. World Meteorological Organization, pp 1–51Google Scholar
  45. Panofsky HA, Tennekes H, Lenschow DH, Wyngaard JC (1977) The characteristics of turbulent velocity components in the surface layer under convective conditions. Boundary-Layer Meteorol 11: 355–361CrossRefGoogle Scholar
  46. Quan L, Hu F (2009) Relationship between turbulent flux and variance in the urban canopy. Meteorol Atmos Phys 104: 29–36. doi: 10.1007/s00703-008-0012-5 CrossRefGoogle Scholar
  47. Rannik Ü (1998) On the surface layer similarity at a complex forest site. J Geophys Res Atmos 103: 8685–8697. doi: 10.1029/98JD00086 CrossRefGoogle Scholar
  48. Rannik Ü, Vesala T (1999) Autoregressive filtering versus linear detrending in estimation of fluxes by the eddy covariance method. Boundary-Layer Meteorol 91: 259–280CrossRefGoogle Scholar
  49. Rannik Ü, Keronen P, Hari P, Vesala T (2004) Estimation of forest-atmosphere CO2 exchange by eddy covariance and profile techniques. Agric For Meteorol 126: 141–155. doi: 10.1016/j.agrformet.2004.06.010 CrossRefGoogle Scholar
  50. Raupach MR (1979) Anomalies in flux–gradient relationships over forest. Boundary-Layer Meteorol 16: 467–486CrossRefGoogle Scholar
  51. Roth M (2000) Review of atmospheric turbulence over cities. Q J R Meteorol Soc 126: 941–990CrossRefGoogle Scholar
  52. 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
  53. Runkle BRK, Wille C, Gažovic M, Kutzbach L (2012) Attenuation correction procedures for water vapour fluxes from closed-path eddy-covariance systems. Boundary-Layer Meteorol 142(3): 401–423. doi: 10.1007/s10546-011-9689-y CrossRefGoogle Scholar
  54. Sofiev M, Genikhovich E, Keronen P, Vesala T (2010) Diagnosing the surface layer parameters for dispersion models within the meteorological-to-dispersion modeling interface. J Appl Meteorol Climatol 49: 221–233. doi: 10.1175/2009JAMC2210.1 CrossRefGoogle Scholar
  55. Stone B, Hess JJ, Frumkin H (2010) Urban form and extreme heat events: are sprawling cities more vulnerable to climate change than compact cities?. Environ Health Perspect 118: 1425–1428. doi: 10.1289/ehp.0901879 CrossRefGoogle Scholar
  56. Stull RB (1988) An introduction to boundary layer meteorology. Kluwer, Dordrecht, 666 ppGoogle Scholar
  57. Tillman JE (1972) The indirect determination of stability, heat and momentum fluxes in the atmospheric boundary layer from simple scalar variables during dry unstable conditions. J Appl Meteorol 11: 783–792CrossRefGoogle Scholar
  58. United Nations Population Division (2010) World urbanization prospects: the 2009 revision population database.
  59. van den Hurk BJJM, de Bruin HAR (1995) Fluctuations of the horizontal wind under unstable conditions. Boundary-Layer Meteorol 74: 341–352CrossRefGoogle Scholar
  60. Velasco E, Roth M (2010) Cities as net sources of CO2: review of atmospheric CO2 exchange in urban environments measured by eddy covariance technique. Geogr Compass 4: 1238–1259CrossRefGoogle Scholar
  61. Vesala T, Kljun N, Rannik Ü, Rinne J, Sogachev A, Markkanen T, Sabelfeld K, Foken T, Leclerc MY (2008a) Flux and concentration footprint modelling: state of the art. Environ Pollut 152: 653–666. doi: 10.1016/j.envpol.2007.06.070 CrossRefGoogle Scholar
  62. Vesala T, Järvi L, Launiainen S, Sogachev A, Rannik Ü, Mammarella I, Siivola E, Keronen P, Rinne J, Riikonen A, Nikinmaa E (2008b) Surface–atmosphere interactions over complex urban terrain in Helsinki, Finland. Tellus Ser B 60: 188–199. doi: 10.1111/j.1600-0889.2007.00312.x CrossRefGoogle Scholar
  63. Vogt R, Christen A, Rotach MW, Roth M, Satyanarayana ANV (2006) Temporal dynamics of CO2 fluxes and profiles over a central European city. Theor Appl Climatol 84: 117–126. doi: 10.1007/s00704-005-0149-9 CrossRefGoogle Scholar
  64. Weaver H (1990) Temperature and humidity flux–variance relations determined by one-dimensional eddy-correlation. Boundary-Layer Meteorol 53: 77–91. doi: 10.1007/BF00122464 CrossRefGoogle Scholar
  65. Webb EK, Pearman GI, Leuning R (1980) Correction of flux measurements for density effects due to heat and water-vapor transfer. Q J R Meteorol Soc 106: 85–100CrossRefGoogle Scholar
  66. Weber S, Kordowski K (2010) Comparison of atmospheric turbulence characteristics and turbulent fluxes from two urban sites in Essen, Germany RID E-7434-2011. Theor Appl Climatol 102: 61–74. doi: 10.1007/s00704-009-0240-8 CrossRefGoogle Scholar
  67. Wienhold FG, Frahm H, Harris GW (1994) Measurements of N2O fluxes from fertilized grassland using a fast-response tunable diode-laser spectrometer. J Geophys Res Atmos 99: 16557–16567CrossRefGoogle Scholar
  68. Wood CR, Arnold SJ, Balogun AA, Barlow JF, Belcher SE, Britter RE, Cheng H, Dobre A, Lingard JJN, Martin D, Neophytou MK, Petersson FK, Robins AG, Shallcross DE, Smalley RJ, Tate JE, Tomlin AS, White IR (2009) Dispersion experiments in central London—the 2007 Dapple project. Bull Am Meteorol Soc 90: 955–970. doi: 10.1175/2009BAMS2638.1 CrossRefGoogle Scholar
  69. 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: 77–96. doi: 10.1007/s10546-010-9516-xER CrossRefGoogle Scholar
  70. Wyngaard JC, Coté OR, Izumi Y (1971) Local free convection, similarity and the budgets of shear stress and heat flux. J Atmos Sci 28: 1171–1182CrossRefGoogle Scholar
  71. Zilitinkevich SS, Mammarella I, Baklanov AA, Joffre SM (2008) The effect of stratification on the aerodynamic roughness length and displacement height. Boundary-Layer Meteorol 129: 179–190. doi: 10.1007/s10546-008-9307-9 CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2012

Authors and Affiliations

  • Annika Nordbo
    • 1
    Email author
  • Leena Järvi
    • 1
  • Sami Haapanala
    • 1
  • Joonas Moilanen
    • 1
  • Timo Vesala
    • 1
  1. 1.Department of PhysicsUniversity of HelsinkiHelsinkiFinland

Personalised recommendations