Surface-atmosphere interactions over complex urban terrain in Helsinki, Finland

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Sammanfattning

Long-term measurements of fluxes of sensible heat (H), latent heat (LE) and carbon dioxide (F-c) were made from December 2005 to August 2006 over an urban landscape in Helsinki, Finland using the direct micrometeorological eddy covariance technique. Three distinguished sectors of land-use cover (vegetation, roads and buildings) allowed comparisons of fluxes over different urban surfaces. The normalized standard deviation of wind and scalars as a function of atmospheric stability were typical for rough surfaces, as were turbulence spectra and cospectra. Footprint analysis was performed by a boundary-layer one and half-order closure model allowing for discrimination of surface and canopy sinks/sources and complex topography. Fluxes were analysed as average diurnal courses over winter, spring and summer periods. H exceeded LE reaching 300 W m(-2) over urban and road surfaces in the summer and it was close to 100 W m(-2) in the winter. LE was highest in the summer over vegetation cover attaining 150 W m(-2). The emission rate of CO2 was high over road sector [20 mu mol (m(2)s)(-1)][Correction added after online publication 16 Oct 2007: 30 mu mol changed to 20 mu mol] while in the vegetation sector it remained below 5 mu mol (m(2)s)(-1) and at summertime reached even -10 mu mol(m(2) s)(-1) [Correction added after online publication 16 Oct 2007: wording of sentence altered]. Effluxes from soil measured by chambers were 1-3 mu mol (m(2)s)(-1). F-c correlated with traffic density and a background non-vehicle flux was 1 mu mol (m(2)s)(-1) [Correction added after online publication 16 Oct 2007: 2 mu mol changed to 1 mu mol].
Originalspråkengelska
TidskriftTellus. Series B: Chemical and Physical Meteorology
Volym60
Utgåva2
Sidor (från-till)188-199
Antal sidor12
ISSN0280-6509
DOI
StatusPublicerad - 2008
MoE-publikationstypA1 Tidskriftsartikel-refererad

Vetenskapsgrenar

  • 411 Jordbruks- och skogsvetenskaper

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@article{c040462f32b0445aaedf81ff5af6a8b8,
title = "Surface-atmosphere interactions over complex urban terrain in Helsinki, Finland",
abstract = "Long-term measurements of fluxes of sensible heat (H), latent heat (LE) and carbon dioxide (F-c) were made from December 2005 to August 2006 over an urban landscape in Helsinki, Finland using the direct micrometeorological eddy covariance technique. Three distinguished sectors of land-use cover (vegetation, roads and buildings) allowed comparisons of fluxes over different urban surfaces. The normalized standard deviation of wind and scalars as a function of atmospheric stability were typical for rough surfaces, as were turbulence spectra and cospectra. Footprint analysis was performed by a boundary-layer one and half-order closure model allowing for discrimination of surface and canopy sinks/sources and complex topography. Fluxes were analysed as average diurnal courses over winter, spring and summer periods. H exceeded LE reaching 300 W m(-2) over urban and road surfaces in the summer and it was close to 100 W m(-2) in the winter. LE was highest in the summer over vegetation cover attaining 150 W m(-2). The emission rate of CO2 was high over road sector [20 mu mol (m(2)s)(-1)][Correction added after online publication 16 Oct 2007: 30 mu mol changed to 20 mu mol] while in the vegetation sector it remained below 5 mu mol (m(2)s)(-1) and at summertime reached even -10 mu mol(m(2) s)(-1) [Correction added after online publication 16 Oct 2007: wording of sentence altered]. Effluxes from soil measured by chambers were 1-3 mu mol (m(2)s)(-1). F-c correlated with traffic density and a background non-vehicle flux was 1 mu mol (m(2)s)(-1) [Correction added after online publication 16 Oct 2007: 2 mu mol changed to 1 mu mol].",
keywords = "411 Agriculture and forestry",
author = "Timo Vesala and Leena J{\"a}rvi and Samuli Launiainen and Andrey Sogachev and Ullar Rannik and Ivan Mammarella and Erkki Siivola and Petri Keronen and Janne Rinne and Anu Riikonen and Eero Nikinmaa",
year = "2008",
doi = "10.1111/j.1600-0889.2007.00312.x",
language = "English",
volume = "60",
pages = "188--199",
journal = "Tellus. Series B: Chemical and Physical Meteorology",
issn = "0280-6509",
publisher = "TAYLOR & FRANCIS LTD",
number = "2",

}

Surface-atmosphere interactions over complex urban terrain in Helsinki, Finland. / Vesala, Timo; Järvi, Leena; Launiainen, Samuli; Sogachev, Andrey; Rannik, Ullar; Mammarella, Ivan; Siivola, Erkki; Keronen, Petri; Rinne, Janne; Riikonen, Anu; Nikinmaa, Eero.

I: Tellus. Series B: Chemical and Physical Meteorology, Vol. 60, Nr. 2, 2008, s. 188-199.

Forskningsoutput: TidskriftsbidragArtikelVetenskapligPeer review

TY - JOUR

T1 - Surface-atmosphere interactions over complex urban terrain in Helsinki, Finland

AU - Vesala, Timo

AU - Järvi, Leena

AU - Launiainen, Samuli

AU - Sogachev, Andrey

AU - Rannik, Ullar

AU - Mammarella, Ivan

AU - Siivola, Erkki

AU - Keronen, Petri

AU - Rinne, Janne

AU - Riikonen, Anu

AU - Nikinmaa, Eero

PY - 2008

Y1 - 2008

N2 - Long-term measurements of fluxes of sensible heat (H), latent heat (LE) and carbon dioxide (F-c) were made from December 2005 to August 2006 over an urban landscape in Helsinki, Finland using the direct micrometeorological eddy covariance technique. Three distinguished sectors of land-use cover (vegetation, roads and buildings) allowed comparisons of fluxes over different urban surfaces. The normalized standard deviation of wind and scalars as a function of atmospheric stability were typical for rough surfaces, as were turbulence spectra and cospectra. Footprint analysis was performed by a boundary-layer one and half-order closure model allowing for discrimination of surface and canopy sinks/sources and complex topography. Fluxes were analysed as average diurnal courses over winter, spring and summer periods. H exceeded LE reaching 300 W m(-2) over urban and road surfaces in the summer and it was close to 100 W m(-2) in the winter. LE was highest in the summer over vegetation cover attaining 150 W m(-2). The emission rate of CO2 was high over road sector [20 mu mol (m(2)s)(-1)][Correction added after online publication 16 Oct 2007: 30 mu mol changed to 20 mu mol] while in the vegetation sector it remained below 5 mu mol (m(2)s)(-1) and at summertime reached even -10 mu mol(m(2) s)(-1) [Correction added after online publication 16 Oct 2007: wording of sentence altered]. Effluxes from soil measured by chambers were 1-3 mu mol (m(2)s)(-1). F-c correlated with traffic density and a background non-vehicle flux was 1 mu mol (m(2)s)(-1) [Correction added after online publication 16 Oct 2007: 2 mu mol changed to 1 mu mol].

AB - Long-term measurements of fluxes of sensible heat (H), latent heat (LE) and carbon dioxide (F-c) were made from December 2005 to August 2006 over an urban landscape in Helsinki, Finland using the direct micrometeorological eddy covariance technique. Three distinguished sectors of land-use cover (vegetation, roads and buildings) allowed comparisons of fluxes over different urban surfaces. The normalized standard deviation of wind and scalars as a function of atmospheric stability were typical for rough surfaces, as were turbulence spectra and cospectra. Footprint analysis was performed by a boundary-layer one and half-order closure model allowing for discrimination of surface and canopy sinks/sources and complex topography. Fluxes were analysed as average diurnal courses over winter, spring and summer periods. H exceeded LE reaching 300 W m(-2) over urban and road surfaces in the summer and it was close to 100 W m(-2) in the winter. LE was highest in the summer over vegetation cover attaining 150 W m(-2). The emission rate of CO2 was high over road sector [20 mu mol (m(2)s)(-1)][Correction added after online publication 16 Oct 2007: 30 mu mol changed to 20 mu mol] while in the vegetation sector it remained below 5 mu mol (m(2)s)(-1) and at summertime reached even -10 mu mol(m(2) s)(-1) [Correction added after online publication 16 Oct 2007: wording of sentence altered]. Effluxes from soil measured by chambers were 1-3 mu mol (m(2)s)(-1). F-c correlated with traffic density and a background non-vehicle flux was 1 mu mol (m(2)s)(-1) [Correction added after online publication 16 Oct 2007: 2 mu mol changed to 1 mu mol].

KW - 411 Agriculture and forestry

U2 - 10.1111/j.1600-0889.2007.00312.x

DO - 10.1111/j.1600-0889.2007.00312.x

M3 - Article

VL - 60

SP - 188

EP - 199

JO - Tellus. Series B: Chemical and Physical Meteorology

JF - Tellus. Series B: Chemical and Physical Meteorology

SN - 0280-6509

IS - 2

ER -