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  • 1
    Electronic Resource
    Electronic Resource
    Comparison of surface meteorological measurements in TRACT database 4 (1996)
    Springer
    Annales geophysicae 14 (1996), S. 574-583 
    Details
    ISSN: 0992-7689
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The observational systems utilised during the TRACT experimental campaign (September 1992) can roughly be divided into: existing climate stations and towers: background chemical monitoring stations; aerological measurements; instrumented aircraft; and special micrometeorological stations operated only during the experimental period. Database 4, which contains the latter surface measurements, includes station descriptions and data from 21 sites operated by nine different groups during the campaign period. These data will be described briefly. There are a number of advantages in using a relational database for analysis of this data. Without creating an unnecessarily large database which is awkward to view and slow to process, specific measurements can be selected easily since data from each site have been standardized using a common time index. This allows comparison of the same or different variables from one or more sites for investigating data quality or the effects of site location. Data can readily be combined into hourly or daily averages or time series for comparison with other data sets (e.g. model or aircraft data). Spatial analysis is also straightforward, although the clustering of the sites in the centre of the investigation area means that care must be taken. Some preliminary comparisons are made here in order to demonstrate the availability and reliability of the data.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s00585-996-0574-9
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  • 2
    Electronic Resource
    Electronic Resource
    Respiration as the main determinant of carbon balance in European forests (2000)
    [s.l.] : Macmillian Magazines Ltd.
    Nature 404 (2000), S. 861-865 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Carbon exchange between the terrestrial biosphere and the atmosphere is one of the key processes that need to be assessed in the context of the Kyoto Protocol. Several studies suggest that the terrestrial biosphere is gaining carbon, but these estimates are obtained primarily by indirect ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/35009084
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  • 3
    Electronic Resource
    Electronic Resource
    Lateral coherence in isotropic turbulence and in the natural wind (1979)
    Springer
    Boundary layer meteorology 17 (1979), S. 353-373 
    Details
    ISSN: 1573-1472
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract A short review of experimental findings is given, followed by a theoretical derivation, based on Taylor's hypothesis, of formulas for lateral coherences. It is assumed that the flow is stationary and homogeneous. Explicit formulas are derived assuming an energy spectrum pertaining to the inertial subrange. Even when the last assumption is not fulfilled, there are only four different types of non-zero velocity coherences. These four coherences correspond to the combinations uu, vv, ww, and uv, where u, v, and w are the longitudinal, the transversal, and the vertical component of the turbulent velocity with respect to the direction of the horizontal mean wind velocity U. In the case of small displacements relative to the scale of turbulence, the coherences are shown to be universal functions of the non-dimensional frequency nD/¦U¦, where n is the frequency and D the lateral displacement. It is shown that these theoretical formulas for spectral coherences are in good agreement with atmospheric data. Finally, the role of the scale of the turbulence is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00117924
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  • 4
    Electronic Resource
    Electronic Resource
    The Askervein Hill Project: Vertical profiles of wind and turbulence (1988)
    Springer
    Boundary layer meteorology 43 (1988), S. 143-169 
    Details
    ISSN: 1573-1472
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract This is one of a series of papers on the Askervein Hill Project. It presents results from the Askervein 1982 and 1983 experiments in the form of vertical profiles of mean wind and turbulence integral statistics at upwind reference locations and at two hilltop sites. The data were obtained from a variety of sensors including sonic, Gill UVW and cup anemometers mounted on 50, 30, 17 and 10 m towers and TALA kite systems. Comparisons with numerical-model predictions are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00153977
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  • 5
    Electronic Resource
    Electronic Resource
    Turbulence and diffusion over inhomogeneous terrain (1987)
    Springer
    Boundary layer meteorology 41 (1987), S. 173-202 
    Details
    ISSN: 1573-1472
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract This paper provides an overview of some aspects of atmospheric boundary-layer dispersion processes over homogeneous and complex terrain. Special emphasis is placed on a discussion of the boundarylayer scaling regimes over homogeneous terrain and the characteristics of the dispersion processes associated with each of these regimes. The paper points out that vertical concentration profiles usually deviate substantially from a Gaussian distribution. The mean flow and turbulence over a low hill is dealt with, and in the inner layer the turbulence levels are increased due to the mean flow speed-up. In the outer layer the turbulence is modified by the rapid distortion effect. In a middle layer the turbulence is reduced due to the effect of a hill-induced streamline curvature. The paper concludes that the flow perturbations introduced by large-scale hills and valleys invalidate the use of simple approximations for describing atmospheric dispersion processes, and that it is necessary to utilize the full set of equations of motion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00120438
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  • 6
    Electronic Resource
    Electronic Resource
    Seasonal and diurnal variation in the deposition velocity of ozone over a spruce forest in Denmark (1995)
    Springer
    Water, air & soil pollution 85 (1995), S. 2223-2228 
    Details
    ISSN: 1573-2932
    Keywords: Ozone ; flux ; deposition velocity ; surface resistance ; canopy stomatal resistance ; water vapour flux ; Norway spruce
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The flux of O3 was measured by the eddy-correlation method over Norway spruce in periods when the trees had a very low activity, periods with optimum growth, and periods with water stress. The aerodynamic resistance (r a ), viscous sub-layer resistance (r b ) and surface resistance (r c ) to O3 were calculated from meteorological parameters and the deposition velocity. The canopy stomatal resistance to O3 was calculated from measurements of the water vapour flux. The deposition velocities showed a diurnal pattern with night-time values of 3.5 mm s−1 and day-time values of 7 mm s−1, when the trees had optimal growth conditions. The surface resistance was highly dominating in day-time and the influence of meteorology low. In night-time the surface resistance to 03 was lower than the canopy stomatal resistance. A low surface resistance was also found in winter-time, when the activity of the trees was low. The surface resistance increased when the trees were subject to water stress. It is concluded that stomatal uptake is an important parameter for the deposition of O3. However, other processes such as destruction of O3 at surfaces, reaction with NO emitted from the soil, and reactions with radicals produced from VOC's emitted from the forest, should also be taken into consideration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01186164
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  • 7
    Electronic Resource
    Electronic Resource
    Internal equilibrium layer growth over forest (2000)
    Springer
    Theoretical and applied climatology 66 (2000), S. 173-184 
    Details
    ISSN: 1434-4483
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Summary  Friction velocity data from different heights above a forest are used to evaluate the influence from the surrounding landscape on forest micro-meteorological measurements under near-neutral conditions. Data are used from one field site and two forest sites. The field site data are used to estimate the magnitude of the scatter. Different theoretical friction velocity profiles for the Internal Boundary Layer (IBL) are tested against the forest data. The results yield information on the Internal Equilibrium Layer (IEL) growth and an equation for the IEL height for neutral conditions is derived. For stable conditions the results indicate that very long fetches are required in order to measure parameters in equilibrium with the actual surface.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s007040070023
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