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Gabriel Katul

Publications [#58561] of Gabriel Katul

Papers Published

  1. Detto, M. and Katul, G.G., Simplified expressions for adjusting higher-order turbulent statistics obtained from open path gas analyzers, Boundary-Layer Meteorology, vol. 122 no. 1 (2007), pp. 205 - 216 [s10546-006-9105-1] .
    (last updated on 2007/04/25)

    Abstract:
    When density fluctuations of scalars such as CO2 are measured with open-path gas analyzers, the measured vertical turbulent flux must be adjusted to take into account fluctuations induced by 'external effects' such as temperature and water vapour. These adjustments are needed to separate the effects of surface fluxes responsible for 'natural' fluctuations in CO2 concentration from these external effects. Analogous to vertical fluxes, simplified expressions for separating the 'external effects' from higher-order scalar density turbulence statistics are derived. The level of complexity in terms of input to these expressions are analogous to that of the Webb - Pearman - Leuning (WPL), and are shown to be consistent with the conservation of dry air. It is demonstrated that both higher-order turbulent moments such as the scalar variances, the mixed velocity-scalar covariances, and the two-scalar covariance require significant adjustments due to 'external effects'. The impact of these adjustments on the turbulent CO2 spectra, probability density function, and dimensionless similarity functions derived from flux-variance relationships are also discussed. © Springer Science+Business Media B.V. 2006.

    Keywords:
    Carbon dioxide;Density of gases;Probability density function;Turbulent flow;

    



 

Contact Katul at:

A318 LSRC
Box 90328
Durham, NC 27708
919-613-8033
fax: 919-684-8741
gaby@duke.edu