7.7
Spectral Transfer for Scalars and Velocity-Scalar Correlations in Inhomogeneous Turbulence for Atmosphere-Land Interaction
PAPER WITHDRAWN
Sukaran Ram Patel, Universidade Federal da Paraíba, Campina Grande, PB, Brazil
The Monin-Obukhov similarity theory is one of the most powerful tools in describing the physical properties of the atmospheric boundary layer. The Monin-Obukhov similarity empirical functions are now used routinely in many practical applications (Hill, 1989). Further, humidity and temperature measurements are not only intrinsically important as micrometeorological parameters but also, because they are the components of the electromagnetic index of refraction, they govern the propagation of waves in the clear turbulent atmosphere. Also, using optical scintillation measurements of inner scale and the refractive turbulence structure one may obtain complete micometeorological characteristics of the surface layer. The refractive index parameters is also considered as Monin-Obukhov quantity (Hill, 1989). There are several studies of similarity principles for horizontally homogeneous boundary layer, but very few for horizontally inhomogeneous surfaces because of their obvious difficulties. To avoid these problems most field experiments have been performed in carefully chosen homogeneous conditions. But in fact the atmosphere/land interface occurs in inhomogeneous surfaces. These motivate the study of various aspects of the spectral transfer of scalar (temperature, humidity, refractive index etc.) and scalar-velocity correlations in inhomogeneous turbulence in atmospheric boundary layer, as this is one of the several processes occurring in the turbulent motion. In this study, two point correlation equations for scalar correlation and velocity-scalar correlation are constructed. The terms associated with both turbulent self-interaction (Batchelor, 1953) and the mean gradients (Deissler, 1981) in the two-point spectral equation for homogeneous turbulence can be interpreted as transfer terms. However a similar interpretation does not seem obvious for inhomogeneous turbulence, because the condition of homogeneity is generally used in making the interpretation (Deissler, 1981). In this study, using the method of Deissler (1981), it is shown that certain terms in the two-point spectral equations for scalar and velocity-scalar correlations can be interpreted as spectral transfer terms even for general inhomogeneous turbulence. It is hoped that this study will help better understanding the modeling of the turbulent fluxes in land/atmosphere interface in the surface layer.
Session 7, Regional land-atmosphere interactions
Wednesday, 22 May 2002, 8:30 AM-11:30 AM
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