Characteristics of turbulence in the atmospheric surface layer over a complex terrain

Abstract

<span style="mso-bidi-language:HI">Measurements of fluctuating wind components and temperature have been made in the atmospheric surface layer over a complex terrain in the campus of the Indian Institute of Tropical Meteorology, Pune, using sonic anemorneter at 5.2 m above the surface. Characteristics of turbulence, i.e. spectra of wind velocity components and turbulence statistics of wind are presented. The peak of normalized <i>w</i>-spectrum over a complex terrain for near-neutral condition was found to be ~ 0.6 as compared to ~ 0.4 over homogeneous terrain. The non-dimensional frequency maximum for <i>w</i>-component spectrum was observed to be 0.9 as compared to ~ 0.5 over homogeneous terrain. Empirical formulae for standard deviation of velocity components have been tested against observations over hilly terrain. Vertical flux of turbulence kinetic energy as a function of stability is also discussed.

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