Papers Published

1. Avissar, R. and Schmidt, T., An evaluation of the scale at which ground-surface heat flux patchiness affects the convective boundary layer using large-eddy simulations, J. Atmos. Sci. (USA), vol. 55 no. 16 (1998), pp. 2666 - 89 [1520-0469(1998)055<2666:AEOTSA>2.0.CO;2] .
   (last updated on 2007/03/27)

   Abstract:
   The effects on the convective boundary layer (CBL) of surface heterogeneities produced by surface sensible heat flux waves with different means, amplitudes, and wavelengths were investigated. The major objective of this study was to evaluate at which scale surface heterogeneity starts to significantly affect the heat fluxes in the CBL. The large-eddy simulation option of the Regional Atmospheric Modeling System (RAMS-LES) developed at Colorado State University was used for that purpose. Avissar et al. evaluated this model against observations and demonstrated its reliability. It appears that the impact of amplitude and wavelength of a heat wave is nonlinearly dependent upon the mean heating rate. It can be concluded that as long as the “patchiness” of the landscape has a characteristic length scale smaller than about 5-10 km (even without background wind), the “mosaic of tiles” type of land surface scheme suggested by Avissar and Pielke can be applied to represent the land surface in atmospheric models. At larger scales, the impact of landscape heterogeneity may be significant, especially when the atmosphere is humid

   Keywords:
   atmospheric boundary layer;atmospheric thermodynamics;heat transfer;