Papers Published

1. Fei Chen and Avissar, R., The impact of land-surface wetness heterogeneity on mesoscale heat fluxes, J. Appl. Meteorol. (USA), vol. 33 no. 11 (1994), pp. 1323 - 40 [1520-0450(1994)033<1323:TIOLSW>2.0.CO;2] .
   (last updated on 2007/03/27)

   Abstract:
   Vertical heat fluxes associated with mesoscale circulations generated by land-surface wetness discontinuities are often stronger than turbulent fluxes, especially in the upper part of the atmospheric planetary boundary layer. As a result, they contribute significantly to the subgrid-scale fluxes in large-scale atmospheric models. Yet they are not considered in these models. To provide some insights into the possible parameterization of these fluxes in large-scale models, a state-of-the-art mesoscale numerical model was used to investigate the relationships between mesoscale heat fluxes and atmospheric and land-surface characteristics that play a key role in the generation of mesoscale circulations. The distribution of land-surface wetness, the wavenumber and the wavelength of the land-surface discontinuities, and the large-scale wind speed have a significant impact on the mesoscale heat fluxes. Empirical functions were derived to characterize the relationships between mesoscale heat fluxes and the spatial distribution of land-surface wetness. The strongest mesoscale heat fluxes were obtained for a wavelength of forcing corresponding approximately to the local Rossby deformation radius. The mesoscale heat fluxes are weakened by large-scale background winds but remain significant even with moderate winds

   Keywords:
   atmospheric boundary layer;atmospheric movements;meteorology;