Papers Published

1. Katul, Gabriel G. and Mahrt, Larry and Poggi, Davide and Sanz, Christophe, One- and two-equation models for canopy turbulence, Boundary-Layer Meteorology, vol. 113 no. 1 (2004), pp. 81 - 109 [e5] .
   (last updated on 2007/04/09)

   Abstract:
   The predictive skills of single- and two-equation (or K-ε) models to compute profiles of mean velocity (U), turbulent kinetic energy (K), and Reynolds stresses (u prime w prime ) are compared against datasets collected in eight vegetation types and in a flume experiment. These datasets range in canopy height h from 0.12 to 23 m, and range in leaf area index (LAI) from 2 to 10m² m^-2. We found that for all datasets and for both closure models, measured and modelled U, K, and (u prime w prime ) agree well when the mixing length (lm) is a priori specified. In fact, the root-mean squared error between measured and modelled U, K, and (u prime w prime ) is no worse than published values for second- and third-order closure approaches. Within the context of one-dimensional modelling, there is no clear advantage to including a turbulent kinetic dissipation (ε) budget when lm can be specified instead. The broader implication is that the added complexity introduced by the e budget in K-ε models need not translate into improved predictive skills of U, K, and (u prime w prime ) profiles when compared to single-equation models. © 2004 Kluwer Academic Publishers.

   Keywords:
   Reynolds number;Kinetic energy;Vegetation;Stresses;Energy dissipation;Computational complexity;Mathematical models;