AIR-FLOW ACROSS AN ALPINE FOREST CLEARING - A MODEL AND FIELD-MEASUREMENTS

A steady-state two-dimensional model for neutrally stable turbulent flow inside and outside forest canopies is used to simulate the wind structure across an alpine forest clearing. The numerical method used is the pressure implicit splitting of operators (PISO) algorithm after Issa et al. Model results are compared with field measurements in the clearing and above the forest made with three-propeller Gill anemometers. The mean velocity errors of the model simulations in near-neutral conditions were approximately 10%. Individual 30-min run mean velocity errors varied from 0.2 to 30%.