Mesoscale Wind Climate Modelling in Steep Mountains

• Main Authors: Jean-paul Pinard, Robert Benoit, John D. Wilson
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2008
• Subjects: Yukon; Whitehorse
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.573.270; http://www.esc.gov.yk.ca/pdf/pinard_benoit_wilson2009(1).pdf

ABSTRACT Although the Mesoscale Community Compressible (MC2) model successfully reproduces the wind climate (for wind energy development purposes) of the Gaspé region, equivalent simulations for the steep moun-tainous southern Yukon have been unsatisfactory. An important part of the problem lies in the provision of suit-able boundary conditions in the lower troposphere. This paper will describe an alternative provision of boundary conditions to the MC2 model based partly on standard National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) Reanalysis statistics, however, with modified lower tropos-pheric conditions based on local radiosonde measurements. The MC2 model is part of the AnemoScope wind energy simulation toolkit which applies statistical-dynamical downscaling of basic large-scale weather situations (i.e., the NCEP/NCAR Reanalysis) to simulate the steady-state wind climate of a complex region. A case study summarized here imposes a typical mean winter tempera-ture inversion on the boundary conditions to reduce downward momentum transfer in the MC2 model over the Whitehorse region. In conjunction with this step, the geostrophic wind at the boundaries is held constant (with height) in speed and direction, based on the (observed) dominant southwesterly winds above the mountaintops. The resulting simulation produces wind directions within the modelled domain that are in much better agreement with the available measurements. However, despite the imposed atmospheric stability, downward transfer of hor-