High-resolution observations of the near-surface wind field over an isolated mountain and in a steep river canyon

摘要: Abstract. A number of numerical wind flow models have been developed for simulating at relatively fine spatial resolutions (e.g., ~ 100 m); however, there are very limited observational data available evaluating these high-resolution models. This study presents surface sets collected from an isolated mountain and a steep river canyon. The presented in terms four regimes: upslope, afternoon, downslope, synoptically driven regime. There were notable differences the two terrain types. For example, speeds on increased with distance upslope during flow, but generally decreased canyon site flow. In downslope speed did not consistent trend position mountain, site. highest measured occurred passage frontal systems mountain. Mountaintop winds often twice as high surrounding plain. late morning hours easterly down-canyon flows, presumably associated pressure gradients induced by formation regional thermal trough to west east. Under periods weak synoptic forcing, tended be decoupled large-scale under strong variability was sufficiently large due terrain-induced mechanical effects (speed-up over ridges leeward sides obstacles) that mean would representative most locations or within feature. These findings suggest traditional operational weather model (i.e., grid around 4 km larger) predictions likely good predictors local near-surface sub-grid scales complex terrain. Measurement can found http://www.firemodels.org/index.php/windninja-introduction/windninja-publications .