Field measurement study on classification for mixed intense wind climate in mountainous terrain

The wind in mountainous terrain is a mixed system, including large-scale synoptic wind and local-scale periodic thermally-driven wind. Placing all kinds of intense winds into one group may misestimate the mountain wind field's extreme wind speed and wind parameters. So, there is an urgent demand for classifying intense winds into homogenous groups. For this reason, a classification framework and extraction program for intense winds in mountain terrain according to their wind speed and temperature features is undertaken. A series of local-scale periodic thermally-driven winds, sudden intense winds, and large-scale cooling windstorms are identified and extracted from the long-term field measurements in a mountain area. Further, the mean and fluctuating characteristics of various intense winds are compared. The time–frequency changes of turbulent kinetic energy in several typical strong wind processes are studied through the evolutionary power spectrum. Remarkable differences are founded in wind parameters for intense winds with different scales.