Mountain winds

USA Rocky Mountain Wind River subbituminous and bituminous 41 samples 0.43-40 U.S. Geological Survey Coal Quality Database (2006)... 

Winds were studied in the Carbon River Valley near Mount Rainier (5). The longitudinal sectional winds are shown in Figure 5 a and b. The down-valley or mountain wind persisted until midafternoon on 9 and 10 August. The up-valley or valley winds started at the base of the valley at 1200 on 10 August and increased in thickness during the afternoon. Above these valley winds were anti-valley and anti-mountain winds which varied in direction from the lower winds by 90 to 180 degrees. 

Figure 5. Mountain and valley winds in the Carbon River Valley near -vicinity of Mount Rainier, Washington. Local down valley direction AV, antivalley wind AM, antimountain wind M, mountain wind V, valley wind. (Reproduced with permission from Ref. 5. Copyright 1966, Springer Verlag.)...

Data for one full year (1964) for Nashville, Tennessee, and Knoxville, Tennessee, 265 km (165 mi) apart, were compared to determine the extent to which the frequencies of various parameters were similar. Knoxville is located in an area with mountainous ridges oriented southwest-northeast Nashville is situated in a comparahvely flat area. The data available are the number of hours during which each of 36 wind directions (every 10° azimuth) occurred, the average wind speed for each direction, the number of hours of each Pasquill stability class for each direchon, and the mean annual wind speed. 

Conditions are frequently suitable for the formation of lee waves over the mountainous regions of the US, an effect that is routinely exploited by glider pilots to obtain exceptionally high altitudes. The combination of lee waves with strong winds that are sufficient to produce damage to structures is fortunately rare, but do occur in hazardous mountainous regions. 

The origin of atmospheric turbulence is diurnal heating of the Earth s surface, which gives rise to the convection currents that ultimately drive weather. Differential velocities caused perhaps when the wind encounters an obstacle such as a mountain, result in turbulent flow. The strength of the turbulence depends on a number of factors, including geography it is noted that the best observation sites tend to be the most windward mountaintops of a range— downwind sites experience more severe turbulence caused by the disturbance of those mountains upwind. 

Another challenge is selecting an appropriate location for the turbine, due to the highly localized nature of wind. Low-cost anemometers may help alleviate this problem, but time must be spent to collect a sufficient amount of data [10]. Areas particularly suited to wind power because of their typical high wind velocities include coastlines, high ground, and mountain passes [12]. Wind power does not need water, so it is suitable for dry areas. 

The province s climate is defined as subtropical mountainous with a dry season. However, the topography does allow the development of contrasting environments. Thus, the moist winds from the southeast enter the province and release their moisture from submountainous ranges... 

Grubb and Meyer (1993) estimate the technical wind potential for Western Europe to be 17 280PJ/year, corresponding to 15% of the gross electric or theoretical potential (113 040 PJ/year). They exclude areas unsuitable for wind energy production, such as cities, forests and inaccessible mountains, as well as social, environmental and land-use constraints from the theoretical potential and estimate the technical potential. Only sites with an average wind speed above 6 m/s are included, assuming an efficiency factor of 0.3. 

One significant feature of mountain ranges is their barrier effects which can block or alter entire wind systems, the consequences of which can be observed not only in the mountains themselves but also much further afield. As a natural barrier, the Alps trigger convective and advective cloud formation, particularly in their peripheral areas. Hence they exhibit much more humid conditions than their adjacent environment [3]. As regards the small-scale distribution of precipitation in the mountains themselves, the differences between windward and leeward in... 

When humid, warm air masses are transported towards a chain of mountains by the prevailing wind systems, they are forced upwards and simultaneously cooled by the natural barrier. If, in the process, the temperature reaches or falls below dew point, clouds are formed on the windward side of the mountain range. The intensity of the precipitation triggered by this process exhibits a high spatial variability, with precipitation rates primarily dependent on the uplift distance, uplift velocity and... 

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