Climate Fact: Wind Speed Changes
In Brief: Higher elevation areas are experiencing the overall global trend of wind speed “stilling” more acutely than surrounding lowlands.
Wind speeds in the mid-latitudes have shown a downward trend over the past 30-50 years, a phenomenon known as “stilling.” Any trends in wind speed have implications for the water cycle, ecosystems and wind energy generation. Wind speeds pick up as the land-surface elevation increases. High elevation areas give birth to the river water that supports about 25 percent of the world’s gross domestic product, and climate changes at high elevations have potential implications for this water. In two high elevation areas, Switzerland and the Loess region of China, the overall trend in wind speed reduction has been more pronounced at higher elevations and during the winter months. For both of these study areas (which have similar climatologies) during the winter months, the wind speed increases by about 11 feet per second for every mile the land surface gains in elevation. Between 1960 and 2006, this wintertime rate of wind speed increase with elevation declined by about one percent. Wind speed is thus another climate variable that is changing faster at higher elevations.
Seasons: Winter, Spring
Source: McVicar, TR. “Observational evidence from two mountainous regions that near-surface wind speeds are declining more rapidly at higher elevations than lower elevations: 1960-2006.” Geophysical Research Letters 37 (2010): L06402.
