Urbanization is only moderately responsible for changes in surface wind speed in northwest China, a recent study by Chinese scientists has found.
The study, based on data from 68 stations in northwest China from 1969 to 2015, found that changes in surface wind speed are caused by thermal differences in this area.
"Thermal differences are related to variations in the surface pressure gradient caused by the changed surface temperature gradient," said CHEN Yaning, scientist from Xinjiang Institute of Ecology and Geography (XIEG) of the Chinese Academy of Sciences, who led the study.
The reduction in surface wind speed is harmful to human and animal comfort and the environment at large.
Surface wind speed in northwest China declined from 1969 to 2015, with the year of 1992 as a clear turning point. The wind speed downward trend reversed to an upward one in 1992, according to the study.
Surface wind speed in northwest China is affected by changes both in large-scale atmospheric circulation and in regional warming, said CHEN. Surface pressure gradient variations between high- and low-latitude regions may be important contributors to wind speed changes under asymmetric warming.
"Neither urbanization nor changes in observation instruments are the main reasons for changes in surface wind speed in northwest China," CHEN said.