Changes of the probabilities in different ranges of near-surface wind speed in China during the period for 1970-2011

Slowdown in near-surface wind speed (SWS) has been revealed over China in the last 30 years, but changes of probabilities in different wind ranges and probability distribution of SWS are still not involved. In this paper, the changes of probabilities in different wind ranges and probability distribution of SWS from 1970 to 2011 were studied. The results show: (1) The annual mean SWS declined at a rate of −0.15 m s−1 decade−1, meanwhile, the monthly mean variation of probabilities for six wind ranges showed a bimodal fluctuation. (2) The long-term trends of probabilities of 0.3-1.5 m s−1 and 1.6-3.3 m s−1 increased, while the probabilities of 3.4-5.4 m s−1, 5.5-7.9 m s−1, and ≥8.0 m s−1 declined over the 42-year period. (3) The probability of SWS beyond 3.0 m s−1 was lower in large city than that in small city, meanwhile, the probability density function curves in similar sized city in different climate zones were not consistent, which implied that the probability distribution of SWS could be affected by both urbanization and climate characteristics.