Abstract:Based on the 1953-2010 meteorological records at the Nanyue Mountain Observatory, the climatic variations of winds are examined by using the trend analysis, the vector decomposition, the wavelet analysis, and the Mann Kendall test statistics. The results can be shown that: (1) the prevailing winds over the Nanyue Mountain exhibit significant seasonal variations, with the prevailing wind being southwesterly in spring and summer and being northerly in autumn and winter; (2) annual mean wind speed experienced statistically significant decreasing at an averaged rate of -0.25 m·s-1/decade, with the maximum trend occurring in summer and minimum trend in winter. In addition, vector decomposition analysis indicates that both meridional and zonal wind speeds show decreasing trends, with the meridional declining faster than the zonal declining. For the meridional slowdown, the north wind decrease is faster than the south wind. Statistically significant declining trends in the west and south wind components can only be detected in summer, while significant slowdown in the north wind can be found in all seasons except in summer. Analysis also indicates that winds over the Nanyue Mountain exhibit significant interannual and interdacedal variations. Oscillations with 16 year periods can be detected both in annual mean and winter wind speeds, but they are remarkably changed after the 1990s. It is suggested that the interdecadal variation of wind speed may be closely associated with the variations of large scale East Asian monsoon systems.