天津沿海地区测风塔不同高度风速特征

Characteristics of wind speed at different heights of wind mast in Tianjin coastal areas

利用天津市东部沿海地区汉沽、大港测风塔2017-2019年观测数据,统计分析了测风塔不同高度风速的时间变化特征,对30~100 m风速与10 m风速的关系以及风切变指数的变化规律进行了探讨。结果表明:各个高度上风速均具有明显的季节变化特征,春季风速最大,且最易出现大风天气,平均风速、大风日数及大风强度均达到最高;夏秋季转换期风速最小。风速具有明显的日变化特征,午后各个高度的风速均达到最大值。相关分析表明,30~100 m风速与10 m风速表现出显著的正相关关系。各高度与10 m高度的风速之差、风切变指数呈现出相似的日变化特征,即午后海风盛行阶段两者均最小。此外,通过对比两个测风塔风速的变化特征发现,汉沽平均风速更大,大风天气发生频次更多,强度更强,且风速的日变化和海陆风变化特征更加明显。

Based on the observation data from wind masts in Hangu and Dagang at the eastern coastal area of Tianjin from 2017 to 2019,the temporal variation characteristics of wind speed at different heights of wind masts were analyzed statistically,and the relationship between wind speed at 30~100 m and 10 m as well as the variation of wind shear index,were discussed.The results showed that the wind speed at each height had obvious seasonal variation characteristics.In spring,the wind speed was the highest,and the most prone to gales.The average wind speed,the number of gales days,and the intensity of gales were the highest.The wind speed was minimum during the transition period of summer and autumn.In addition,the wind speed had obvious diurnal variation characteristics,and the wind speed at each height reached the maximum in the afternoon.Correlation analysis showed that the wind speed at 30~100 m was positively correlated with that at 10 m.The difference in wind speed and wind shear index at each height and 10 m height showed similar diurnal variation characteristics,that is,they were both minima in the afternoon when sea breeze prevail.Comparing the characteristics of two wind masts,it was found that the mean wind speed in Hangu was larger,the frequency of gale weather was more frequent,the intensity of gale was more,and the diurnal variation of wind speed and sea and land wind was more obvious.