利用风廓线雷达资料分析哈尔滨机场低空急流特征

Study on the Characteristics of Low-Level Jets at Harbin Airport Based on Wind Profiler Data

利用2019—2021年哈尔滨太平国际机场风廓线雷达资料和观测月总薄、年总薄资料,从低空急流月变化、日变化、风向、持续时间、中心速度、中心高度及其和降水的关系几个方面对低空急流的特征进行统计分析。结果表明:哈尔滨机场的低空急流有明显的季节性变化特征,春、秋季出现的概率明显高于夏、冬季;在一天中的任何时刻均可发生,其出现时间的日变化特征是在早晨到上午出现的次数最多,从午后开始逐渐减少,到午夜次数达到最低,此后次数又逐渐增多;以西南急流为主,从低空急流持续时间变化来看,持续时间为7~12 h的天数最多,持续时间大于18 h的次之,持续时间为4~6 h的天数最少;中心高度主要集中在0~500 m,中心速度集中在20 m/s;降水与低空急流有密切关系,除此之外,还和逆温层的存在有关;低空急流中心最大速度和单日最大降水量显著相关,低空急流中心速度的增大可能导致单日最大降水量的增多。

Using the wind profiler data and the monthly and annual observation information at Harbin Taiping International Airport from 2019 to 2021,the characteristics of low-level jets were statistically analyzed from the aspects of monthly changes,diurnal changes,wind direction,duration,center speed,center height,and the relationship with precipitation.The results show that the low-level jets at Harbin Airport have obvious seasonal variation characteristics,and the probability of occurrence in spring and autumn is significantly higher than that in summer and winter.Low level jets can occur at any time of the day.The daily change of the occurrence time is characterized by the largest number of occurrences from early morning till noon,gradually decreasing from noon,reaching the lowest level at midnight,and increasing again from then on.For the wind direction,the low level jets are dominated by southwest jets.From the perspective of the jet duration,the highest number of days are accompanied with the jet duration of 7~12 h,followed by the jet duration longer than 18 h,and the lowest number of days are associated with the jet duration of 4~6 h.The center height of the low level jets mainly ranges from 0~500 m and the center wind speed hovers around 20 m/s.Precipitation is closely related to low level jets.Moreover,it is linked with the inversion layer.Significant correlation is identified between the maximum center speed of the low level jets and the maximum precipitation in a single day.The strengthening of the center speed of the low level jets may lead to the enhanced maximum precipitation in a single day.