Abstract:
Based on the Ka-band cloud radar observation data of Liupan mountain meteorological station from September of 2017 to August of 2018, the occurrence frequency and macro characteristics of different clouds at the top of the Liupan mountain were analyzed.The results show that the highest occurrence frequency of Liupan mountain cloud i.e.61% appears in July, and the lowest value i.e.26% appears in December.Divided by the number of clouds, the clouds at the top of Liupan mountain are mainly one layer of cloud, two layers of clouds and three layers of clouds, their monthly average occurrence frequencies relative to total clouds are 68%-86%, 14%-27% and 0.4%-4.8%, respectively.Divided by cloud bottom height and cloud thickness, the ratios of monthly average occurrence frequencies of the low, medium, and high clouds and straight cloud to the total cloud are 29%-53%, 14%-58%, 6%-22%, and 2%-20%, respectively.The height of the cloud base is higher in winter and spring than in summer and autumn.The height of cloud top is higher in summer and autumn than in winter and spring.The thickness of clouds is between 1.6 km and 3.6 km and its annual variation characteristics are similar to that of the cloud top height.On the whole, the thicknesses of clouds in spring, summer, and autumn are larger in the daytime than in nighttime, while the thickness of clouds in winter is larger in nighttime than in the daytime.Besides, the cloud thicknesses in summer and autumn both indicate obvious diurnal variation characteristics.