Abstract:
Based on the nocturnal high-altitude radiosonde observation data collected in the coastal area of Fuzhou from 2018 to 2020, the occurrence patterns and characteristic parameters of surface ducts and elevated ducts in different seasons were statistically analyzed. The results indicate that atmospheric ducts in the coastal area of Fuzhou mainly occur from May to November each year. The probability of occurrence of atmospheric ducts at night in summer is about 70% (except for June), and about 50% in winter. Affected by the rainy season, the probability of occurrence of atmospheric ducts in June is significantly lower than that in other summer months, at about 50%. In addition, the number of elevated ducts observed far exceeded that of surface ducts, with elevated ducts accounting for approximately 94.8% of the total duct layers and surface ducts comprising only about 4.2%. Surface ducts mainly occur at height levels below 100m, with relatively weak overall intensity, and the occurrence frequency in summer is significantly higher than that in winter. Elevated ducts are mainly weak ducts, and strong ducts mainly occur in summer and autumn. The proportions of elevated ducts occurring at altitudes of
1000–
4000 m, with thicknesses of less than 100 m, and with strengths below 10 M-units were approximately 79%, 65%, and 87.5%, respectively. The statistical results can provide support for research on the environmental characteristics of atmospheric ducts along the southeast coast of China.