影响山东的热带气旋年际和年代际变化

The Inter-annual and Inter-decadal Variation of Tropical Cyclone Affecting Shandong Province

利用1949—2006年热带气旋年鉴资料对58年来影响山东的热带气旋频数和强度,以及热带气旋引起的暴雨和大风进行了气候统计学分析。分析表明:7月下旬至8月下旬是热带气旋影响山东的主要时段。影响山东的热带气旋具有明显的年代际变化,并存在显著的2.4年和5年左右的周期变化,但影响山东的热带气旋强度呈明显减弱趋势,年代际变化不明显;8月份影响山东的热带气旋最多,极易发生洪涝和强风灾害,所造成的暴雨和大风的次数与热带气旋频数的变化较为一致。通过分析影响山东热带气旋活动与太平洋海温和西太平洋副高的关系,指出,北太平洋海温关键区以及西太平洋副高的气候变化对热带气旋活动有着很重要的作用。

Based on tropical cyclone yearbook data from 1949 to 2003, the climate characteristics, such as inter-decadal variation, period of tropical cyclone＇s frequency, rainstorm and strong wind, intensity characteristics, are analyzed. Main results are as follows： Tropical cyclone affect- ing Shandong Province is from the last ten-day of July to August and its inter-decadal variation obeys the Student＇s t-test; The marked periodic variation of every 2.4 years and 5 years is found according to power spectrum analysis. It shows obvious weakening tendency about tropical cyclone＇s intensity by using Kendall test. It also shows that August is the strongest month in a year for rainstorm frequency and intensity, and flood disaster is more easily occurred during this month. It is distinct for frequency＇s inter-decadal variation of tropical cyclone causing rainstorm and strong wind. Marked period exists about annual average precipitation and strong wind. At the same time, the cause of the variation is discussed.