利用1979-2012年美国National Oceanic and Atmospheric Administration （NOAA）的Climate Prediction Center （CPC）海温和陆地雪盖资料、美国国家冰雪研究中心（NSIDC）的两极海冰资料,使用相关分析等方法研究影响广西热带气旋频数的气候预测模型.研究结果表明：从气候变化来看,影响广西热带气旋数量在50年代～70年代前期为偏多期,70年代中期～90年代中期为正常期,90年代后期～10年代为偏少期,历年变化呈显著的减少趋势.与各个影响因子相关来看,影响广西热带气旋数量与海温同步关系比较好,而随时间间隔越长相关越差,其中与同年赤道太平洋海温指数大部为反相关,与全球海温相关最显著的区域为日本和格陵兰岛的以南洋面.影响广西热带气旋数量与两极海冰的相关不显著,而与前一年1月北美雪盖的相关显著.通过逐步回归建立影响广西热带气旋气候预测模型,预测效果良好.
Based on the daily precipitation data of 83 stations in Guangxi and the NCEP/NCAR monthly reanalysis data from 1979 through 2008, the characteristics of spatial and temporal distribution and variation of the rainstorm concentration degree(RCD) and the rainstorm concentration period(RCP) are analyzed by using the methods of Monte Carlo test etc. The results are shown as follows. The rainstorm events are concentrated in April-September, taking up about 90% of the yearly rainfall total, and the percentages of rainstorms in the annual total precipitation have an increasing tendency. RCD in the east of Guangxi is larger than that in the west. The RCP in the northeast and southwest of Guangxi is later than that in the other regions, and has the earliest onset in the northern mountainous regions of Baise and southeast Guangxi. The RCD exhibits an increasing tendency in the northwest and the coastal region while showing a decreasing tendency in the other regions. On a long-term basis, the RCP in the east and coastal region has a postponing trend but tends to be earlier in the other regions. The proposed mechanism is as follows: If the geopotential height in the south of Qinghai-Tibet Plateau and the West Pacific has a highly negative anomaly in winter, the western Pacific subtropical high will be strong in summer, which increases the RCD in Guangxi. If the geopotential height has a highly positive anomaly in winter, the subtropical high will have a significant periodic oscillation in summer, which decreases the RCD in Guangxi. The value of RCD is high(low) in the area of northern mountainous regions of Guangxi and Beihai in strong(weak) South China Sea summer monsoon years, while in the other areas, the value of RCD is low(high).
