| 摘要: |
| 建立南海海域1949～2007年6～10月份热带气旋(以下简称TC)年、月频数和TC中心强度的历史资料统计文件, 分析TC的年月变化。结果表明: 近50年, TC具有10 a左右的周期变化, 1964～1974年和1985～1995年为南海两个强台风以上级别频发期, 1997～2006年为TC频数少且强度弱的时期。同时TC强度的空间分布分析结果表明, 中沙北部海域和东沙西部海域为强台风多发生区, 各月TC强度分布特征明显不同, 且其加强通道具有南-北-南阶段性变化。另外, 通过分别对1949～2007年北半球500 hPa高度场及海温场的格点资料和TC强度历史资料的相关计算, 选取高相关格点, 根据相关权重组成组合因子, 构建二次型预测方程, 做年月TC强度预测。预测检验结果显示, 冬季的高度场和海温场对次年的TC强度预测效果良好。 |
| 关键词: 南海热带气旋 气候变化 强度预测及检验 |
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| 基金项目:2008 年中国气象局业务建设项目(热带气旋气候预测业务系统) |
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| A study on the climate characteristics and the intensity prediction of the tropical cyclones affected in the South China Sea |
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| Abstract: |
| Based on the frequency and intensities of the tropical cyclones (TCs) affected the South China Sea(SCS) from June to October in 1949～2007, the climatic characteristics and the secular variation trend were analyzed. The result shows the TCs affected SCS have a quasi-decadal oscillation in recent 50 years and there are two kinds of variation periods, one is the frequently-occurring stage of strong typhoon during 1964～1974 and 1985～1995, the other is a low occurring frequency and weak intensity stage during 1997～2005. By the spatial analysis, two intensified significant areas were found out to be the area north to Zhongsha and the area east to Dongsha. The monthly intensity of the TCs has an obviously different spatial distributions and seasonal variations of the intensified channel.
The correlation coefficients between the monthly mean geopotential height in Northern Hemisphere of 500 hPa, the monthly mean SST of the North Pacific Ocean, and the intensity of the TCs affected in SCS (1949～2007) were calculated. By analyzing the statistical characteristics of those highly significant regions, several high correlated factors were selected and combined to construct the binomial equations. This prediction model has a high fitting ability and performs well in the operation. |
| Key words: tropical cyclone affecting the South China Sea climate change intensity prediction and verification |
