西北太平洋热带气旋尺度的气候特征研究

使用美国联合台风警报中心（Joint Typhoon Warning Center，简称JTWC）整编的2001-2006年的热带气旋（简称TC）资料，分析了TC尺度季节变化特征、区域分布情况，并讨论了TC尺度和强度的关系，初步探讨了西北太平洋热带气旋尺度的气候特征。研究结果表明：TC尺度有明显的季节变化特征，平均尺度在4月份最大，达到230．4km，2月份最小，为69．5km；TC尺度有明显的区域分布不均匀性，TC尺度出现最大值的区域位于28．6～29．5°N，131．1～133．0°E的海面上，而在123°E以东和12°N以南地区，TC尺度往往都在200km以下；对于不同强度的TC，其尺度与强度变幅有明显差异，热带风暴（TS）的24h尺度变幅最大，而台风（TY）的24h强度变幅最大；TC尺度和强度的相关性在不同路径下是有差异的，西北行、西行、北上型的TC尺度与强度呈显著的正相关，两者的相关系数达到了0．93以上，东北行和回旋型的TC尺度和强度的相关系数接近0．6，转向型TC的相关系数在0．85左右；此外，TC尺度和强度的相关性在其生命史的不同阶段也存在显著差异，在发展期，尺度和强度的相关性最好，其相关系数达到0．92，其他阶段相关性则减弱．

Climatic Characteristics of the Western Pacific Tropical Cyclone Size

Based on the data of the tropical cyclone （2001--2006） from the Joint Typhoon Warning Center （JTWC）, the climatic characteristics of the Western Pacific tropical cyclone （TC） size are preliminary discussed. The analyses include the seasonal variation and the regional distribution for TC size, and the relationship between TC size and TC strength. The results are shown： TC size has distinct seasonal variation, with the maximum average size reaches 230.4km in April, while the minimum 69.5km in February. TC size has obvious regional distribution inhomogeneity, with the maximum located in the 28.6 - 29.5°N, 131.1 - 133.0°E area, while in the east area of 123°E and in the south area of 12°N always under 200km. For different strengths, the change ranges for the TC size and TC strength are very different： the tropical storm （TS） has the maximum size change in 24h while the typhoon （TY） has the maximum strength change. In different paths, the correlations of TC size and TC strength are various： for the Northwest, Westward and Northward TC, the TC size has significant positive correlation with the TC strength, with the correlation coefficient above 0.93; for the Northeast and cyclotron TC, the correlation coefficient is close to 0.6; and for the turning TC about 0.85. In addition, in different stages of life history, the correlations of TC size and TC strength have obviously difference： with the best correlation coefficient of 0.92 in the development period, and weakened in the other periods.