爆发性气旋研究的回顾

爆发性气旋又称“气象炸弹”,定义为在考虑地转调整到60°N时气旋中心气压加深率大于1 hPa/h的快速发展的气旋,具有中心气压急剧降低、强度急剧增大的特点,多发于洋面上,对海上航行安全及沿岸人民生产生活具有重要的影响。近几十年来,众多学者对爆发性气旋开展了广泛而深入的研究,在爆发性气旋的气候学特征、结构特征和发展机制等方面取得了较大的进展,但同时还有许多亟待解决的问题。本文结合前人对爆发性气旋的研究工作,系统地回顾和总结了爆发性气旋的研究进展,希望能够为将来对爆发性气旋的研究工作带来一些启发和思考。     

Interannual variability and predictability of summertime significant wave heights in the western north pacific

We propose and validate a linear regression model which enables us to predict the summer (June–August) mean of the monthly 90th percentile of significant wave heights (H₉₀) in the western North Pacific (WNP). The most prevailing interannual variability of H⁹⁰ is identified by applying an Empirical Orthogonal Function analysis to H⁹⁰ obtained from the ERA-40 wave reanalysis as well as from the optimally interpolated TOPEX/Poseidon (OITP) wave data. It is found that the increase of H⁹⁰ is correlated with cyclonic circulation in the WNP which links with warm SST anomalies in the Niño-3.4 region. We adopt zonal wind anomaly averaged over the region 5°N–15°N, 130°E–160°E (U^10N) as a predictor of the first principal component (PC1) of H⁹⁰, since U^10N is closely correlated with the PC1 of H⁹⁰. It is revealed that regression models obtained from two different wave datasets are nearly identical. The predictability of the regression model is assessed in terms of the reduction of the root-mean-square (rms) errors between H⁹⁰ and the reconstructed data. The predictor is found to be successful in reducing the rms errors by up to 40% for the ERA-40 wave reanalysis and by up to 70% for the OITP wave data within the latitudinal band 10°N–25°N, though rms errors exceeding 0.3 m still remain, particularly in the East China Sea.     

热带气旋风场的一种数值计算模式

利用动力学方程组，并对其中垂直梯度项和垂直扩散项进行了参数化处理。利用每日４次的地面天气图资料和台风年鉴中台风中心位置资料，采用数值计算方法对热带气旋及其环境场进行数值计算模拟。计算结果表明，用本模式得到的热带气旋风场及其周围的环境风场比利用公式法得到的风场更为合理。     

Importance of tropical cyclone heat potential for tropical cyclone intensity and intensification in the Western North Pacific

Which is more important for tropical cyclone (TC) intensity and intensification, sea surface temperature (SST) or tropical cyclone heat potential (TCHP)? Investigations using best-track TC central pressures, TRMM/TMI three-day mean SST data, and an estimated TCHP based on oceanic reanalysis data from 1998 to 2004, show that the central pressure is more closely related to TCHP accumulated from TC formation to its mature stages than to the accumulated SST and its duration. From an oceanic environmental viewpoint, a rapid deepening of TC central pressure occurs when TCHP is relatively high on a basin scale, while composite distributions of TCHP, vertical wind shear, lower tropospheric relative humidity, and wind speed occurring in cases of rapid intensification are different for each TC season. In order to explore the influence of TCHP on TC intensity and intensification, analyses using both oceanic reanalysis data and the results of numerical simulations based on an ocean general circulation model are performed for the cases of Typhoons Chaba (2004) and Songda (2004), which took similar tracks. The decrease in TCHP due to the passage of Chaba led to the suppression of Songda’s intensity at the mature stage, while Songda maintained its intensity for a relatively long time because induced near-inertial currents due to the passage of Chaba reproduced anticyclonic warm eddies appearing on the leftside of Chaba’s track before Songda passed by. This type of intensity-sustenance process caused by the passage of a preceding TC is often found in El Niño years. These results suggest that TCHP, but not SST, plays an important role in TC intensity and its intensification.     

造成我国北方暴雨的热带气旋天气学特征分析

本文利用１９６０～１９９４年台风年鉴资料，定义进入３０°Ｎ以北、１２５°Ｅ以西的热带气旋为影响北方热带气旋。根据定义普查，３５年中共有６３个造成北方暴雨，年均１．８个。我们把影响北方暴雨的６３个热带气旋根据后期移动路径的不同划分为６类，以５００ｈＰａ高空图为基础，分析西风带和副热带系统的特征，给出了各类热带气旋在影响北方前２４ｈ副热带和西风带系统的异同。     

一百多年来影响黄渤海热带气旋天气气候分析

本文对１８８４～１９９４年影响黄渤海的２３６个热带气旋进行了统计分析，给出其时空分布规律；将影响黄渤海的热带气旋分为五种类型，阐述了三种主要类型的路径特征、发展过程及产生的大风和降水天气分布。     

登陆珠江三角洲热带气旋暴雨的中尺度特征

利用逐时雨量分布图，对登陆珠江三角洲的热带气旋暴雨中尺度特征进行分类、对比和合成分析。实际资料证实了大范围的热带气旋暴雨是由若干中尺度雨团、雨带造成的，纯热带气旋环流形成的中尺度雨团、雨带具有与热带气旋云带大体一致的分布特征；有冷空气与之配合时，热带气旋环流北缘形成东西向的中尺度雨带；热带气旋登陆后的３ｈ可能出现最大中尺度雨团；随热带气旋环流的填塞减弱，中尺度而团也逐渐减弱消失；山地对中尺度雨团的移动起阻滞加强作用，有利的地形与暖湿气流配合，将激发生成新的中尺度雨带。     

西北太平洋热带气旋中期路径的统计释用综合预报模式

提出一个热带气旋中期路径的统计释用综合预报模式。该模式应用ＴＣ参数，初妈时刻及未来时刻的环境场参数和导出因子，构造了多种中期天气时空惊讶的预报因子；应用数值天气预报产品的统计释用技术和多种分类预报模式的综合集成，构造了ＴＣ中期路径的客观定量预报模式。     

南海海区热带气旋移速突变的分析

应用天气学与动力学相结合的方法,分析发现:鞍型场、西风槽和双热带气旋形势是热带气旋移速突变的环流背景。在上述环流背景的条件下,涡度、涡度平流、流函数、850—200hPa垂直切变以及不对称配置的演变与热带气旋移速突变有超前相关;概括出的一些判据可供业务实践参考。     

厦门地区热带气旋分析

根据1952～1990年实测热带气旋资料,对影响(包括登陆)厦门的184次热带气旋进行了气候分析,并引进均生函数的概念,采用改进后的正交筛选方法,探索了热带气旋活动周期,得出本地区热带气旋约80%(其中登陆的90%)出现于夏季(7～9月),11、6、12、5a等周期振荡较显著等结论。