西北太平洋热带气旋路径时间标度律的研究     

肖天贵 《南京气象学院学报》1995,18(3):444-449

时间标度计算表明，西北太平洋热带气旋路径是一个无标度性的系统，其关联方差谱遵从频率的－２￣－３次方幂律，不同背景下的路径系统均如此。由此得到的不同季节、不同地域的热带气旋路径可预报时间尺度基本上为３￣４ｄ，但异常热带气旋路径的可预报时间尺度则为１￣２ｄ。  相似文献   

近百年西北太平洋热带气旋年频数的变化特征   总被引：7，自引：5，他引：7  

张光智  张先恭  魏凤英 《热带气象学报》1995,11(4):315-323

利用经趋势订正的１８８４－１９８８年西北太平洋热带气旋年频数资料，分析了热带气旋年频数的多年变化及其与海面温度、南方涛动指数、太阳黑子数和环流型日数等的统计关系。初步结果表明，热带气旋年频数的变化具有明显的２１年、３１年、１５年和６年左右的周期和持续期平均为１２年左右的阶段变化；近百年来有三次较明显的转折，分别出现在１９３１、１９５９年１９７７年。热带气旋年频数在厄尔尼诺年有冬春季偏少、夏秋季偏多  相似文献   

VENTILATION FLOW IN A BAROCLINIC VORTEX RELATED TO TROPICAL CYCLONE MOTION^*          下载免费PDF全文

Tian Yongxiang 《Acta Meteorologica Sinica》1995,9(3):338-348

The tropical cyclone motion is numerically simulated with a quasi-geostrophic baroclinic model.The flow field of a tropical cyclone is decomposed into its axisymmetric and asymmetric components.The relation between the ventilation flow vector and the motion vector of the tropical cyclone is investigated.The results of numerical experiments indicate:(1) There are both large-scale beta gyres and small-scale gyres in the asyrnmetric flow field.(2) The interaction between small-scale gyres and large-scale beta gyres leads to the oscillation of translation speed and translation direction for the tropical cyclone.(3) There are the large deviations between the ventilation flow vector calculated by means of Fiorino and Elsberry's method and the motion vector of tropical cyclone.(4) The ventilation flow vector computed using the improved method closely correlates with the motion vector of the tropical cyclone.  相似文献   

Numerical Simulation of Andhra Severe Cyclone (2003): Model Sensitivity to the Boundary Layer and Convection Parameterization   总被引：1，自引：0，他引：1  

C. V. Srinivas  R. Venkatesan  D. V. Bhaskar Rao  D. Hari Prasad 《Pure and Applied Geophysics》2007,164(8-9):1465-1487

The Andhra severe cyclonic storm (2003) is simulated to study its evolution, structure, intensity and movement using the Penn State/NCAR non-hydrostatic mesoscale atmospheric model MM5. The model is used with three interactive nested domains at 81, 27 and 9 km resolutions covering the Bay of Bengal and adjoining Indian Peninsula. The performance of the Planetary Boundary Layer (PBL) and convective parameterization on the simulated features of the cyclone is studied by conducting sensitivity experiments. Results indicate that while the boundary layer processes play a significant role in determining both the intensity and movement, the convective processes especially control the movement of the model storm. The Mellor-Yamada scheme is found to yield the most intensive cyclone. While the combination of Mellor-Yamada (MY) PBL and Kain-Fritsch 2 (KF2) convection schemes gives the most intensive storm, the MRF PBL with KF2 convection scheme produces the best simulation in terms of intensity and track. Results of the simulation with the combination of MRF scheme for PBL and KF2 for convection show the evolution and major features of a mature tropical storm. The model has very nearly simulated the intensity of the storm though slightly overpredicted. Simulated core vertical temperature structure, winds at different heights, vertical winds in and around the core, vorticity and divergence fields at the lower and upper levels—all support the characteristics of a mature storm. The model storm has moved towards the west of the observed track during the development phase although the location of the storm in the initial and final phases agreed with the observations. The simulated rainfall distribution associated with the storm agreed reasonably with observations.  相似文献   

山东省飞机增雨天气系统云水资源转化特征分析   总被引：5，自引：1，他引：5  

龚佃利  边道相 《气象》2002,28(8):15-19

利用水汽辐合法和水汽凝结法，对山东省1997－1999年春秋季18个降水过程的水汽辐合率、凝结率及降水效率等表征云水资源及其转化的特征量进行计算。分析了南方气旋、西北冷锋等主要降水天气系统以上特征量的地域分布和差别。可为人工增雨作业区域选择和航线设计提供气候背景。  相似文献   

热带气旋灾害指数的估算与应用方法   总被引：21，自引：5，他引：21  

钱燕珍  何彩芬  杨元琴  王继志 《气象》2001,27(1):14-18

根据1949－1999年共50年资料，对影响我国的热带气旋所造成的灾情特点作了评估研究。采用数理统计方法，进行定理的计算，按登陆和外围影响两类主要方式建立灾情指数序列，并在此基础上，客观地划分了灾情等级，用来表示受灾的程度。还采用独立于本资料源的Suffir-Simpson热带气旋灾害指数评估方法和资料进行对比验证，最后提出了一套台风灾害预评估的技术方法。  相似文献   

热带气旋暴雨增幅造成北方特大暴雨的预报   总被引：1，自引：0，他引：1  

曹钢锋  朱官忠  张善君 《气象》1996,22(3):3-7

利用人工神经元网络的非线性决策特性，采用前向多层的误差反向传输网络，研制了一个登陆北上热带气旋暴雨增幅造成北方特大暴雨的预报方法－－能自动判虽有无暴雨增幅及其出现地区的人工神经元分类预报网络。该方法简便客观，试用效果较好，即可投入业务使用。  相似文献   

热带气旋路径预报的动态集成方法   总被引：2，自引：0，他引：2  

王德隽  史久恩  吕玉芳 《热带气象学报》1996,12(3):280-284

用模糊贴近度的判据，对若干个热带气旋路径的客观预报方法建立动态的集成方案。经过２年的预报试验，表明它的总体预报水平较好，适合于台站的业务应用。  相似文献   

气旋爆发性发展过程的动力特征及能量学研究   总被引：19，自引：3，他引：19  

吕筱英  孙淑清 《大气科学》1996,20(1):90-100

本文对不同路径的爆发性气旋进行了动力特征及能量学研究。发现高空大值位涡空气的下伸是气旋爆发性发展的一个重要条件。初生气旋逐渐向强位涡区移近并形成上下位涡区相接的形势。使气旋迅速发展。高空急流与气旋发展有密切关系。发展中的气旋明显地向着急流左侧的辐散区移动。急流的突然加强及高空强风动量的不断下传，构成了下层的强风带及上下一致的急流结构。能量学研究指出在气旋发展前气旋内散度风动能向旋转风动能的转换突然增强。散度风动能在爆发气旋发展时有明显增长。  相似文献   

A STUDY ON THE VARIATIONS OF ANNUAL FREQUENCY FOR TROPICAL CYCLONE IN NORTHWEST PACIFIC DURING THE LAST HUNDRED YEARS     

张光智  张先恭  魏凤英 《热带气象学报(英文版)》1996,2(1):67-75

In this paper, a study on the variation of annual frequency of tropical cyclone (TC) and its relation with SST, Southern Oscillation index, sunspot relative number and number of days for specific circulation patterns was made by using 1884-1988 data of annual frequency for Northwest Pacific TC occurrence, which had been corrected to tendencies.Preliminary results indicated that in the variation of annual TC frequency there exist obvious p.6riods of 21, 31, 15 and 6 years and sustaining periods lasting 12 years in average.Well-defined processes of inflexion were observed in 1931, 1959 and 1977 over the past hundred years.The results also suggested insignificant statistic tendency of annual TC frequency increasing (decreasing) in winter/spring (summer/autumn )in the El Nino years.When the stratosphere was in the zonally westerly phase, the northern zonal circulation would abnormally develop and solar activity would enhance to favour the generation and development of TC.  相似文献