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In order to provide an operational reference for tropical cyclone precipitation forecast,this study investigates the spatial distributions of precipitation associated with landfalling tropical cyclones(TCs) affecting China using Geostationary Meteorological Satellite 5(GMS5)-TBB dataset.All named TCs formed over the western North Pacific that made direct landfall over China during the period 2001-2009 are included in this study.Based on the GMS5-TBB data,this paper reveals that in general there are four types of distribution of precipitation related to landfalling TCs affecting China.(a) the South-West Type in which there is a precipitation maximum to the southwestern quadrant of TC;(b) the Symmetrical South Type in which the rainfall is more pronounced to the south side of TC in the inner core while there is a symmetrical rainfall distribution in the outer band region;(c) the South Type,in which the rainfall maxima is more pronounced to the south of TC;and(d) the North Type,in which the rainfall maxima is more pronounced to the north of TC.Analyses of the relationship between precipitation distributions and intensity of landfalling TCs show that for intensifying TCs,both the maximum and the coverage area of the precipitation in TCs increase with the increase of TC intensity over northern Jiangsu province and southern Taiwan Strait,while decreasing over Beibu Gulf and the sea area of Changjiang River estuary.For all TCs,the center of the torrential rain in TC shifts toward the TC center as the intensity of TC increases.This finding is consistent with many previous studies.The possible influences of storm motion and vertical wind shear on the observed precipitation asymmetries are also examined.Results show that the environmental vertical wind shear is an important factor contributing to the large downshear rainfall asymmetry,especially when a TC makes landfall on the south and east China coasts.These results are also consistent with previous observational and numerical studies. 相似文献
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新一代区域海-气-浪耦合台风预报系统 总被引：1，自引：0，他引：1
依托国家重点基础研究（973）计划项目"上层海洋对台风的响应和调制机理研究"，中国气象局上海台风研究所联合国家海洋局的相关单位，通过实施近海台风的外场观测科学试验、加强台风边界层（特别是海气相互作用）物理过程诊断分析及参数化方案等的研究，建立并改进了台风强度预报的海-气-浪耦合预报模式系统，并在此基础上发展了台风强度的集合预报技术，在历史典型台风个例和2016-2017年台汛期的业务化测试中表现出良好的预报性能。 相似文献
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第二类热成风螺旋度对登陆台风降水的诊断能力分析台风泰利个例研究 总被引：2，自引：0，他引：2
文中利用中尺度数值模式MM5模拟了台风泰利的登陆过程,模拟的台风路径、天气形势和降水都与观测基本一致,能够很好地反映出真实的天气过程.再利用数值模拟结果,研究了第二类热成风螺旋度(H_2)对登陆台风泰利降水的诊断能力,结果表明它对深入内陆的台风强降水具有较好的诊断能力,而对刚登陆前后的台风降水诊断能力不如经典螺旋度.特别地,H_2在提前1 h时与泰利降水达到最高相关系数,且在提前1-5 h时,它与降水的相关性比经典螺旋度的高,表现出十分显著的预示降水增幅的能力.进一步分析表明,在刚登陆前后,泰利台风中心850-200 hPa的风场垂直切变较小(约5 m/s),其最强降水出现在路径右侧300 km半径范围以内,与低空的正温度平流、低空辐合、高空辐散等无明显的关系,而低空相对涡度能够很好地反映降水的变化,这是经典螺旋度与降水在这一阶段相关性优于H_2的主要原因.而在深入内陆后,台风泰利本体环流减弱,受北部西风槽的影响逐渐增强,环境风场垂直切变迅速增大,发生强降水的庐山和大别山区处于顺垂直风切变方向左侧.在东北向的垂直风切变情况下,庐山和大别山强降水区上空有向东的高空急流出流,强高空辐散诱发垂直次级环流,从而激发对流,形成强上升运动区,因此H_2的诊断优势在这一阶段表现得最清楚. 相似文献
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本文利用WRF模式对近海台风“烟花”及“查帕卡”影响2021年7月19日至21日河南极端暴雨的过程进行数值模拟。控制试验（CTL）对台风路径、强度、大尺度环流形势,以及河南暴雨的强度和空间分布型等均给出合理的模拟,基本再现了本次河南极端暴雨的发展过程。敏感性试验表明,在移除台风“烟花”后,副热带高压系统显著南压并在南侧形成东南风急流,河南地区的南风分量减弱、东风增强,东西方向的水汽输送占主导,有利于降水分布型由CTL试验的南—北向转变为东—西向;另一方面,由于低层东南风急流相较于移除“烟花”前的东风急流偏弱,河南降雨区的局地辐合减弱,水汽通量净流入值较CTL试验降低5.81%,且中纬度冷气团西移减慢,引起局地相当位温梯度减弱,最终导致移除台风“烟花”试验的降雨强度偏弱。移除台风“查帕卡”后,大尺度环流形势几乎未受影响,河南南侧的水汽输送略有减弱,因此强降水分布基本与CTL试验类似,降雨强度略有减小。与台风“烟花”相比,“查帕卡”对河南暴雨的影响较弱。 相似文献
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本文提供了一个描述西藏地区年、季降水量空间分布的估算模型.利用卫星遥测数字化地形高程资料和西藏地区仅有的27个常规气象站的多年平均降水整编资料,根据地形坡向站点分为三类.再采用多元逐步回归方法,建立西藏地区的年、季降水量和经度、纬度、海拔高度、坡度、坡向、遮蔽度等6个地理、地形因子之间的关系模型,估算西藏地区降水量的空间分布.结果表明,此方法建立的关于西藏地区降水量与诸因子之间方程的相关性显著,平均绝对误差、相对误差分别为093mm和116%,对估算模型进行F检验,均通过置信度为095的相关检验,回归效果较显著.分析表明估算降水能够定量、定性地再现西藏地区的实际降水分布. 相似文献
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A heavy rainfall process, which occurred in Shanghai during 5-6 August, 2001 from a landfalling tropical depression (TD),is examined with a control numerical experiment based on MM5 model. It is found that the contours of generalized equivalent potential temperature (θ*) are almost vertical with respect to horizontal surfaces near the TD center and more densely distributed than those of equivalent potential temperature (θe).Because the atmosphere is non-uniformly saturated in reality, θ* takes the place of θe in the definition of convective vorticity vector (CVV) so that a new vector, namely the generalized convective vorticity vector (CVV*), is applied in this study. Since CVV* can reflect both the secondary circulation and the variation of horizontal moist baroclinicity, the vertical integration of vertical component of CVV* is found, in this study, to represent the rainfall areas in the TD case better than potential vorticity (PV), moist potential vorticity (MPV), generalized moist potential vorticity (Pm), and CVV, with high-value area of CVV* corresponding to heavy-rainfall area. Moreover, the analysis from CVV* implies that the Hangzhou Bay might play an important role in the heavy rain process. A sensitivity experiment without the Hangzhou Bay is then designed and compared with the control run. It is found that the CVV* becomes weaker than that in the control run, implying that the elimination of Hangzhou Bay results in reduced rainfall. Further analyses show that the Hangzhou Bay provides sufficient water vapor and surface heat flux to the TD system, which is very important to the genesis and development of mesoscale cloud clusters around the TD and the associated heavy rainfall. 相似文献
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针对2019年影响中国的8个台风,利用面向降水对象的CRA(contiguous rain area)方法研究了欧洲中期天气预报中心确定性预报的降水误差来源,及其在不同预报时段和降水量级下的变化趋势,分析了台风路径预报误差与降水对象的CRA位置误差之间的相关性,对比计算了台风路径修正与CRA shifting方法对于改进降水预报的作用,并评估了台风降水概率分布、径向分布和非对称分布的预报误差。结果表明:总体而言,台风降水预报的主要误差来自于位置误差和形态误差;除特大量级降水以外,台风降水对象的CRA位置误差与路径误差显著相关,通过修正台风路径能改进降水预报,但其效果要逊于CRA shifting方法;预报的台风降水概率密度分布形态与观测总体上较为一致,但台风核心区内的预报降水强度均大于观测;台风登陆或靠近我国沿海前后,预报降水较观测更靠近台风中心,且略滞后于观测,预报降水的非对称性明显弱于观测。 相似文献
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TERRAIN IMPACT ON THE PRECIPITATION OF LANDFALLING TYPHOON TALIM 总被引：4，自引：0，他引：4
The impact of terrains on the precipitation of landfalling typhoon Talim (2005) over mainland
China is investigated using the fifth-generation Pennsylvania State University-National Center for
Atmospheric Research Mesoscale Model. The simulated precipitation of simulated typhoon (the control)
matches the observations closely. To compare with the control simulation, four sensitivity simulations were
carried out in which terrains of Wuyi Mountain, Lushan, Dabieshan, and both Lushan and Dabieshan are
completely removed respectively, but other surface properties were retained. It is found that the complex
terrains of Wuyi Mountain, Lushan and Dabieshan have a significant impact on the rainfall intensity and
distribution of Talim. As the terrains are removed, the rainfall is decreased very greatly and the rainfall in
inland area is decreased much more than that in the coastal area. Besides, the rainfall distribution near the
Lushan and Dabieshan is spread much more westward compared with the control simulation. Further
analysis shows that the Wuyi Mountain would increase both the lower level air convergence and the upper
level air divergence for Talim that just made landfall and thus it would contribute to the convection and
increase rainfall intensity. It can be concluded that the terrains of Wuyi Mountain, Lushan and Dabieshan
have obvious impacts on the Talim rainfall, and their impacts are different in various landfalling periods.
The present study is a useful attempt to explore the influence of orography on the TCs in mainland China. 相似文献
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