首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 171 毫秒
1.
Following previous studies of the rainfall forecast in Shenzhen owing to landfalling tropical cyclones(TCs), a nonparametric statistical scheme based on the classification of the landfalling TCs is applied to analyze and forecast the rainfall induced by landfalling TCs in the coastal area of Guangdong province, China. All the TCs landfalling with the distance less than 700 kilometers to the 8 coastal stations in Guangdong province during 1950—2013 are categorized according to their landfalling position and intensity. The daily rainfall records of all the 8 meteorological stations are obtained and analyzed. The maximum daily rainfall and the maximum 3 days' accumulated rainfall at the 8 coastal stations induced by each category of TCs during the TC landfall period(a couple of days before and after TC landfalling time) from 1950 to 2013 are computed by the percentile estimation and illustrated by boxplots. These boxplots can be used to estimate the rainfall induced by landfalling TC of the same category in the future. The statistical boxplot scheme is further coupled with the model outputs from the European Centre for Medium-Range Weather Forecasts(ECMWF) to predict the rainfall induced by landfalling TCs along the coastal area. The TCs landfalling in south China from 2014 to 2017 and the corresponding rainfall at the 8 stations area are used to evaluate the performance of these boxplots and coupled boxplots schemes. Results show that the statistical boxplots scheme and coupled boxplots scheme can perform better than ECMWF model in the operational rainfall forecast along the coastal area in south China.  相似文献   

2.
A non-parametric method is used in this study to analyze and predict short-term rainfall due to tropical cyclones(TCs) in a coastal meteorological station. All 427 TCs during 1953-2011 which made landfall along the Southeast China coast with a distance less than 700 km to a certain meteorological station- Shenzhen are analyzed and grouped according to their landfalling direction, distance and intensity. The corresponding daily rainfall records at Shenzhen Meteorological Station(SMS) during TCs landfalling period(a couple of days before and after TC landfall) are collected. The maximum daily rainfall(R-24) and maximum 3-day accumulative rainfall(R-72) records at SMS for each TC category are analyzed by a non-parametric statistical method, percentile estimation. The results are plotted by statistical boxplots, expressing in probability of precipitation. The performance of the statistical boxplots is evaluated to forecast the short-term rainfall at SMS during the TC seasons in 2012 and 2013. Results show that the boxplot scheme can be used as a valuable reference to predict the short-term rainfall at SMS due to TCs landfalling along the Southeast China coast.  相似文献   

3.
登陆热带气旋降水增幅的合成诊断分析   总被引:1,自引:0,他引:1  
利用NCEP/NCAR再分析资料,采用动态合成分析方法,对登陆后降水增幅类和非增幅类热带气旋的大尺度环流特征做了合成分析和动力诊断.结果表明:增幅类热带气旋处于强经向型环流之中,中高纬度为阻塞形势,高层有急流入口区南侧的强辐散,并与西风槽相互叠加;低层有急流和水汽通道的长时间联结;热带气旋东侧还有次级环流相伴.非增幅类热带气旋环流背景相对平直,高空辐散弱,无西风槽叠加;低空急流减弱迅速,且水汽通道较早出现断裂;无次级环流出现.增幅类热带气旋高层存在显著非地转运动,高层南风急流入口区的强次地转运动和降水增幅紧密相关.  相似文献   

4.
Interannual variability of landfalling tropical cyclones(TCs) in China during 1960-2010 is investigated.By using the method of partial least squares regression(PLS-regression),canonical ENSO and ENSO Modoki are identified to be the factors that contribute to the interannual variability of landfalling TCs.El Ni o Modoki years are associated with a greater-than-average frequency of landfalling TCs in China,but reversed in canonical El Ni o years.Significant difference in genesis locations of landfalling TCs in China for the two kinds of El Ni o phases occurs dominantly in the northern tropical western North Pacific(WNP).The patterns of low-level circulation anomalies and outgoing longwave radiation(OLR) anomalies associated with landfalling TC genesis with different types of El Ni o phases are examined.During canonical El Ni o years,a broad zonal band of positive OLR anomalies dominates the tropical WNP,while the circulation anomalies exhibit a meridionally symmetrical dipole pattern with an anticyclonic anomaly in the subtropics and a cyclonic anomaly near the tropics.In El Ni o Modoki years,a vast region of negative OLR anomalies,roughly to the south of 25°N with a strong large-scale cyclonic anomaly over the tropical WNP,provides a more favorable condition for landfalling TC genesis compared to its counterpart during canonical El Ni o years.For more landfalling TCs formed in the northern tropical WNP in El Ni o Modoki years,there are more TCs making landfall on the northern coast of China in El Ni o Modoki years than in canonical El Ni o years.The number of landfalling TCs is slightly above normal in canonical La Ni a years.Enhanced convection is found in the South China Sea(SCS) and the west of the tropical WNP,which results in landfalling TCs forming more westward in canonical La Ni a years.During La Ni a Modoki years,the landfalling TC frequency are below normal,owing to an unfavorable condition for TC genesis persisting in a broad zonal band from 5°N to 25°N.Since the western North Pacific subtropical high(WNPSH) in La Ni a Modoki years is located in the westernmost region,TCs mainly make landfall on the south coast of China.  相似文献   

5.
Effect of ENSO on landfalling tropical cyclones over the Korean peninsula   总被引:2,自引:0,他引:2  
The effect of ENSO on landfalling tropical cyclones (TCs) over the Korean Peninsula is examined. It is found that although the landfalling frequency does not show any statistically significant difference among ENSO phases, the landfalling tracks are shifted northward in response to the decrease in Niño-3.4 index. In the neutral ENSO phase, many TCs pass through mainland China before landfalling over the Korean Peninsula due to the westward expansion of the western North Pacific subtropical high. Therefore, the landfalling TC intensity over the Korean Peninsula in the neutral phase is similar to that in the La Niña phase because more than half of those TCs made landfall over mainland China. However, it is found that the preceding winter ENSO phases are not related to the landfalling TC activity over the Korean Peninsula during summer.  相似文献   

6.
登陆中国大陆、海南和台湾的热带气旋及其相互关系   总被引:9,自引:1,他引:8  
首先,针对登陆中国热带气旋的登陆地点资料仅为地名的现状,利用1951-2004年西北太平洋热带气旋资料和登陆中国热带气旋资料,研究制定了登陆资料信息化方案.该方案包括海岸线近似、登陆位置计算、其他特征量计算和误差订正4个方面.对资料信息化结果的分析表明:信息化登陆资料效果是良好的.在此基础上,对登陆中国热带气旋的基本气候特征进行研究,重点分析了在大陆、海南和台湾登陆的3类热带气旋以及它们的相互关系.结果表明:登陆热带气旋频繁的地区为台湾东部沿海、福建至雷州半岛沿海和海南东部沿海;台湾东部沿海和浙江沿海部分地区是登陆热带气旋平均强度最大的地区,平均登陆强度达到台风级别,其中台湾南端的平均登陆强度为最强,达到强台风级别;5-11月为热带气旋登陆中国季节,集中期为7-9月,8月最多;登陆热带气旋的强度主要集中在热带低压-台风,尤其以强热带风暴和台风最多.对于全部大陆、海南和台湾三地,50多年来登陆热带气旋频数都存在不同程度的减少趋势,但只有登陆海南热带气旋的减少趋势是显著的;而所有登陆风暴(含以上强度)频数均无明显增多或减少趋势.总体而言,登陆大陆的TC最多、初旋最早、终旋最晚、登陆期最长;登陆海南的TC居中;而登陆台湾的TC最少、初旋最晚、终旋最早、登陆期最短.从登陆方式看,登陆一地的TC最多、登陆两地的TC次之,分别占总数的79.2%和20.6%,仅有1个TC登陆三地.在登陆两地的TC中,经台湾登陆大陆的TC频数最多、强度减弱最快,经海南登陆大陆的TC频数次之、强度减弱较慢,经大陆登陆海南的TC频数排行第3、强度减弱较快.  相似文献   

7.
This study examines the long-term change in the threat of landfalling tropical cyclones(TCs) in East Asia over the period 1975–2020 with a focus on rapidly intensifying(RI) TCs. The increase in the annual number of RI-TCs over the western North Pacific and the northwestward shift of their genesis location lead to an increasing trend in the annual number of landfalling RI-TCs along the coast of East Asia. The annual power dissipation index(PDI), a measure of the destructive potential of RI-TCs at landfall, also shows a significant increasing trend due to increases in the annual frequency and mean landfall intensity of landfalling RI-TCs. The increase in mean landfall intensity is related to a higher lifetime maximum intensity(LMI) and the LMI location of the landfalling RI-TCs being closer to the coast. The increase in the annual PDI of East Asia is mainly associated with landfalling TCs in the southern(the Philippines, South China, and Vietnam) and northern parts(Japan and the Korean Peninsula) of East Asia due to long-term changes in vertical wind shear and TC heat potential. The former leads to a northwestward shift of favorable environments for TC genesis and intensification, resulting in the northwestward shift in the genesis, RI, and LMI locations of RI-TCs. The latter provides more heat energy from the ocean for TC intensification, increasing its chances to undergo RI.  相似文献   

8.
Coastal urban areas are prone to serious disasters caused by landfalling tropical cyclones(TCs). Despite the crucial role of urban forcing in precipitation, how fine-scale urban features impact landfalling TC precipitation remains poorly understood. In this study, high-resolution ensemble simulations of Typhoon Rumbia(2018), which crossed the Yangtze River Delta urban agglomeration, were conducted to analyze the potential urban impact on TC precipitation. Results show that the inner-core rainfal...  相似文献   

9.
台风登陆衰减后造成降水加强的概况   总被引:4,自引:3,他引:1       下载免费PDF全文
对1965-2008年101例登陆台风衰减后3d内仍存在较强降水的天气过程,运用客观分离方法及其改进方案,分离提取了台风降水(Tropical Cyclone Precipitation;TCP),结果表明:即使登陆台风衰减为热带低压或停编后,因台风系统的存在而产生高强度降水是一种普遍现象,仍旧是预报服务中需要高度关注的问题.采用气候趋势系数和功率谱等方法得到TCP及台风的气候特征:台风衰减点的位置分布具有很强的区域性,与南岭、武夷山脉的走势大致吻合;台风衰减后降水并非单纯性减少,随着时间的推移,空间分布具有向北、向西扩散的特点,特别是中纬度地区的江汉一江淮一带,仍然是防灾减灾的重点.对于衰减后降水反而加强的台风,防御重点可以有针对性地对登陆华南类和登陆华东类两类路径的台风展开.  相似文献   

10.
Using data of tropical cyclones making landfall in China between May and October each year during the 1951-2015 period from the Shanghai Typhoon Institute, China Meteorological Administration (CMA-STI) Tropical Cyclone (TC) Best Track Dataset, we developed a method of rapid classification of TC tracks based on their average movement velocities and noted three types of tracks: a westward type, a northwestward type, and a northward type. We compared the climate characteristics of the westward and northward types and discuss their corresponding causes. The results show that the westward and northward types account for more than 80% of all TCs making landfall in China. Their climate characteristics, such as the frequency, landfall intensity, duration over land, velocity over land, movement distance over land, and other changes, show both similarities and differences. Both TC types show significant increases in their over-land durations, indicating that the effects of these landfalling TCs are increasing. However, the causes of these two TC types are similar and different in certain respects. The changes in large-scale steering flows have significantly affected the frequencies and over-land velocities of the landfalling TCs of the westward and northward types. In addition, differences between the changes in formation locations of the westward and northward types may lead to significant difference in their landfall intensities.  相似文献   

11.
近30a登陆我国的西北太平洋热带气旋活动的时空变化特征   总被引:5,自引:0,他引:5  
采用1979—2006年美国联合台风预警中心的热带气旋(tropical cyclone,TC)资料,对登陆我国的西北太平洋(Northwest Pacific,NWP)TC强度、路径、登陆地点的气候特征、年际变化及其演变趋势进行了统计分析。结果表明:登陆我国的TC以发源于西北太平洋的西侧以及南海中、北部为主,并且在NWP西南区生成的登陆我国的TC基本以西北移动路径为主,而在NWP西北侧和南海生成的登陆我国的TC多为打转或移动路径转向;登陆我国的TC不仅在强度上具有明显增强的变化规律,而且在登陆位置上存在向东北方向偏移的演变趋势,使得登陆厦门以北区域的TC数量具有增加的趋势,而登陆厦门以南的TC数量存在减少的趋势;登陆我国的NWP TC移动路径存在年代际的演变特征。  相似文献   

12.
The Dynamical-Statistical-Analog Ensemble Forecast model for landfalling tropical cyclones (TCs) precipitation (DSAEF_LTP) utilises an operational numerical weather prediction (NWP) model for the forecast track, while the precipitation forecast is obtained by finding analog cyclones, and making a precipitation forecast from an ensemble of the analogs. This study addresses TCs that occurred from 2004 to 2019 in Southeast China with 47 TCs as training samples and 18 TCs for independent forecast experiments. Experiments use four model versions. The control experiment DSAEF_LTP_1 includes three factors including TC track, landfall season, and TC intensity to determine analogs. Versions DSAEF_LTP_2, DSAEF_LTP_3, and DSAEF_LTP_4 respectively integrate improved similarity region, improved ensemble method, and improvements in both parameters. Results show that the DSAEF_LTP model with new values of similarity region and ensemble method (DSAEF_LTP_4) performs best in the simulation experiment, while the DSAEF_LTP model with new values only of ensemble method (DSAEF_LTP_3) performs best in the forecast experiment. The reason for the difference between simulation (training sample) and forecast (independent sample) may be that the proportion of TC with typical tracks (southeast to northwest movement or landfall over Southeast China) has changed significantly between samples. Forecast performance is compared with that of three global dynamical models (ECMWF, GRAPES, and GFS) and a regional dynamical model (SMS-WARMS). The DSAEF_LTP model performs better than the dynamical models and tends to produce more false alarms in accumulated forecast precipitation above 250 mm and 100 mm. Compared with TCs without heavy precipitation or typical tracks, TCs with these characteristics are better forecasted by the DSAEF_LTP model.  相似文献   

13.
城市效应对登陆热带气旋妮妲降水影响的模拟   总被引:2,自引:2,他引:0       下载免费PDF全文
运用中尺度数值模式WRF耦合城市冠层模式(urban canopy model,UCM),对2016年登陆深圳的热带气旋妮妲(1604)(以下简称妮妲)进行数值模拟。高分辨率数值模拟较好地再现了妮妲登陆前后的强度、路径和累积降水。利用城市化过程当中城市冠层对热带气旋降水的敏感性试验结果表明:城市冠层会减弱对流运动和水汽的输送,导致热带气旋登陆后珠江口城市群区域累积降水量略减少。应用最新的土地利用资料进行的城市下垫面敏感性试验结果表明:由于城市下垫面粗糙度增加,造成登陆地面风的减速,强度减弱,潜热通量与2 m高度比湿相应减小;城市下垫面粗糙度增加会加强该区域垂直对流运动以及不稳定能量增加,有利于降水增强,尤其在城市化下垫面处,热带气旋登陆后6 h累积降水增加量最大可超过20 mm。总体而言,对登陆热带气旋降水而言,耦合城市冠层使城市区域热带气旋降水减少,但在数值模拟中城市冠层影响作用不显著。城市化下垫面对登陆热带气旋暴雨的增幅作用明显,在登陆热带气旋降水预报中应重视。  相似文献   

14.
A new synthesized index for estimating the hazard of both accumulated strong winds and heavy rainfall from a tropical cyclone (TC) is presented and applied to represent TC potential hazard over Southeast China. Its relationship with the East Asian westerly jet in the upper troposphere is also investigated. The results show that the new TC potential hazard index (PHI) is good at reflecting individual TC hazard and has significantly higher correlation with economic losses. Seasonal variation of TC-PHI shows that the largest TC-PHI on average occurs in July-August, the months when most TCs make landfall over mainland China. The spatial distribution of PHI at site shows that high PHI associated with major landfall TCs occurs along the southeast coast of China. An East Asian westerly jet index (EAWJI), which represents the meridional migration of the westerly jet, is defined based on two regions where significant correlations exist between TC landfall frequency and zonal wind at 200 hPa. Further analyses show that an anomalous easterly steering flow occurred above the tracks of TCs, and favored TCs making landfall along the southeast coast of China, leading to an increase in the landfall TC when the EAWJ was located north of its average latitude. Meanwhile, anomalous easterly wind shear and positive anomaly in low-level relative vorticity along TCs landfall-track favored TC development. In addition, anomalous water vapor transport from westerly wind in the South China Sea resulted in more condensational heating and an enhanced monsoon trough, leading to the maintenance of TC intensity for a longer time. All of these environmental factors increase the TC potential hazard in Southeast China. Furthermore, the EAWJ may affect tropical circulation by exciting meridional propagation of transient eddies. During a low EAWJI phase in July-August, anomalous transient eddy vorticity flux at 200 hPa propagates southward over the exit region of the EAWJ, resulting in eddy vorticity flux convergence and the weakening in the zonal westerly flow to the south of the EAWJ exit region, producing a favorable upper-level circulation for a TC making landfall.  相似文献   

15.
A dataset entitled "A potential risk index dataset for landfalling tropical cyclones over the Chinese mainland" (PRITC dataset V1.0) is described in this paper, as are some basic statistical analyses. Estimating the severity of the impacts of tropical cyclones (TCs) that make landfall on the Chinese mainland based on observations from 1401 meteorological stations was proposed in a previous study, including an index combining TC-induced precipitation and wind (IPWT) and further information, such as the corresponding category level (CAT_IPWT), an index of TC-induced wind (IWT), and an index of TC-induced precipitation (IPT). The current version of the dataset includes TCs that made landfall from 1949–2018; the dataset will be extended each year. Long-term trend analyses demonstrate that the severity of the TC impacts on the Chinese mainland have increased, as embodied by the annual mean IPWT values, and increases in TC-induced precipitation are the main contributor to this increase. TC Winnie (1997) and TC Bilis (2006) were the two TCs with the highest IPWT and IPT values, respectively. The PRITC V1.0 dataset was developed based on the China Meteorological Administration's tropical cyclone database and can serve as a bridge between TC hazards and their social and economic impacts.  相似文献   

16.
The data of landfalling tropical cyclones (TCs) in China and ENSO events and the NinoZ index during 1951 to 2005 were used to study the relationships between ENSO and landfalling TCs in China. ENSO events from July to September have obvious effects on landfalling TCs in China. When El Nio persists throughout the months, the frequency of landfalling TCs is less than normal, the season of landfalling TCs is shorter, the annually first landfall is later, the annually last landfall is earlier, and the mean int...  相似文献   

17.
In recent work, three physical factors of the Dynamical-Statistical-Analog Ensemble Forecast Model for Landfalling Typhoon Precipitation (DSAEF_LTP model) have been introduced, namely, tropical cyclone (TC) track, TC landfall season, and TC intensity. In the present study, we set out to test the forecasting performance of the improved model with new similarity regions and ensemble forecast schemes added. Four experiments associated with the prediction of accumulated precipitation were conducted based on 47 landfalling TCs that occurred over South China during 2004-2018. The first experiment was designed as the DSAEF_LTP model with TC track, TC landfall season, and intensity (DSAEF_LTP-1). The other three experiments were based on the first experiment, but with new ensemble forecast schemes added (DSAEF_LTP-2), new similarity regions added (DSAEF_LTP-3), and both added (DSAEF_LTP- 4), respectively. Results showed that, after new similarity regions added into the model (DSAEF_LTP-3), the forecasting performance of the DSAEF_LTP model for heavy rainfall (accumulated precipitation ≥250 mm and ≥100 mm) improved, and the sum of the threat score (TS250 + TS100) increased by 4.44%. Although the forecasting performance of DSAEF_LTP-2 was the same as that of DSAEF_LTP-1, the forecasting performance was significantly improved and better than that of DSAEF_LTP-3 when the new ensemble schemes and similarity regions were added simultaneously (DSAEF_LTP-4), with the TS increasing by 25.36%. Moreover, the forecasting performance of the four experiments was compared with four operational numerical weather prediction models, and the comparison indicated that the DSAEF_LTP model showed advantages in predicting heavy rainfall. Finally, some issues associated with the experimental results and future improvements of the DSAEF_LTP model were discussed.  相似文献   

18.
Yao  Xiuping  Zhao  Dajun  Li  Ying 《Acta Meteorologica Sinica》2020,34(1):150-162

We used tropical cyclone (TC) best track data for 1949–2016, provided by the Shanghai Typhoon Institute, China Meteorological Administration (CMA-STI), and a TC size dataset (1980-2016) derived from geostationary satellite infrared images to analyze the statistical characteristics of autumn TCs over the western North Pacific (WNP). We investigated TC genesis frequency, location, track density, intensity, outer size, and landfalling features, as well as their temporal and spatial evolution characteristics. On average, the number of autumn TCs accounted for 42.1% of the annual total, slightly less than that of summer TCs (42.7%). However, TCs classified as strong typhoons or super typhoons were more frequent in autumn than in summer. In most years of the 68-yr study period, there was an inverse relationship between the number of autumn TCs and that of summer TCs. The genesis of autumn TCs was concentrated at three centers over the WNP: the first is located near (14°N, 115°E) over the northeastern South China Sea and the other two are located in the vast oceanic area east of the Philippines around (14°N, 135°E) and (14°N, 145°E), respectively. In terms of intensity, the eight strongest TCs during the study period all occurred in autumn. It is revealed that autumn TCs were featured with strong typhoons and super typhoons, with the latter accounting for 28.1% of the total number of autumn TCs. Statistically, the average 34-knot radius (R34) of autumn TCs increased with TC intensity. From 1949 to 2016, 164 autumn TCs made landfall in China, with an average annual number of 2.4. Autumn TCs were most likely to make landfall in Guangdong Province, followed by Hainan Province and Taiwan Island.

  相似文献   

19.
利用每6小时一次的NCEP再分析资料,对华南地区登陆前突然减弱和突然增强的两类热带气旋(TC)进行大尺度诊断分析,结果表明:(1)突然增强的TC位于副高的西南侧或南侧,低空有明显的西南气流卷入TC内部,而突然减弱的TC基本在副高西侧或西北侧;(2)突然增强TC的低空辐合、高空辐散均较强;(3)充足的水汽输送是TC登陆前突然增强的另一重要原因。  相似文献   

20.
近58年来登陆中国热带气旋气候变化特征   总被引:12,自引:1,他引:11  
杨玉华  应明  陈葆德 《气象学报》2009,67(5):689-696
利用1949-2006年<台风年鉴>和<热带气旋年鉴>资料,主要分析了1949-2006年登陆中国热带气旋的频数、登陆位置、登陆季节延续期和登陆强度等要素及其概率分布的年际和年代际变化特征.结果表明:近58年来,登陆中国热带气旋年频数有减少趋势,但登陆时达台风强度的年频数变化不明显;按登陆地点分区统计发现,登陆华南地区的热带低压及(强)热带风暴年频数以减少为主,而登陆东部地区的热带气旋年频数变化不明显.登陆点历年最北位置(最南位置)有南移(弱的北移)趋势,导致登陆点历年南北最大纬度差逐渐减小,这表明热带气旋登陆区域更为集中,在23°-35°N增多,而在35°N以北和23°N以南以减少为主.登陆中国热带气旋季节延续期缩短了近1个月.热带气旋年平均登陆强度及其概率分布偏度有增加趋势,表明登陆的强台风有增加;登陆中国华南和东部地区的台风强度都有增强趋势,前者比后者趋势更明显.另外,热带气旋年最大登陆强度差长期呈现减小的趋势.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号