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1.
The effect of climate change on tropical cyclone intensity has been an important scientific issue for a few decades.Although theory and modeling suggest the intensification of tropical cyclones in a warming climate,there are uncertainties in the assessed and projected responses of tropical cyclone intensity to climate change.While a few comprehensive reviews have already provided an assessment of the effect of climate change on tropical cyclone activity including tropical cyclone intensity,this review focuses mainly on the understanding of the effect of climate change on basin-wide tropical cyclone intensity,including indices for basin-wide tropical cyclone intensity,historical datasets used for intensity trend detection,environmental control of tropical cyclone intensity,detection and simulation of tropical cyclone intensity change,and some issues on the assessment of the effect of climate change on tropical cyclone intensity.In addition to the uncertainty in the historical datasets,intertwined natural variabilities,the considerable model bias in the projected large-scale environment,and poorly simulated inner-core structures of tropical cyclones,it is suggested that factors controlling the basin-wide intensity can be different from individual tropical cyclones since the assessment of the effect of climate change treats tropical cyclones in a basin as a whole.  相似文献   

2.
 Based on tropical cyclone track dataset in the western North Pacific from China Meteorological Administration (CMA), variations in frequency and intensity of tropical cyclones (TCs) in the western North Pacific, affecting-China TCs (ACTCs) and landfall TCs (LTCs) achieving a typhoon intensity during 1957-2004 were studied. Frequencies of strong tropical cyclones showed significant decreasing trends from 1957 to 2004 and the linear trend was much greater when the intensity was stronger. There was no linear trend in the portion of strong tropical cyclones achieving a typhoon (TY) intensity, while those reaching a strong typhoon (STY) and a super typhoon (SuperTY) intensity showed decreasing trends during 1957-2004. The maximum intensities of TCs, ACTCs and LTCs all decreased during the period of 1957-2004. The mean intensities of TCs and ACTCs displayed decreasing trends and the mean intensity of LTCs achieving a TY intensity also showed a decreasing trend.  相似文献   

3.
Analysis of the climatic characteristics of the tropical cyclones that affect China yields several interesting features. The frequency of these tropical cyclones tended to decrease from 1951 to 2005, with the lowest frequency in the past ten years. The decrease in the frequency of super typhoons is particularly significant. The main season of tropical cyclone activities is from May to November, with an active period from July to September. There are three obvious sources of these tropical cyclones and they vary with seasons and decades. Their movement has also changed with seasons. On average, these tropical cyclones affect China for 5.6 months annually and the period of influence decreases in the past decades. An analysis of daily data indicates that the days of typhoon influence are shorter in winter and spring and longer in summer. The frequency of tropical cyclones is the largest over southeastern China, decreasing northwestward. Taiwan is the region that is affected by tropical cyclones most frequently. The average annual precipitation associated with tropical cyclones has also decreased gradually northwestward from southeastern China.  相似文献   

4.
Based on the Joint Typhoon Warning Center (JTWC) best-track dataset between 1965 and 2009 and the characteristic parameters including tropical cyclone (TC) position, intensity, path length and direction, a method for objective classification of the Northwestern Pacific tropical cyclone tracks is established by using K-means Clustering. The TC lifespan, energy, active season and landfall probability of seven clusters of tropical cyclone tracks are comparatively analyzed. The characteristics of these parameters are quite different among different tropical cyclone track clusters. From the trend of the past two decades, the frequency of the western recurving cluster (accounting for 21.3% of the total) increased, and the lifespan elongated slightly, which differs from the other clusters. The annual variation of the Power Dissipation Index (PDI) of most clusters mainly depended on the TC intensity and frequency. However, the annual variation of the PDI in the northwestern moving then recurving cluster and the pelagic west-northwest moving cluster mainly depended on the frequency.  相似文献   

5.
This is a study to compare three selected tropical cyclone datasets separately compiled by CMA Shanghai Typhoon Institute (CMA_SHI), the Joint Typhoon Warning Center (JTWC), and the Japan Meteorological Agency (JMA). The annual frequencies, observation times and destructive power index as the characteristic quantities are investigated of the tropical cyclones over the western North Pacific. The comparative study has resulted in the following findings: 1) Statistical gaps between the datasets compared are narrowing down as the intensity of tropical cyclones increases. 2) In the context of interdecadal distribution, there is for the 1950s a relatively large gap between the datasets, as compared with a narrowed gap for the period from the mid 1970s to the 1980s, and a recurring widened gap for the mid and late 1990s. Additionally, an approach is proposed in the paper to correct the wind speed data in the TC Yearbook.  相似文献   

6.
Previous numerical studies have focused on the combined effect of momentum and scalar eddy diffusivity on the intensity and structure of tropical cyclones. The separate impact of eddy diffusivity estimated by planetary boundary layer(PBL) parameterization on the tropical cyclones has not yet been systematically examined. We have examined the impacts of eddy diffusion of moisture on idealized tropical cyclones using the Advanced Research Weather Research and Forecasting model with the Yonsei University PBL scheme. Our results show nonlinear effects of moisture eddy diffusivity on the simulation of idealized tropical cyclones. Increasing the eddy diffusion of moisture increases the moisture content of the PBL, with three different effects on tropical cyclones:(1) an decrease in the depth of the PBL;(2) an increase in convection in the inner rain band and eyewall; and(3) drying of the lowest region of the PBL and then increasing the surface latent heat flux. These three processes have different effects on the intensity and structure of the tropical cyclone through various physical mechanisms. The increased surface latent heat flux is mainly responsible for the decrease in pressure. Results show that moisture eddy diffusivity has clear effects on the pressure in tropical cyclones, but contributes little to the intensity of wind. This largely influences the wind–pressure relationship, which is crucial in tropical cyclones simulation. These results improve our understanding of moisture eddy diffusivity in the PBL and its influence on tropical cyclones, and provides guidance for interpreting the variation of moisture in the PBL for tropical cyclone simulations.  相似文献   

7.
TROPICAL CYCLONE DAMAGES IN CHINA UNDER GLOBAL WARMING   总被引:1,自引:0,他引:1  
Over the past 25 years, an annual average of 6 to 7 tropical cyclones (TCs) made landfall on China mainland and Hainan Island with an average intensity of 29.9 m/s at landfall and maintained at least tropical storm intensity for 15.6 hours over land, leading to 505 deaths and 37 billion yuan in direct economic loss, which accounted for 0.4% of the annual GDP of China. Although there was little change in the overall landfall frequency, intensity at landfall and overland duration, the annual total direct economic loss increased significantly due to the rapid economic development over the past 25 years. Under global warming, the intensity of TCs that made landfall on Hainan decreased but the overland duration and frequency of TCs that made landfall on Fujian and Zhejiang increased. At the national and provincial levels, the ratio of the direct economic loss to GDP and casualties caused by landfall tropical cyclones decreased, suggesting the effectiveness of disaster prevention and reduction in China.  相似文献   

8.
Based on the barotropic primitive equation in the polar coordinate system and the appropriate assumption, we obtained the mathematical equation of orographic forcing on unit mass air parcel. With the consideration of the frictional stress of the sea and land, supposing that parcel velocity in tropical cyclones is in linear variation and that the distribution of surface pressure is circular, a set of equations are derived, which describe the impact of orographic slope error, the central pressure error and position error of tropical cyclones on the wind field in the tropical cyclone. Typhoon Wipha (2007) is selected to verify the above interpretation method. The results show that the orographic slope, the frictional coefficient, the intensity and position of the cyclone are the important factors which have great influence on the interpretation of wind information about tropical cyclones. The dynamic interpretation method gives very good results, especially for the coastal area. It is applicable to improving the forecasts of the wind field in tropical cyclones.  相似文献   

9.
In this study,tropical cyclone data from China Meteorological Administration(CMA) and the ECMWF reanalysis data for the period 1958-2001 was used to propose a possible mechanism for the impacts of air-sea interaction on the activity of tropical cyclones(TCs) affecting China.The frequency of TCs affecting China over past 40 years has trended downward,while during the same period,the air-sea interaction in the two key areas of the Pacific region has significantly weakened.Our diagnoses and simulations suggest that air-sea interactions in the central North Pacific tropics and subtropics(Area 1) have an important role in adjusting typhoon activities in the Northwest Pacific in general,and especially in TC activity affecting China.On the contrary,impacts of the air-sea interaction in the eastern part of the South Pacific tropics(Area 2) were found to be rather limited.As both observational analysis and modeling studies show that,in the past four decades and beyond,the weakening trend of the latent heat released from Area 1 matched well with the decreasing Northwest Pacific TC frequency derived from CMA datasets.Results also showed that the weakening trend of latent heat flux in the area was most likely due to the decreasing TC frequency over the Northwest Pacific,including those affecting China.Although our preliminary analysis revealed a possible mechanism through which the air-sea interaction may adjust the genesis conditions for TCs,which eventually affect China,other relevant questions,such as how TC tracks and impacts are affected by these trends,remain unanswered.Further in-depth investigations are required.  相似文献   

10.
An overview of tropical cyclone and tropical meteorology research progress   总被引:17,自引:1,他引:16  
There has been much progress in the study of tropical cyclones and tropical meteorology in China in the past few years. A new atmospheric field experiment of tropical cyclone landfall with the acronym of CLATEX (China Landfalling Typhoon Experiment) was implemented in July-August 2002. The boundary layer characteristics of the target typhoon Vongfong and the mesoscale structural features of other landfalling typhoons were studied. In addition, typhoon track operational forecasting errors in the last decade have been reduced because the operational monitoring equipment and forecast techniques were improved.Some results from the research program on tropical cyclone landfall, structure and intensity change, intensification near coastal waters, interaction between tropical cyclone and mid-latitude circulation, and the interaction among different scales of motion are described in this paper. Four major meteorological scientific experiments in China with international cooperation were implemented in 1998: the South China Sea monsoon field experiment (SCSMEX), the Tibetan Plateau field experiment (TIPEX), the Huaihe River basin energy and water cycle experiment (HUBEX), and the South China heavy rain scientific experiment(HUAMEX). Although these field experiments have different scientific objectives, they commonly relate to monsoon activities and they interact with each other. The valuable intensive observation data that were obtained have already been shared internationally. Some new findings have been published recently.Other research work in China, such as the tropical air-sea interaction, tropical atmospheric circulation,and weather systems, axe reviewed in this paper as well. Some research results have shown that the rainfall anomalies for different regions in China were closely related to the stages of E1 Nifio events.  相似文献   

11.
Based on tropical cyclone track dataset in the western North Pacific from China Meteorological Administration(CMA),variations in frequency and intensity of tropical cyclones(TCs)in the western North Pacific,affecting-China TCs(ACTCs)and landfall TCs(LTCs)achieving a typhoon intensity during 1957-2004 were studied.Frequencies of strong tropical cyclones showed significant decreasing trends from 1957 to 2004 and the linear trend was much greater when the intensity was stronger.There was no linear trend in the portion of strong tropical cyclones achieving a typhoon(TY)intensity,while those reaching a strong typhoon(STY)and a super typhoon(SuperTY)intensity showed decreasing trends during 1957-2004.The maximum intensities of TCs,ACTCs and LTCs all decreased during the period of 1957-2004.The mean intensities of TCs and ACTCs displayed decreasing trends and the mean intensity of LTCs achieving a TY intensity also showed a decreasing trend.  相似文献   

12.
1957-2004年影响我国的强热带气旋频数和强度变化   总被引:2,自引:0,他引:2  
以中国气象局西北太平洋热带气旋资料为基础,分析1957-2004年影响我国并达到台风强度以上的三类热带气旋,即生成热带气旋、影响热带气旋和登陆热带气旋的频数和强度的变化。结果表明:强热带气旋频数在1957-2004年间呈显著减少趋势,强度越强,其减少趋势越明显。近50 a台风以上强度的强热带气旋频次占总频次的比例没有明显的增加或减少趋势,强台风和超强台风比例呈减少趋势。1957-2004年热带气旋的最大强度呈线性减弱趋势,生成热带气旋和影响热带气旋的平均强度亦呈减弱趋势,登陆台风的平均强度也呈减弱趋势。  相似文献   

13.
利用中国地面台站逐日降水资料和中国气象局上海台风研究所整编的热带气旋最佳路径资料研究了1978~2007年影响我国热带气旋降水强度的变化及其对我国东南沿海盛夏降水变化的影响.近30年影响我国东南沿海盛夏的热带气旋降水增加是导致我国东南沿海盛夏降水显著增加的主要原因.仅从热带气旋降水来看,东南沿海和内陆(包括江西、湖南东部和湖北南部)热带气旋降水强度显著增加,而影响热带气旋降水频次略有增加.通过对雨量站与引起降水热带气旋的中心距离的变化分析发现:内陆地区影响热带气旋距离显著下降,近距离热带气旋引起降水的增加,是该区域热带气旋降水强度增加的主要来源;而东南沿海地区近距离热带气旋降水增加不明显,热带气旋降水强度的增加主要由于同距离热带气旋降水强度的增加.热带气旋经过频次的空间的变化结果证实,近30年经过中国沿海的TC个数变化不大,仅福建沿海一带略有增加,而内陆地区则增加明显,且经过该区域时热带气旋移动速度变慢,这均与该区域近距离热带气旋降水的增加一致.  相似文献   

14.
西北太平洋热带气旋频数和强度变化趋势初探   总被引:4,自引:0,他引:4       下载免费PDF全文
利用1951—2006年西北太平洋 (含南海) 热带气旋资料, 研究了不同强度热带气旋的气候变化特征。结果表明:超强台风 (近中心最大风速≥58m/s, 简称超强台风Ⅱ) 频数、强度和初、终旋日期的变化特征都不同于其他级别热带气旋; 西北太平洋热带气旋的总频数有长期减少趋势, 主要由热带低压和超强台风Ⅱ的长期减少趋势引起; 随着热带气旋强度增强, 出现月最大频数的月份逐渐推迟; 超强台风月频数最大值发生在秋季; 超强台风Ⅱ频数的年变化与除了超强台风Ⅰ(近中心最大风速为51~58m/s) 外的其他级别热带气旋反相关; 受超强台风Ⅱ减少影响, 热带气旋年平均最大风速有减小的长期趋势; 热带气旋的初、终旋日期没有显著的长期变化趋势, 但超强台风Ⅱ的初旋日期有推迟趋势, 终旋日期有提前趋势, 发生时间缩短。  相似文献   

15.
登陆中国不同强度热带气旋的变化特征   总被引:4,自引:3,他引:1  
根据《热带气旋等级》国家标准(2006),将热带气旋(TC)划分为热带低压(TD)、热带风暴(TS)、强热带风暴(STS)、台风(TY)、强台风(STY)、超强台风(SSTY)6个等级,利用中国气象局整编的1949—2006年共58年的《台风年鉴》和《热带气旋年鉴》资料,分析了登陆中国大陆、海南和台湾不同强度TC变化特征。结果表明:(1) 不同强度登陆TC频数存在年际和年代际变化,在长期趋势上,TD、TS登陆频数呈现显著的线性递减趋势,STY登陆频数呈现显著增加趋势。(2) 登陆TD、TS、STS存在6—8年的周期变化,TY具有准16年的周期变化。(3) 登陆TD、TS主要生成于南海东北部海面,登陆TY、STY、SSTY多生成于巴士海峡东南部海面和菲律宾以东洋面。(4) 在年代际变化上,南海生成的登陆TD、TS频数有减少趋势,TY、STY有增多趋势。  相似文献   

16.
利用中国气象局上海台风研究所整编的1949—2019年热带气旋数据,统计分析近71 a影响黑龙江省的热带气旋发生时间、频率、强度、移动路径等特征。结果表明:近71 a影响黑龙江的热带气旋共有77个,平均1.08个·a-1,其中有28 a没有热带气旋影响黑龙江;近10 a是黑龙江受热带气旋影响的活跃期,西北太平洋生成的热带气旋频数与影响黑龙江的频数没有直接相关关系,出现El Ni1o或La Ni1a现象时对影响黑龙江的热带气旋起抑制作用;热带气旋影响黑龙江最早出现在5月,最晚出现在9月,8月出现频率最高,“七下八中下”是每年的活跃阶段;在强度上,影响黑龙江的超强台风居多,但近年趋于减少,更多低级别的热带气旋可维持较长生命史北上产生影响;牡丹江市为黑龙江最易受热带气旋影响的地区;按移动路径可将影响黑龙江的热带气旋分为两类,分别为北上热带气旋和偏东路径热带气旋,其中北上热带气旋又可进一步分为七类,其中经朝鲜半岛东转向出现的频次最多,但对黑龙江影响相对较小;经朝鲜半岛北上和高纬东转向更容易给黑龙江带来严重的风雨影响。  相似文献   

17.
热带气旋强度资料的差异性分析   总被引:16,自引:4,他引:16  
余晖  胡春梅  蒋乐贻 《气象学报》2006,64(3):357-363
通过对比西北太平洋3个主要预报中心(中国气象局(CMA)、日本东京台风中心(RSMC Tokyo)和美国联合台风警报中心(JTWC))的16 a数据,分析了不同来源的热带气旋(TC)强度资料的差异性。结果表明:CMA与RSMCTokyo和JTWC的TC强度均值分别相差0.6和1.7 m/s,均通过1%信度的统计检验,即存在显著差异;3个中心对同一TC确定的强度最大差异超过30 m/s;CMA资料的台风数多于RSMC Tokyo和JTWC,年台风频数的均方差也最大,但是3个中心资料的各级TC频数差异均无统计显著性。对比有、无飞机探测时段的资料发现,对TC进行飞机探测可在一定程度上减小各中心在确定TC强度方面的分歧。为了初步了解上述资料问题对TC强度预报的可能影响,采用一个气候持续性预报方法,取不同来源的TC强度资料进行了4 a(2000—2003年)的预报。发现据JTWC资料所得TC强度预报有最大的均方根误差,RSMCTokyo的最小,CMA居中;据CMA和RSMC Tokyo(CMA和JTWC)资料,对相同TC相同时次24 h预报的平均绝对偏差达2.5(4.0)m/s,最大可相差16(21)m/s。可见,西北太平洋TC强度的基本资料问题增加了预报的难度。  相似文献   

18.
60年来西北太平洋上不同强度热带气旋的变化特征   总被引:11,自引:2,他引:9  
利用美国海军联合台风警报中心(JTWC)提供的1945-2005年西北太平洋热带气旋(TC)最佳路径资料统计分析了不同强度TC的时空变化特征.南海北部至巴士海峡以东140°E附近、15°-25°N范围内为不同强度TC出现次数最多的区域,其中巴士海峡东部至140°E附近洋面为强台风和超级台风观测次数最多的区域.TC强度在123°E以西表现为减弱和稳定略占多数,而在123°E以东或20°N以南主要以增强和稳定为主,在20°N以北主要以减弱和稳定为主.热带风暴的平均增强率大于减弱率,而强热带风暴、台风、强台风和超级台风的平均减弱率大于增强率.一般而言,TC的强度越强其加强和减弱的速度都越快.在1年当中,同其他月份相比,6-8月弱TC占的比例相对偏多,而9-11月强TC占的比例相对偏多.不同强度TC的观测次数和个数都存在年、年际或年代际的变化,在长期趋势上,热带风暴的观测次数和形成个数都呈现显著的线性递增趋势,而TC平均强度和其他TC个数均未出现显著的线性递增或递减趋势.在El Ni[AKn~D]o年超级台风个数及其比例显著偏多,而热带风暴、强热带风暴、台风和强台风的总个数显著偏少,TC平均强度显著偏强;而在La Nina年情况相反.  相似文献   

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