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1.
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
2.
Impacts of Four Types of ENSO Events on Tropical Cyclones Making Landfall over Mainland China Based on Three Best-track Datasets简 总被引：1，自引：0，他引：1
Impacts of EI Nino Modoki （ENM）, La Nina Modoki （LNM）, canonical EI Nifio （CEN） and canonical La Nifia （CLN） on tropical cyclones （TCs） that made landfall over mainland China during 1951-2011 are analysed using best-track data from China, the USA and Japan. Relative to cold phase years （LNM and CLN）, landfalling TCs in warm years （ENM and CEN） have a farther east genesis location, as well as longer track lengths and durations, both in total and before landfall. ENM demonstrates the highest landfall frequency, most northerly mean landfall position, and shortest after-landfall sustainability （track length and duration）, which indicate a more frequent and extensive coverage of mainland China by TCs, but with shorter after-landfall influence. CEN has low landfall frequency and the most southerly mean landfall location. LNM has the most westerly genesis location, being significantly farther west than the 1951-2011 average and leading to short mean track lengths and durations both in total or before landfall, all of which are significantly shorter than the 1951-2011 average. Variations in the low-level wind anomaly, vertical wind shear, mid-level relative humidity, steering flow, the monsoon trough and the western Pacific subtropical high （WPSH） can to some extent account for the features of frequency, location, track length and duration of landfalling TCs. Since ENSO Modoki is expected to become more frequent in the near future, the results for ENSO Modoki presented in this paper are of particular significance. 相似文献
3.
Ki-Seon Choi Chun-Chieh Wu Yuqing Wang 《Asia-Pacific Journal of Atmospheric Sciences》2011,47(4):391-397
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
4.
This study examines the influence of the El Niño-Southern Oscillation (ENSO) on the frequency of landfalling tropical cyclones (TCs) in the Korean Peninsula during the TC season, June through October, of the years 1951–2010. An ENSO year is defined when the seasonal mean of the NINO3.4 sea surface temperature (SST) anomalies is greater/less than the typical seasonal mean by 0.5°C. The overall results of this study support that ENSO does not affect the landfalling TCs in Korea; the mean frequencies of the TC landfalls (influences) during El Niño and La Niña calculated over the entire analysis period are 1.1 (3.3) and 1.2 (3.0), respectively. The variations in the basin-wide distribution of TCs show that the influence of ENSO on TC distribution is extended over southeastern Japan with no significant signals coming from over the Korean Peninsula and the East China Sea. The change in the intensity of the landfalling TCs in the Korean Peninsula due to ENSO leads to the same conclusion as that in the frequency of the landfalling TCs. In addition, the same conclusion is obtained when the TC season duration is expanded to include the entire year and when different definitions of the ENSO years (e.g., based on the preceding or following winter NINO3.4 SST anomalies) are selected for analysis. 相似文献
5.
Bases on the NCEP/NCAR reanalysis products, Had ISST dataset, and data of tropical cyclone(TC)landfalling in the Chinese mainland during 1960-2019, the possible impacts of Indian Ocean Dipole(IOD) mode and Indian Ocean basin(IOB) mode on the last-TC-landfall date(LLD) and first-TC-landfall date(FLD), respectively, are investigated in this study. The LLD is in significantly negative correlation with autumn IOD on the interannual timescale and their association is independent of El Nino-Southern O... 相似文献
6.
Interannual and Decadal Variability of Landfalling Tropical Cyclones in the Southeast Coastal States of the United States 总被引：2，自引：0，他引：2
The interannual variability of the Atlantic tropical cyclone(TC)frequency is well known.Separately,recent studies have also suggested that a much longer,multidecadal(40-60 year)trend might be emerging from the recent increase in Atlantic TC activity.However,the overall structure of the intrinsic frequencies(or temporal modes)of Atlantic TC activity is not yet known.The focus of this study is to systematically analyze the intrinsic frequencies of Atlantic TC activity using hurricane and tropical storm landfall data collected along the southeast coast(SEC)of the United States.Based on an Empirical Mode Decomposition (EMD) analysis of the frequency of landfall TCs along the SEC from 188701999,we have found that Atlantic TC activity has four primary,temporal modes.The interannual and multidecadal modes reported in the published literature are two such modes.After identifying all primary modes,the relative importance of each mode and its physical cause can be analyzed.For example,the most energetic mode is the interannual mode(2-7 year period).This mode is known to be associated with the 2-7 year El Nino/La Nino cycle.The average number of annual landfalling TCs along the SEC decreased by 24% during El Nino years,but did not show significant increase during weak and moderate La Nina years.However,intense La Nina years were generally associated with more than average landfalling TCs along the SEC.The effects of El Nino and La Nina also became more significant when only hurricanes were considered.The significance of the effects of El Nino and La Nina on landfalling TCs and hurricanes in different US southeast coastal states showed significant differences. 相似文献
7.
地球系统模式已经逐步成为研究热带气旋（TC）活动气候变化的重要工具之一,之前的研究发现南京信息工程大学地球系统模式（NESM）高分辨率版本可以较好地模拟全球海温分布及TC活动的气候特征。本研究进一步分析了NESM地球系统模式模拟西北太平洋TC活动的年际变化,并与1967～2016年观测的TC活动进行对比。NESM模式高分辨率版本能够较好地模拟西北太平洋平均海温及与ENSO事件联系的海温异常变化特点,对El Ni?o事件发生时西北太平洋TC的生成频数和路径分布的模拟较好,也能模拟El Ni?o年TC生成位置比La Ni?a年偏东的特征,但是未能模拟出TC平均生命周期和Ni?o3.4地区海温的相关性。并且模式模拟的La Ni?a年TC的生成位置偏东,主要原因是模拟La Ni?a年季风槽平均位置偏东。研究结果有助于进一步改进NESM模式和利用NESM模式研究TC活动。 相似文献
8.
登陆福建的热带气旋对广东降水的影响 总被引：22，自引：21，他引：1
普查1970~2005年登陆福建省的热带气旋(TC)资料可知:(1)36年间平均每年有1.4个TC登陆福建省,其中以强热带风暴及以上级别为主;6~10月都有TC登陆福建省,7~9月尤其8月份是登陆的高峰期;登陆福建的TC具有明显的年际变化。(2)登陆福建省的TC主要集中于3种路径:偏北、偏西、西北型路径,其中偏北、偏西型路径以登陆闽中、闽南为主,而西北型路径有一半登陆闽中,登陆闽北以及闽南的几率相当。(3)偏西型路径的TC登陆后仍以偏西或西南的路径移动,一般有西南季风的配合,80%对广东有显著影响;西北型路径的TC登陆闽北时由于继续以西北或偏北路径移动且在广东上空没有强劲的西南季风的配合,则对广东基本无影响,登陆闽中南的TC登陆后移向偏西或西南,或者有强劲的西南季风的配合对广东造成显著影响的占47.8%,而减弱快同时没有西南季风配合的形势则对广东的影响不显著。 相似文献
9.
近65年ENSO事件强度变化及时频特征研究 总被引：6，自引：2，他引：6
利用海洋尼诺指数(ONI)、南方涛动指数(SOI)和多变量ENSO指数(MEI)等ENSO特征值分析了1951年1月—2016年5月近65年ENSO事件的强度与时频特征,并将其强度划分为5个等级。结果表明:近65年共发生22次暖事件（El Ni?o）和13次冷事件（La Ni?a）;对ENSO特征值进行频次分析发现,强El Ni?o月份所占比例比强La Ni?a多;使用连续小波、交叉小波和小波相干分析得出,ENSO循环主要具有2~7 a的周期,还具有10~16 a的年代际变化。 相似文献
10.
Kyung-Ja Ha Soon-Jo Yoon Kyung-Sook Yun Jong-Seong Kug Yeon-Soo Jang Johnny C. L. Chan 《Theoretical and Applied Climatology》2012,109(3-4):383-395
The effects of the El Ni?o-Southern Oscillation (ENSO) phase and the shifting of the ENSO sea surface temperature (SST) on the intensity of tropical cyclones (TC) have been extensively investigated in terms of TC genesis locations in the western North Pacific (WNP). To advance the hypothesis for a relation of genesis location–intensity that the TC formation location hints its intensity, two cases have been compared, which include the phase of the decaying El Ni?o turning over to La Ni?a (type I) and the phase that recovers to a neutral condition (type II). In addition, the shift of ENSO SST to the central Pacific warming (CPW) from the East Pacific warming (EPW) has been examined. The genesis potential index (GPI) and the accumulated cyclone energy have been applied to compare the differences between the ENSO phase and the TC formation location. It was apparent that ENSO influences the WNP typhoon formation location depending on the cycle of the ENSO phase. In addition, the typhoon activity was affected by the zonal shift of the El Ni?o SST. The CPW, which has maximum SST over the central Pacific, tends to have a persistently high GPI over the WNP in September–November and June–August, demonstrating that the formation locations of strong TCs significantly shift southeastward compared with the EPW having SST maximum over the eastern Pacific. CPW years revealed a distinguishable relationship between the TC formation location and the TC between the tropical depression (TD) + tropical storm (TS) and the intense typhoon of category 4?+?5. 相似文献
11.
An Examination of ENSO’s Effect on the Monthly and Seasonal Climate of Hong Kong from a Statistical Perspective 总被引：1，自引：0，他引：1 
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下载免费PDF全文 This study aims to examine the effect of El Nino and La Nina on the monthly and seasonal climate of Hong Kong against the ENSO-neutral situation from a statistical perspective. Monthly and seasonal temperature and rainfall of Hong Kong and monthly number of tropical cyclones (TCs) coming within 500 km of the city over the 59-yr (1950-2008) period are examined under three ENSO situations, namely El Nino, La Nina, and ENSO-neutral. It is found that, compared with the ENSO-neutral situation, El Nino tends... 相似文献
12.
In this paper, the impact of ENSO on the precipitation over China in the winter half-year is investigated diagnostically. The results show that positive precipitation anomalies with statistical significance appear over southern China in El Nio episodes, which are caused by the enhanced warm and humid southwesterlies along the East Asian coast in the lower troposphere. The enhanced southwesterlies transport more water vapor to southern China, and the convergence of water vapor over southern China increases the precipitable water and specific humidity. In La Nia episodes,although atmospheric elements change reversely, they are not statistically significant as those in El Nio periods. The possible physical mechanism of the different impact of ENSO cycle on the precipitation over southern China is investigated by analyzing the intraseasonal oscillations(ISOs) in El Nio and La Nia winter half-years, respectively. By comparing the characteristics of ISOs in El Nio and La Nia, a physical mechanism is proposed to explain the different responses of the precipitation over China to ENSO in the winter half-year. In El Nio episodes, over western North Pacific(WNP) and South China Sea(SCS) the ISOs are inactive and exert little effect on water vapor transport and convergence, inducing positive precipitation anomalies with statistical significance over southern China in El Nio episodes. In La Nia episodes, however, the ISOs are active, which weaken the interannual variation signals of ENSO over WNP and southern China and lead to the insignificance of the interannual signals related to ENSO. Therefore, the different responses of precipitation over China to ENSO in the winter half-year are possibly caused by the difference of intraseasonal oscillations over WNP and SCS between El Nio and La Nia. 相似文献
13.
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
14.
A high-resolution (T213) coupled ocean–atmosphere general circulation model (CGCM) has been used to examine the relationship between El Niño/Southern Oscillation (ENSO) and tropical cyclone (TC) activity over the western North Pacific (WNP). The model simulates ENSO-like events similar to those observed, though the amplitude of the simulated Niño34 sea surface temperature (SST) anomaly is twice as large as observed. In El Niño (La Niña) years, the annual number of model TCs in the southeast quadrant of the WNP increases (decreases), while it decreases (increases) in the northwest quadrant. In spite of the significant difference in the mean genesis location of model TCs between El Niño and La Niña years, however, there is no significant simultaneous correlation between the annual number of model TCs over the entire WNP and model Niño34 SST anomalies. The annual number of model TCs, however, tends to decrease in the years following El Niño, relating to the development of anticyclonic circulation around the Philippine Sea in response to the SST anomalies in the central and eastern equatorial Pacific. Furthermore, it seems that the number of model TCs tends to increase in the years before El Niño. It is also shown that the number of TCs moving into the East Asia is fewer in October of El Niño years than La Niña years, related to the anomalous southward shift of mid-latitude westerlies, though no impact of ENSO on TC tracks is found in other months. It is found that model TCs have longer lifetimes due to the southeastward shift of mean TC genesis location in El Niño years than in La Niña years. As the result of longer fetch of TCs over warm SST, model TCs appear to be more intense in El Niño years. These relationships between ENSO and TC activity in the WNP are in good agreement with observational evidence, suggesting that a finer-resolution CGCM may become a powerful tool for understanding interannual variability of TC activity. 相似文献
15.
热带气旋每年对我国东南沿海地区造成很大的经济损失和人员伤亡。为了解登陆中国热带气旋的强度、位置和生成频率等特征,基于1949—2018年西北太平洋热带气旋数据,采用分位数回归的方法分析了登陆中国热带气旋活动年际变化特征规律。结果发现:登陆中国热带气旋活动年际变化特征受ENSO事件的影响,El Ni?o年、La Ni?a年和正常年登陆中国热带气旋的最大风速、最长生命期和生成位置的年际变化规律存在较大差异,且这种差异程度和热带气旋强度有关;此外,在不同的分位数下登陆中国热带气旋活动特征的年际变化趋势系数并不相同。研究结果可以为我国的东南沿海热带气旋数据分析和趋势预测提供有效的参考。 相似文献
16.
ENSO对中国冬半年降水影响的不对称性及机制分析 总被引：2，自引：4，他引：2
利用1979—2010年观测和再分析资料,诊断分析ENSO对中国华南冬半年降水的影响及其机制。结果表明,在El Ni?o冬半年期间,东亚沿岸上空对流层低层南风的增强导致了水汽输送明显偏多,水汽在华南辐合,使得大气可降水量和比湿增加,降水显著偏多。而在La Ni?a冬半年期间,这些大气要素并没有呈现显著的相反变化,负异常的量值很弱并在统计上不显著。通过进一步分析El Ni?o和La Ni?a冬半年期间季节内振荡的特点,给出一种华南冬半年降水对ENSO信号不对称响应的物理解释。El Ni?o期间,热带西太平洋到南海地区的季节内振荡不活跃,与El Ni?o相联系的西北太平洋反气旋性环流异常造成的水汽输送以及水汽辐合在华南能够稳定维持,致使华南降水明显偏多。但在La Ni?a冬半年期间,季节内振荡很活跃,与La Ni?a相联系的西北太平洋气旋性环流异常受到季节内时间尺度的扰动影响,ENSO的年际变化信号被季节内振荡破坏,使得西北太平洋和华南的年际异常信号不能得到稳定维持,导致与ENSO信号相联系的年际变化在统计上不显著。因此,热带西太平洋到南海地区的季节内振荡强度在El Ni?o和La Ni?a冬半年期间的差异,是华南冬半年降水对ENSO信号不对称响应的一个主要原因。 相似文献
17.
使用NCEP/NCAR再分析资料、中国气象局台站降水资料和GPCC降水资料,系统研究了在冬季平流层准两年振荡(Quasi-Biennial Oscillation, QBO)调制下,厄尔尼诺-南方涛动(El Ni?o-Southern Oscillation, ENSO)不同阶段与中国夏季降水的可能联系。根据两者的位相和强度,可将它们的配置分为QBO西风/El Ni?o、QBO西风/La Ni?a、QBO东风/El Ni?o、QBO东风/La Ni?a。研究结果表明,在年际时间尺度上,ENSO和QBO无显著相关关系。冬季QBO西风位相时,El Ni?o发展年夏季,我国整体偏旱,而华南偏涝;衰减年夏季,华南、华东北部偏旱,东北、长江流域偏涝。La Ni?a发展年夏季,我国东部降水异常呈负-正-负的三极分布;衰减年夏季,东南沿海偏涝。冬季QBO东风位相时,El Ni?o发展年夏季,长江以北偏旱;衰减年夏季,我国东部降水异常呈负-正-负的三极分布。La Ni?a发展年夏季,江淮和华南南部偏旱;衰减年夏季,我国东部沿海偏涝。ENSO是影响我国夏季降水异常的重要因子,而QBO的调制作用在ENSO衰减年夏季更为显著。相比冬季QBO东(西)风位相,QBO西(东)风位相时El Ni?o (La Ni?a)期间赤道西太平洋负(正)海温异常更强,衰减年夏季位于西太平洋的异常下沉(上升)运动和印度洋的异常上升(下沉)运动更强更深厚,西太平洋副热带高压范围更大(小),南亚高压更偏东(西)。 相似文献
18.
The locations(longitudes and latitudes)of the tropical cyclones(TCs)making landfall on the Chinese mainland from 1949 to 2008 are investigated in detail by using ArcGis and FORTRAN routine.The southeast coastline[110 to 122°E)with most landfall TCs was selected as the key region,which was divided into 12 subsections with 1°intervals of longitude.The study period was from July to September in each year.The result showed that the average sustaining time of TCs making landfall on the subsections east of 118°E is longer than those west of 118°E.Before landfall,the averaged TC intensity in the subsections east of118°E is stronger than that west of it.After landfall,however,the difference between the west and east is not significant.The index of destructive potential for the period before/after landfall was defined as TDP1/TDP2.The maximum of TDP1/TDP2 occurred in the subsection of[119,120°E)/[110,111°E).The ENSO impact on the frequency and average location of landfall TC over the whole region at 110 to 122°E is not obvious,but the effect varies with specific subsections.There is little differences of averaged TDP1 in the subsections between different phases of ENSO events,but the averaged TDP2 is larger in the warm events than that in the cold events.The rainstorm days of each station caused by TCs in different subsections were counted respectively.The results suggested that the rainstorm days of the subsections east of 118°E are much more than those west of 118°E.The larger values are primarily distributed at the subsections of[119,120°E)and[110,111°E). 相似文献
19.
印度洋海盆增暖及ENSO对西北太平洋热带气旋活动的影响 总被引：2，自引：1，他引：1
本文主要分析1950～2010年间印度洋海盆增暖和西北太平洋热带气旋(TC)活动的关系, 并与ENSO对西北太平洋TC活动的影响相比较, 结果表明:印度洋海盆异常增暖与西北太平洋地区总TC生成年频数尤其是弱TC相关较好, 印度洋海盆异常增暖, 西北太平洋地区为异常的反气旋, 对流抑制, 降水偏少, 不利于TC的生成, 反之亦然。而ENSO对西北太平洋热带气旋的影响, 主要体现在对强TC的年生成频数的影响, El Ni?o 发展年, 季风槽加深东伸, TC生成位置偏东, 由于TC在海洋上的生命史较长, TC的平均强度偏强, 因而强TC年生成频数偏多;La Ni?a发展年, 季风槽较浅, TC生成位置偏西, TC的平均强度偏弱, 强TC年生成频数偏少。但是ENSO指数与强TC年频数的相关有着年代际的变化, 在1950～1969年和1990～2009年间, ENSO指数和强TC年频数相关很好, 分别为0.532和0.687, 而在1970～1989这二十年间, 两者相关很弱, 只有0.081。 相似文献
20.
登陆中国大陆不同区间的热带气旋特征初步分析 总被引：3，自引：1，他引：2
利用地理信息系统及程序计算得到了1949—2008年登陆中国大陆的热带气旋(TC)登陆点经纬度信息,在此基础上对登陆中国大陆的TC进行分析,最终选择110～122°E海岸线为研究区域,7—9月为研究时段,且将110～122°E海岸线以1°E为间隔划分为12段,分析这12段海岸线登陆TC的基本特征发现:118°E以东的区间TC登陆前后平均维持时间及登陆前平均强度基本上为大于118°E以西的区间,登陆后平均强度东西两段相差不大;定义了TC登陆前(后)破坏潜力指数TDP1(TDP2),TDP1(TDP2)最大值出现在区间[119,120°E)([110,111°E));ENSO事件对7—9月登陆110～122°E段的TC频数、平均登陆点位置影响并不明显,对各区间登陆TC的影响也不尽相同;各区间平均TDP1冷暖事件年对比差别较大,平均TDP2在暖事件年基本上比冷事件年大;1961—2008年,各区间对应的暴雨总站次,118°E以东的区间要远大于以西的区间,就空间分布而言,较大值的分布出现在区间[119,120°E),[110,111°E)。 相似文献