THE INTENSITY VARIATION OF THE SUMMER INTERTROPICAL CONVERGENCE ZONE IN WESTERN NORTH PACIFIC AND ITS IMPACT ON TROPICAL CYCLONES

Based on the satellite data from the National Oceanic and Atmospheric Administration and the NCEP/NCAR reanalysis data, the variation of the intensity of convection over the Intertropical Convergence Zone(ITCZ) in summer and its impacts on tropical cyclones are studied. In this paper, an intensity index of the ITCZ is proposed according to Outgoing Longwave Radiation(OLR) in the region of(5°–20°N, 120°–150°E) in the western North Pacific(WNP). Then strong and weak ITCZ years are classified and different variables during the strong/weak ITCZ years are analyzed. The composite results show that the ITCZ anomaly is connected to the general atmospheric circulation and SST distribution. In the strong ITCZ years, the subtropical anticyclone weakens and shifts northward. Besides, there is salient cyclonic anomaly at the low level and anticyclonic anomaly at the high level. SST patterns in the preceding winter resemble to those of La Nina. It could persist into the succeeding summer. However, it is opposite in the weak ITCZ years. The impact of the ITCZ anomaly on the tropical cyclone(TC) formation and track is also discussed. There are more TCs over the WNP(5°–20°N, 120°–150°E) in the strong ITCZ years and there is a significant increase in the northward recurving TCs. In the weak ITCZ years, fewer TCs occur and the frequency of the northwestward track is higher.     

ITCZ的季节内振荡及其与热带气旋发生阶段性的关系

利用中国气象局提供的热带气旋资料和NCEP/NCAR再分析等资料, 研究了热带辐合带(Intertropical Convergence Zone, 简称ITCZ)上对流强度的季节内振荡特征及其与热带气旋生成频数阶段性变化的关系, 并进一步研究了它与越赤道气流、 赤道西风和ITCZ北侧偏东风季节内振荡的关系。研究发现: (1) ITCZ对流强度的变化有明显的30～60 d振荡, 西太平洋 (5°N～20°N, 120°E～150°E) 范围内的热带气旋约有2/3发生在30～60 d振荡的活跃位相。(2) ITCZ季节内振荡在热带地区表现为向东传播的特征, 而在副热带地区 (25°N～35°N) 表现出清晰的西传特征。在ITCZ季节内振荡较强年, 振荡在由赤道传播至15°N左右时, 与北面向南传播的振荡在该纬度附近汇合, 对流强度增强, 使热带气旋在此期间频繁发生。而在弱年, 振荡由赤道一直向北传播至30°N附近, 15°N附近的ITCZ对流较弱, 热带气旋生成偏少。(3) 赤道西风、105°E～110°E越赤道气流和ITCZ北侧的偏东风气流本身也存在30～60 d振荡。这三支气流的30～60 d振荡与ITCZ的季节内强弱变化密切相关。然而, 相比之下偏东风气流的30～60 d振荡和ITCZ对流强弱的30～60 d振荡对应关系略差。     

60年来西北太平洋上不同强度热带气旋的变化特征

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.     

REGIONAL DISCREPANCIES OF THE IMPACT OF TROPICAL INDIAN OCEAN WARMING ON NORTHWEST PACIFIC TROPICAL CYCLONE FREQUENCY IN THE YEARS OF DECAYING EL NIO

This study investigates the influences of tropical Indian Ocean(TIO) warming on tropical cyclone(TC)genesis in different regions of the western North Pacific(WNP) from July to October(JASO) during the decaying El Nio. The results show significant negative TC frequency anomalies localized in the southeastern WNP. Correlation analysis indicates that a warm sea surface temperature anomaly(SSTA) in the TIO strongly suppresses TC genesis south of 21°N and east of 140°E in JASO. Reduced TC genesis over the southeastern WNP results from a weak monsoon trough and divergence and subsidence anomalies associated with an equatorial baroclinic Kelvin wave. Moreover,suppressed convection in response to a cold local SSTA, induced by the increased northeasterly connected by the wind-evaporation-SST positive feedback mechanism, is found unfavorable for TC genesis. Positive TC genesis anomalies are observed over higher latitudinal regions(at around 21°N, 140°E) and the western WNP because of enhanced convection along the northern flank of the WNP anomalous anticyclone and low-level convergence,respectively. Although local modulation(e.g., local SST) could have greater dominance over TC activity at higher latitudes in certain anomalous years(e.g., 1988), a warm TIO SSTA can still suppress TC genesis in lower latitudinal regions of the WNP. A better understanding of the contributions of TIO warming could help improve seasonal TC predictions over different regions of the WNP in years of decaying El Nio.     

1949—2010年西北太平洋热带气旋特征分析

文章分析了1949—2010年发生在西北太平洋上的热带气旋的空间分布特征。并利用趋势分析、小波分析和滑动t检验方法分析了热带气旋的年际变化特征、季节变化特征、周期特征和突变特征。结果表明:西北太平洋热带气旋多生成于5~25°N,110~170°E的海域。频数的年际变化存在三个阶段,月际变化明显,集中出现在7—10月。整个时域上10~15a的波动明显,并经历了三次突变过程。62a间强热带风暴生成最多,台风次之,热带风暴最少。热带气旋强度的年变化不明显。热带气旋强度越强,频数最大值的月份出现越晚。亚洲季风和西太平洋副高对热带气旋的产生起很大的作用。     

Impact of atmospheric and oceanic conditions on the frequency and genesis location of tropical cyclones over the western North Pacific in 2004 and 2010

This study examines the impact of atmospheric and oceanic conditions during May–August of 2004 and 2010 on the frequency and genesis location of tropical cyclones over the western North Pacific. Using the WRF model, four numerical experiments were carried out based on different atmospheric conditions and SST forcing. The numerical experiments indicated that changes in atmospheric and oceanic conditions greatly affect tropical cyclone activity, and the roles of atmospheric conditions are slightly greater than oceanic conditions. Specifically, the total number of tropical cyclones was found to be mostly affected by atmospheric conditions, while the distribution of tropical cyclone genesis locations was mainly related to oceanic conditions, especially the distribution of SST. In 2010, a warmer SST occurred west of 140°E, with a colder SST east of 140°E. On the one hand, the easterly flow was enhanced through the effect of the increase in the zonal SST gradient.The strengthened easterly flow led to an anomalous boundary layer divergence over the region to the east of 140°E, which suppressed the formation of tropical cyclones over this region. On the other hand, the colder SST over the region to the east of 140°E led to a colder low-level air temperature, which resulted in decreased CAPE and static instability energy. The decrease in thermodynamic energy restricted the generation of tropical cyclones over the same region.     

ASYMMETRICAL STRUCTURES OF THE TEMPERATURE AND HUMIDITY OF TROPICAL CYCLONES

Based on NCEP/CFSR 0.5° reanalysis data and the best track data from the Japan Tokyo Typhoon Center,composite and comparative analyses demonstrate the asymmetrical structures of the temperature and humidity in tropical cyclones over the Western North Pacific and the South China Sea from 1979 to 2010.The results are shown as follows.(1) With intensifying tropical cyclones,the flow field tends to become gradually more axisymmetric;however,the asymmetry of the specific humidity in the outer regions is more obvious.(2) In general,tropical cyclones have a non-uniform,vertical, "double warm-core" structure.The "warm-cores" in the lower level of weak tropical cyclones and in the higher level of strong tropical cyclones are the stronger of the two.(3) The distribution area of a "warm-core" is enhanced with cyclone intensification and tends to become more axisymmetric.At 200 hPa,the "warm-core" of a weak cyclone has a weak anticyclone in the center,whereas that of a strong cyclone has a weak cyclone in the center.(4)The "wet-core" of a tropical cyclone is primarily located in the lower level(700-850 hPa).With the cyclone's intensification,the intensity of the "wet-core" increases and the scope of the 0.8 g kg~(-1) specific humidity anomaly tends to expand to higher levels.(5) With the cyclone's deepening,the pseudo-equivalent potential temperature at different levels in different regions increases.In addition,the largest warming rates at each intensity level in the different regions occur in the core area,followed in turn by the envelope and outer areas.     

热带气旋生成指数对印度洋热带气旋频数变化的适用性研究

本文利用ERA5 1979-2019年逐月大气再分析资料计算南北印度洋热带气旋生成指数，并和IBTrACS观测数据进行比较，探讨用热带气旋生成指数研究南北印度洋热带气旋变化特征的适用性.研究发现热带气旋生成指数能较好地刻画南北印度洋热带气旋的空间分布特征、北印度洋热带气旋个数月变化的双峰结构，以及南印度洋比北印度洋热带气旋发生概率高等特征.最新的IBTrACS v4.0观测资料显示，40年来北印度洋热带气旋每年总生成个数平均每10年增加1.3个，频数的增加主要来源于热带低压和热带风暴，而南印度洋热带气旋每年总生成个数每10年减少2.8个.热带气旋生成指数能很好地描述北印度洋热带气旋生成个数的上升趋势，但对南印度洋热带气旋生成个数趋势的刻画与观测不一致，可能原因需要进一步深入研究.     

Variations in extratropical cyclone activity in northern East Asia

Based on an improved objective cyclone detection and tracking algorithm, decadal variations in extratropical cyclones in northern East Asia are studied by using the ECMWF 40 Year Reanalysis (ERA-40) sea-level pressure data during 1958-2001. The results reveal that extratropical cyclone activity has displayed clear seasonal, interannual, and decadal variability in northern East Asia. Spring is the season when cyclones occur most frequently. The spatial distribution of extratropical cyclones shows that cyclon...     

Impact of the Spring SST Gradient between the Tropical Indian Ocean and Western Pacific on Landfalling Tropical Cyclone Frequency in China

The present study identifies a significant influence of the sea surface temperature gradient(SSTG) between the tropical Indian Ocean(TIO; 15°S-15°N, 40°-90°E) and the western Pacific warm pool(WWP; 0°-15°N, 125°-155°E) in boreal spring on tropical cyclone(TC) landfall frequency in mainland China in boreal summer. During the period 1979-2015, a positive spring SSTG induces a zonal inter-basin circulation anomaly with lower-level convergence, mid-tropospheric ascendance and upper-level divergence over the west-central TIO, and the opposite situation over the WWP, which produces lower-level anomalous easterlies and upper-level anomalous westerlies between the TIO and WWP. This zonal circulation anomaly further warms the west-central TIO by driving warm water westward and cools the WWP by inducing local upwelling, which facilitates the persistence of the anomaly until the summer. Consequently, lower-level negative vorticity, strong vertical wind shear and lower-level anticyclonic anomalies prevail over most of the western North Pacific(WNP), which decreases the TC genesis frequency. Meanwhile, there is an anomalous mid-tropospheric anticyclone over the main WNP TC genesis region,meaning a westerly anomaly dominates over coastal regions of mainland China, which is unfavorable for steering TCs to make landfall in mainland China during summer. This implies that the spring SSTG may act as a potential indicator for TC landfall frequency in mainland China.     

南海ITCZ异常变化及其对非移入性南海热带气旋(TC)活动的可能影响

利用美国NOAA提供的向外长波辐射（OLR）资料、NCEP/NCAR再分析资料以及上海台风所提供的热带气旋（TC）资料等,通过定义一个描写南海范围内（5°N~20°N,105°E~120°E）的热带辐合带（Intertropical Convergence Zone,简称ITCZ）强度指数,研究了南海ITCZ年际和年代际异常变化特征及其对非移入性南海TC[South China Sea-generated tropical cyclone（SCS-G TC）]活动的可能影响,并从异常强、弱南海ITCZ年份的大气环流背景和海表温度等变化特征来尝试揭示南海TC的活动规律。结果表明:在年际和年代际时间尺度上,南海ITCZ强度指数与南海TC的生成频数存在显著的负相关关系,长期趋势变化间的关系存在不同。南海ITCZ的强、弱显著地影响到南海TC的生成频数。强南海ITCZ年,南海TC频数偏多;弱南海ITCZ年,南海ITCZ频数偏少。强、弱南海ITCZ年对于南海TC的生成源地、TC的维持时间以及路径和强度的影响不显著。进一步分析表明,动力和环境条件方面,强、弱南海ITCZ年可能差异较大。异常偏强年,对流层低层出现气旋性环流,上层出现反气旋性环流;季风槽在南海区域偏强、位置偏南。与OLR表示的深对流区相配合,存在暖的海表温度和低层强烈的正涡度和强辐合,在高层存在相应的强的气流辐散,形成了极有利于南海TC发生发展的条件。弱南海ITCZ年则相反。另外,ITCZ强年,太平洋异常SST（Sea Surface Temperature）出现为La Ni?a特征,南海ITCZ区对流活跃,强度偏强。反之,ITCZ弱年则表现为El Ni?o特征,南海ITCZ关键区的对流强度偏弱。这些结果可为深刻认识南海TC的生成规律以及对南海TC的预报提供线索。     

Statistical and Comparative Analysis of Tropical Cyclone Activity over the Arabian Sea and Bay of Bengal (1977–2018)

A statistical comparative analysis of tropical cyclone activity over the Arabian Sea and Bay of Bengal (BoB) has been conducted using best-track data and wind radii information from 1977 to 2018 issued by the Joint Typhoon Warning Center. Results have shown that the annual variation in the frequency and duration of tropical cyclones has a significant increasing trend over the Arabian Sea and an insignificant decreasing trend over the BoB. The monthly frequency of tropical cyclones in both the Arabian Sea and the BoB shows a notable bimodal character, with peaks occurring in May and October–November, respectively. The maximum frequency of tropical cyclones occurs in the second peak as a result of the higher moisture content at mid-levels in the autumn. However, the largest proportion of strong cyclones (H1–H5 grades) occurs in the first peak as a result of the higher sea surface temperatures in early summer. Tropical cyclones in the Arabian Sea break out later during the first peak and activity ends earlier during the second peak, in contrast with those in the over BoB. This is related to the onset and drawback times of the southwest monsoon in the two basins. Tropical cyclones in the Arabian Sea are mainly generated in the eastern basin, whereas in the BoB the genesis locations have a meridional (zonal) distribution in May–June (October–November) as a result of the seasonal movement of the low-level positive vorticity belt. The Arabian Sea is dominated by western and northwestern tropical cyclones by that track west and NW, accounting for about 74.6%, whereas the tropical cyclones with a NE track account for only 25.4%. The proportions of the three types of tracks are similar in the BoB, with each accounting for about 33% of the tropical cyclones. The mean intensity and size of tropical cyclones over the Arabian Sea are stronger and larger, respectively, than those over the BoB and the size of tropical cyclones over the North Indian Ocean in early summer is larger than that in autumn. The asymmetrical structure of tropical cyclones over North Indian Ocean is affected by the topography and the longest radius of the 34 kt surface wind often lies in the eastern quadrant of the tropical cyclone circulation in both sea areas. FAN Xiao-ting (樊晓婷), LI Ying (李 英), et al.     

全球变暖对台风活动影响的研究进展

全球变暖是当前热点问题之一,各大洋区时有发生的"超乎寻常"的台风活动也广为关注.全球范围内的台风活动特征是否悄然发生了变化?这种变化与全球变暖是否存在关联?这些问题已成为国际台风界的重点研究内容之一,近年来取得了许多进展.文中从全球台风活动特征变化事实的观测研究,成因分析、数值模拟与预测等方面对此进行了概述.综合各方观点,得到主要共识如下:单个台风的异常活动不宜直接归因于气候变化;全球台风频数的年际变化趋势并不明显;沿海地区人口增长和基础设施增加是近期台风对社会影响加重的主要原因;自1970年以来,一些海区的超强台风比例明显增大,比目前数值模式的模拟结果要大许多;如果全球气候持续变暖,台风的最大风速和降水很可能会继续增加;尽管在台风记录中同时有支持和不支持人类活动(全球变暖的影响)信号存在的证据,但在这一点上还不能给出一致的肯定结论.另外,由于台风和相关气候资料存在均一性方面问题,气候数值模式对台风气候特征描述也存在缺陷,这两类问题的存在使得在目前阶段确切阐明全球变暖和台风活动的关系仍有极大的不确定性.     

南海与西北太平洋地区夏季热带气旋潜在生成指数的改进

现阶段使用的热带气旋潜在生成指数(Genesis Potential Index,GPI)在气候场的空间分布上能很好地拟合热带气旋的生成情况,但在热带气旋的年际变化拟合上效果很差。本研究考虑了相对涡度在热带气旋年际变化拟合上的重要作用,并以此为出发点,尝试改善GPI在西北太平洋地区的拟合效果。基于对1979—2011年美国联合飓风警报中心提供的热带气旋最佳路径数据和NCEP/NCAR再分析资料数据集的研究,将之前GPI中的绝对涡度项替换为修正过的相对涡度项。科氏力项仍然保留;将南海(100°～120°E,5°～25°N)与西北太平洋地区(120°～180°E,5°～40°N)热带气旋生成的差异性也纳入了考量,并在这两个区域分别构建GPI公式,改善了对热带气旋生成的气候分布模拟。除此之外,较之已存的GPI指数,改进后的GPI还很大程度提高了GPI对热带气旋生成年际变化的拟合效果,特别是对弱热带气旋年际变化的拟合效果有了显著提升。     

Analyzing the genesis, intensity, and tracks of western Mediterranean cyclones

Midlatitude cyclones are analyzed on a selected region covering most of southern Europe and the western part of the Mediterranean Sea (35–50°N, 10°W–25°E). On the basis of mean sea level pressure fields of the ECMWF (European Centre for Medium-range Weather Forecast) Reanalysis Dataset (ERA-40), detailed evaluation of Mediterranean cyclones is accomplished for the period between 1957 and 2002 on a 1° horizontal resolution grid. Cyclone centers are identified and their paths are tracked with a 6-h time step (using 00 UTC, 06 UTC, 12 UTC, and 18 UTC). Decadal, annual, and seasonal statistical analysis of cyclone tracks includes the study of the genesis, frequency, and activity of the Mediterranean cyclones as well as the variability of cyclone tracks. The results suggest that the cyclone frequency in the western Mediterranean region increased in summer and autumn, and decreased in winter and spring. A special belt-shaped area is identified, which plays a special role in cyclogenesis, and also, the cyclone tracks often remain within this belt. An overall decreasing trend is detected in winter and spring in the entire Mediterranean belt, while cyclone frequency increased in autumn. The largest positive and negative trend coefficients are identified in summer.     

阿拉伯海热带气旋生成特征分析

利用印度气象局（India Meteorological Department,IMD）、国际气候管理最佳路径档案库（International Best Track Archive for Climate Stewardship,IBTrACS）提供的1982—2020年阿拉伯海热带气旋路径资料,美国国家环境预报中心（National Centers for Environmental Prediction,NCEP）再分析资料,对近39 a阿拉伯海热带气旋源地和路径特征、活跃区域、频数及气旋累积能量（accumulated cyclone energy,ACE）指数的季节特征和年际变化特征进行分析,并结合环境因素,说明其物理成因。结果表明：阿拉伯海热带气旋多发于10°~25°N,65°~75°E海域,5—6月、9—12月发生频数较高且强度较强,1—4月、7—8月发生频数较低且气旋近中心最大风速均小于35 kn;频数的季节变化主要受控于垂直风切变要素;阿拉伯海热带气旋发生频数和ACE近年有上升趋势,年际变化主要受控于海面温度（sea surface temperature,SST）和850 hPa相对湿度要素。     

POSSIBLE INFLUENCE OF FEBRUARY-APRIL ARCTIC OSCILLATION ON THE ITCZ ACTIVITY OF WESTERN-CENTRAL PACIFIC

The daily patterns and activity of Intertropical Convergence Zone(ITCZ) in the Western-Central Pacific Ocean are analyzed using NOAA interpolated Outgoing Longwave Radiation dataset during the period from 1979 to 2008, and the relationships between ITCZ patterns and Arctic Oscillation(AO) is investigated in this paper. In accordance with the central activity region the daily ITCZ can be divided into six patterns—north, south, equator, double, full and weak pattern, respectively. The statistic result shows that the north(accounting for 30.98% of the total observations), south(31.11%) and weak(24.05%) ITCZ patterns are the most active daily patterns within a 30-year period, while the other three ITCZ patterns occur infrequently. Results show that the February-April AO index has a significant positive(negative) correlation with the frequency of the north(weak) ITCZ pattern from March-May to August-October, with the strongest correlation in April-June(March-May). At the same time, the lower tropospheric atmosphere circulation(850-hPa wind field) and SST anomalies corresponding to the AO change significantly in the tropical Pacific. When AO is in the positive phase, there is an anomalous westerly from the equator to 15°N and warmer SST in the critical north ITCZ active region, while there is an anomalous easterly and insignificant change of SST from the equator to 15°S. The wind and SST anomalies share the same characteristics of the equatorial asymmetry and thus enlarge the gradient between the south and north of equator, which would help reinforce convection in the north of equator and result in more frequent occurrence of the northern type of ITCZ.     

The influence of Madden–Julian Oscillation in the genesis of North Indian Ocean tropical cyclones

Cyclonic storms having maximum winds of 34 knots and above that had genesis in north Indian Ocean have been studied with respect to the eastward passage of Madden–Julian Oscillation (MJO). In the three decades (1979–2008), there were a total of 118 cyclones reported in which 96 formed in the region chosen (0–15^oN, 60^oE–100^oE) for the study. Although the percentage of MJO days inducing cyclogenesis is small, it is found that tropical cyclone genesis preferentially occurred during the convective phase of MJO. This accounted for 44 cyclones of the total 54 cyclones (i.e., 81.5%) formed under MJO amplitude 1 and above. The study has shown that, when the enhanced convection of MJO is over the maritime continent and the adjoining eastern Indian Ocean, it creates the highest favorable environment for cyclogenesis in the Bay of Bengal. During this phase, westerlies at 850 hPa are strong in the equatorial region south of Bay of Bengal creating strong cyclonic vorticity in the lower troposphere along with the low vertical wind shear.     

西北太平洋热带气旋潜在生成指数的改进

热带气旋潜在生成指数(GPI,Genesis Potential Index)是热带气旋生成可能性大小的空间分布函数,利用大尺度环境场可以应用于热带气旋活动的季节预报,并且可以评估全球气候变化对热带气旋活动的影响。但是目前的GPI基本都是针对全球热带气旋活动构建的,没有考虑到热带气旋不同活动地区及其内部的差异。本研究考虑到南海和西北太平洋热带气旋生成的不同特点,分别构建了适用于南海(5～25°N,100～120°E)和西北太平洋(5～40°N,120～180°E)的热带气旋GPI。改进后的GPI对南海和西北太平洋区域热带气旋生成具有较好的模拟能力,不仅能很好地模拟南海和西北太平洋热带气旋生成频数空间分布的气候特征(相似系数为0.67),而且能够较好地模拟热带气旋生成在年际时间尺度上的空间分布特征。     

近71a影响黑龙江省热带气旋统计特征分析

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。