热带气旋强度影响其移动的物理机制

应用无基本气流的无辐射正压模式研究热带气旋强度影响其移动的物理机制，结果表明，（１）弱（强）热带气旋的大度尺β涡旋弱（强）通风气流速度小（大），因而其移速慢（快）（２）弱的与强的热带气旋的大尺度β涡旋的方位位相之差，通风气流方向之差都很小，因此其移向的差别也很小；（３）热带气旋移速振荡和移向摆动的周期与小尺度涡旋活动的周期相接近，在热带气旋内部区域；弱（强）热带气旋的切向风速小（大），小尺度涡旋活     

环境气流及非绝热加热对热带气旋结构和移动的影响

设计一个三层的准地转斜压模式,研究了不同结构环境气流和环境非绝热加热场中热带气旋移动路径和结构的特征.数值试验的结果表明:(1)无外界影响下热带气旋向西北方向移动,垂直速度场有明显的螺旋结构;(2)热带气旋主要受基本环境气流引导,非对称环流中的小扰动干扰了热带气旋的移动;(3)非绝热加热场对热带气旋影响较大,热带气旋有向加热中心移动的倾向,同时热带气旋的水平、垂直结构都有较大的变化.     

内核及外围尺度与热带气旋强度关系的初步研究

基于日本气象厅（JMA）区域谱模式（RSM）20 km分辨率的再分析资料,计算并统计了2001—2007年西北太平洋热带气旋逐6小时（共2 174个样本）的内核及外围尺度特征,初步分析了内核及外围尺度分别与热带气旋强度变化的关系。结果表明,外围尺度的增大（减小）有利于热带气旋的增强（减弱）;内核区较大（最大风速半径大于120 km）时,内核区的收缩（放大）有利于热带气旋的增强（减弱）;对于较小（最大风速半径不足120 km）内核区的热带气旋,其内核区的收缩（放大）反而易使热带气旋减弱（增强）。      

2009—2015年ECMWF热带气旋集合预报的检验及分析

本文从四个方面检验分析了ECMWF 2009—2015年西北太平洋热带气旋集合平均预报性能。结果表明：集合预报对路径的预测能力逐年提高,对强度预报整体偏弱。随着热带气旋强度增强,集合预报对移速和移向的预测能力提高,而移向预报偏左、移速预报偏慢、强度预测偏弱的现象较明显。将影响热带气旋的引导气流分为偏强、中等、偏弱三类,引导气流偏弱时热带气旋移动偏慢,因此移向预报的不确定性大;而引导气流偏强时热带气旋移向明确,只是移速预报不稳定。进入南海的三类路径热带气旋,集合预报对西行、西北行两类的移速、移向预报效果较好,而西行后北折的预报较差,在热带气旋北折前,移向预报发散度很大,向北转折后移向趋于稳定,移速预报的误差相对较大。这几种情形的检验结果,在热带气旋集合预报的业务应用中值得注意。     

基于OLR的热带气旋移向预报方法研究

运用GMS-5气象卫星的OLR资料,研究了2001～2002年6月10日～8月10日西北太平洋上15个热带气旋的移动方向。选取多个OLR特征值因子及热带气旋中心最低海平面气压,结合《热带气旋年鉴》资料,采用统计回归的方法,得到热带气旋未来6、12、24小时移向的客观预报算式,其结果与年鉴中移向之间的复相关系数分别达到0．954、0．945、0．914。用预留的2001年6号台风作检验,结果很好。该方法可在日常的业务预报中试用,有助于提高热带气旋移向的预报水平,尤其是对移向突变的热带气旋具有较强的预报能力。     

斜压涡旋中的通风气流与热带气旋移动的关系

应用准地转斜压模式数值模拟了热带气旋的移动。将热带气旋的流场分解为轴对称分量和非对称分量，研究非对称流场中的通风气流矢量与热带气旋移动矢量的关系。数值试验结果表明：（１）在热带气旋的非对称流场中，不但有大尺度β涡旋，而且还有小尺度涡旋。（２）小尺度涡旋与大尺度β涡旋之间的相互作用导致热带气旋移向的摆动和移速的振荡。（３）应用Ｆｉｏｒｉｎｏ和Ｅｌｓｂｅｒｒｙ的方法计算的通风气流矢量与热带气旋移动矢量有很大偏差。（４）应用改进的方法计算的通风气流矢量与热带气旋移动矢量相关密切。     

南海北部热带气旋移动路径突然右折的预报研究

南海北部北邻华南沿海,当热带气旋以西或西北路径移至南海北部时突然右折,将很快登陆或严重影响华南地区,此时,如预报稍有失误,就会使整个防台减灾布置工作非常被动,甚至带来生命财产的巨大损失。本文利用８５－９０６－０５－０３攻关资料,对此类热带气旋移动路径突然右折的天气学原因进行研究,结果发现：（１）移向突变前４８～７２小时,在距热带气旋８－１０伟距的西北方位高层（２００ｈＰａ）出现大范围的西到西南气流     

9403号热带气旋综合分析

从天气形势、能量场的角度分析９４０３号热带气旋移动路径发生转向的原因有：（１）冷空气西路南下，阻止热带气旋向西移动；（２）高空槽东移、副高减弱东撤、引导气流发生变化；（３）热带气旋沿高能轴（舌）移动。造成玉林地区出现大暴雨的主要原因是：（１）热带气旋中心从玉林地区经过；（２）出现了典型的北槽南台的形势；（３）偏北、偏东、偏西南气流的强辐合；（４）热带气旋移速慢。     

西北太平洋热带气旋快速增强阶段的风速分布特征

利用联合台风预警中心的最优路径（best-track）资料,筛选出西北太平洋地区快速增强和非快速增强两类热带气旋样本。利用美国国家海洋与大气管理局（NOAA）的多平台热带气旋表面风分析资料,对比分析了两类样本的风速和涡度的分布特征。结果显示,快速增强的热带气旋样本通常结构更紧凑,最大风速较大,最大风速半径较小,台风内区的风速较大。在涡度上表现为快速增强热带气旋样本内区的涡度和涡度梯度较大。对两类样本进行t检验,结果显示两类样本内区的切向风差异明显,说明热带气旋的内区风速分布与其发展之间存在密切联系。其物理机制可能是:当存在较大的内区涡度梯度时,涡度隔离机制有利于对流单体向涡旋中心汇聚,此外较大的涡度意味着较大的惯性稳定度,有利于非绝热加热向热带气旋动能的转换,二者共同作用有利于热带气旋的快速发展。      

基于气候系统模式FGOALS-g2的热带气旋活动及其影响的动力降尺度模拟

热带气旋是气候模拟关注的重要对象,但是,由于当前的气候系统模式分辨率较低,难以合理再现热带气旋分布特征,因此,动力降尺度就成为一种有效的手段。本文使用区域气候模式RegCM3,对中国科学院大气物理研究所气候系统模式FGOALS-g2的模拟结果进行动力降尺度,基于热带气旋路径追踪法,从热带气旋的路径、强度和降水三个方面,检验了动力降尺度在热带气旋模拟能力上的增值。结果表明,动力降尺度结果大幅提升了热带气旋路径频率的模拟,较之全球模式,其与观测的路径频率分布的空间相关系数从0.57提升至0.74;区域模式模拟的热带气旋强度与观测更为一致,全球模式难以模拟40 m s?1以上风速的热带气旋,区域模式能够模拟风速为60 m s?1的热带气旋;在热带气旋降水方面,降尺度后的热带气旋降水贡献率和平均热带气旋降水强度均有所改善,在西北太平洋区域较之全球模式,区域模式将热带气旋降水贡献率和降水强度提高了10%和4.7 mm d?1。动力降尺度后TC（tropical cyclone）的模拟技巧得到提升的区域为西北太平洋区域,但在中国南海区域,技巧提升的不显著甚至有所下降。关于动力降尺度结果在西北太平洋区域的技巧提升,分析表明能够更好体现CISK（Conditional Instability of the Second Kind）机制是主要原因,区域模式模拟的水汽增多、正涡度增强、上升运动增强而垂直风切变减弱都有显著贡献。     

COMPARATIVE ANALYSIS OF VARIOUS DATA OF AIR–SEA TEMPERATURE DIFFERENCE AND ITS VARIATION ACROSS SOUTH CHINA SEA IN THE PAST 35 YEARS

Using the International Comprehensive Ocean-Atmosphere Data Set(ICOADS) and ERA-Interim data, spatial distributions of air-sea temperature difference(ASTD) in the South China Sea(SCS) for the past 35 years are compared,and variations of spatial and temporal distributions of ASTD in this region are addressed using empirical orthogonal function decomposition and wavelet analysis methods. The results indicate that both ICOADS and ERA-Interim data can reflect actual distribution characteristics of ASTD in the SCS, but values of ASTD from the ERA-Interim data are smaller than those of the ICOADS data in the same region. In addition, the ASTD characteristics from the ERA-Interim data are not obvious inshore. A seesaw-type, north-south distribution of ASTD is dominant in the SCS; i.e., a positive peak in the south is associated with a negative peak in the north in November, and a negative peak in the south is accompanied by a positive peak in the north during April and May. Interannual ASTD variations in summer or autumn are decreasing. There is a seesaw-type distribution of ASTD between Beibu Bay and most of the SCS in summer, and the center of large values is in the Nansha Islands area in autumn. The ASTD in the SCS has a strong quasi-3a oscillation period in all seasons, and a quasi-11 a period in winter and spring. The ASTD is positively correlated with the Nio3.4 index in summer and autumn but negatively correlated in spring and winter.     

Could the Recent Taal Volcano Eruption Trigger an El Ni?o and Lead to Eurasian Warming?

<正>The Taal Volcano in Luzon is one of the most active and dangerous volcanoes of the Philippines. A recent eruption occurred on 12 January 2020(Fig. 1a), and this volcano is still active with the occurrence of volcanic earthquakes. The eruption has become a deep concern worldwide, not only for its damage on local society, but also for potential hazardous consequences on the Earth’s climate and environment.     

VARIABILITY OF INTER-ANNUAL RELATIONSHIP BETWEEN INDIAN OCEAN DIPOLE AND HUAXI REGION’S AUTUMN PRECIPITATION

The moving-window correlation analysis was applied to investigate the relationship between autumn Indian Ocean Dipole (IOD) events and the synchronous autumn precipitation in Huaxi region, based on the daily precipitation, sea surface temperature (SST) and atmospheric circulation data from 1960 to 2012. The correlation curves of IOD and the early modulation of Huaxi region’s autumn precipitation indicated a mutational site appeared in the 1970s. During 1960 to 1979, when the IOD was in positive phase in autumn, the circulations changed from a “W” shape to an ”M” shape at 500 hPa in Asia middle-high latitude region. Cold flux got into the Sichuan province with Northwest flow, the positive anomaly of the water vapor flux transported from Western Pacific to Huaxi region strengthened, caused precipitation increase in east Huaxi region. During 1980 to 1999, when the IOD in autumn was positive phase, the atmospheric circulation presented a “W” shape at 500 hPa, the positive anomaly of the water vapor flux transported from Bay of Bengal to Huaxi region strengthened, caused precipitation ascend in west Huaxi region. In summary, the Indian Ocean changed from cold phase to warm phase since the 1970s, caused the instability of the inter-annual relationship between the IOD and the autumn rainfall in Huaxi region.     

IMPACT OF ATMOSPHERIC LOW-FREQUENCY OSCILLATION ON THE IMMIGRATION OF NILAPARVATA LUGENS(STL) IN HUNAN AND JIANGXI PROVINCES

Various features of the atmospheric environment affect the number of migratory insects, besides their initial population. However, little is known about the impact of atmospheric low-frequency oscillation(10 to 90 days) on insect migration. A case study was conducted to ascertain the influence of low-frequency atmospheric oscillation on the immigration of brown planthopper, Nilaparvata lugens(Stl), in Hunan and Jiangxi provinces. The results showed the following:(1) The number of immigrating N. lugens from April to June of 2007 through 2016 mainly exhibited a periodic oscillation of 10 to 20 days.(2) The 10-20 d low-frequency number of immigrating N. lugens was significantly correlated with a low-frequency wind field and a geopotential height field at 850 h Pa.(3) During the peak phase of immigration, southwest or south winds served as a driving force and carried N. lugens populations northward, and when in the back of the trough and the front of the ridge, the downward airflow created a favorable condition for N. lugens to land in the study area. In conclusion, the northward migration of N. lugens was influenced by a low-frequency atmospheric circulation based on the analysis of dynamics. This study was the first research connecting atmospheric low-frequency oscillation to insect migration.     

A COMPARATIVE ANALYSIS OF ATMOSPHERIC AND OCEANIC CONDITIONS BEFORE THE OCCURRENCE OF TWO TYPES OF EL NIO EVENTS

The atmospheric and oceanic conditions before the onset of EP El Ni?o and CP El Ni?o in nearly 30 years are compared and analyzed by using 850 hPa wind, 20℃ isotherm depth, sea surface temperature and the Wheeler and Hendon index. The results are as follows: In the western equatorial Pacific, the occurrence of the anomalously strong westerly winds of the EP El Ni?o is earlier than that of the CP El Ni?o. Its intensity is far stronger than that of the CP El Ni?o. Two months before the El Ni?o, the anomaly westerly winds of the EP El Ni?o have extended to the eastern Pacific region, while the westerly wind anomaly of the CP El Ni?o can only extend to the west of the dateline three months before the El Ni?o and later stay there. Unlike the EP El Ni?o, the CP El Ni?o is always associated with easterly wind anomaly in the eastern equatorial Pacific before its onset. The thermocline depth anomaly of the EP El Ni?o can significantly move eastward and deepen. In addition, we also find that the evolution of thermocline is ahead of the development of the sea surface temperature for the EP El Ni?o. The strong MJO activity of the EP El Ni?o in the western and central Pacific is earlier than that of the CP El Ni?o. Measured by the standard deviation of the zonal wind square, the intensity of MJO activity of the EP El Ni?o is significantly greater than that of the CP El Ni?o before the onset of El Ni?o.     

全球贸易隐含碳变化及其影响分析

基于最新的GTAP8 (Global Trade Analysis Project）数据库,使用投入产出法,分析了2004年到2007年全球贸易变化下南北集团贸易隐含碳变化及对全球碳排放的影响。结果显示,随着发展中国家进出口规模扩张,全球贸易隐含碳流向的重心逐渐向发展中国家转移。2004年到2007年,发达国家高端设备制造业和服务业出口以及发展中国家资源、能源密集型行业及中低端制造业出口的趋势加强,该过程的生产转移导致全球碳排放增长4.15亿t,占研究时段全球贸易隐含碳增量的63%。未来发展中国家的出口隐含碳比重还将进一步提高。贸易变化带来的南北集团隐含碳流动变化对全球应对气候变化行动的影响日益突出,发达国家对此负有重要责任。     

Analysis of Atmospheric Boundary Layer Height Characteristics over the Arctic Ocean Using the Aircraft and GPS Soundings

正ERRATUM to: Atmospheric and Oceanic Science Letters, 4(2011), 124-130 On page 126 of the printed edition (Issue 2, Volume 4), Fig. 2 was a wrong figure because the contact author made mistake giving the wrong one. The corrected edition has been updated on our website. The editorial office is sincerely sorry for any     

Index to Vol.31

正AN Junling;see LI Ying et al.;(5),1221—1232AN Junling;see QU Yu et al.;(4),787-800AN Junling;see WANG Feng et al.;(6),1331-1342Ania POLOMSKA-HARLICK;see Jieshun ZHU et al.;(4),743-754Baek-Min KIM;see Seong-Joong KIM et al.;(4),863-878BAI Tao;see LI Gang et al.;(1),66-84BAO Qing;see YANG Jing et al.;(5),1147—1156BEI Naifang;     

Information for Contributors

正Journal of Meteorological Research is an international academic journal in atmospheric sciences edited and published by Acta Meteorologica Sinica Press,sponsored by the Chinese Meteorological Society.It has been acting as a bridge of academic exchange between Chinese and foreign meteorologists and aiming at introduction of the current advancements in atmospheric sciences in China.The journal columns include Articles.Note and Correspondence,and research letters.Contributions from all over the world are welcome.