巢湖地区一次梅雨期强对流暴雨中尺度特征分析

利用地面气象观测资料、ERA5再分析资料、FY-2E卫星和多普勒雷达资料,对2011年7月17日发生在巢湖地区的一次强对流暴雨过程进行诊断分析。结果显示:500hPa深槽、850hPa切变线及地面低压是此次暴雨过程的天气尺度影响系统,强降水发生在湿层和暖云层深厚、较低的抬升凝结高度、中等强度对流不稳定及弱垂直风切变条件下;FY-2E卫星云图分析表明,此次强降水过程主要是多个中尺度对流系统在巢湖合并所致,短时强降水落区主要落在中尺度对流系统TBB等值线密集区附近,TBB中心强度越强,TBB等值线梯度越大,对应的1h降水量越强;多普勒雷达分析揭示,短时强降水发生在两个对流回波合并期间,对流风暴移动缓慢,大于45dBz强回波均在6km以下,呈低层强烈气旋式辐合、高层辐散特征;地面中尺度辐合线是此次风暴的触发因子;湿位涡诊断结果表明,600hPa以下对流不稳定,600hPa以上对称不稳定,有利于暴雨和中尺度系统的发生发展。     

一次云南强对流暴雨的中尺度特征分析

利用NCEP/NCAR再分析资料及常规观测资料与雷达、卫星等非常规观测资料,综合分析了2014年6月6日云南暴雨过程的天气成因及中尺度对流系统特征。结果表明:500hPa前倾槽、700hPa切变线及地面冷锋是此次暴雨过程的天气尺度影响系统;高能高湿的对流不稳定层结、明显的垂直风向切变是强对流天气形成的有利条件;在Q矢量散度辐合区内多个β中尺度对流系统(MCS)发生发展,短时强降水主要出现在MCS移动方前沿对流活跃的云顶亮温(TBB)等值线密集区,雨强变化与TBB等值线梯度变化密切相关;多普勒雷达及地闪资料显示多个γ中尺度对流系统是强对流暴雨产生的直接影响系统,雷暴易发生于回波强度在35~45dBz、回波顶高超过10km的区域,中尺度辐合线、第二类γ中尺度辐合区附近负地闪密集区与短时强降水、雷暴天气有很好的对应关系。     

东天山哈密地区典型暴雨事件对流触发机制对比分析

本文选取2018年7月31日（简称“7.31”暴雨）和2016年8月8日（简称“8.8”暴雨）两次东天山哈密地区强降水天气过程,利用NCEP/NCAR的FNL资料（0.25°×0.25°）、中国地面卫星雷达三源融合逐小时降水产品、新疆地区常规观测资料、FY-2G卫星产品,通过对暴雨期间锋生函数计算诊断,证实了两次强降水过程中尺度对流系统触发因子差异,取得如下主要结果:（1）“7.31”暴雨期间,500 hPa西太平洋副热带高压位置异常偏北,700 hPa暖舌沿副高南侧偏东急流向西北伸展,低层增暖增湿,暴雨区上空形成不稳定大气层结,多个中尺度对流系统在700 hPa低空急流前生成,向东北方向移动和发展。“8.8”暴雨期间,500 hPa西太平洋副热带高压位置异常偏西,对流云团在对流层低层西南急流前生成向东北方向移动。（2）对流层低层暴雨区暖锋锋生是“7.31”暴雨中尺度对流云团的触发因子,云团初生阶段对流触发主要是锋生水平散度项和由垂直运动发展引起的倾斜项决定,成熟阶段暖锋锋生主要由锋生形变项和倾斜项所致。低空东南急流的维持加强利于锋面次级环流发展,是造成中尺度对流系统长时间维持的主要原因。（3）“8.8”暴雨对流云团由对流层低层弱冷锋触发。对流云团发展初始阶段,对流层低层冷锋锋生主要由水平辐散项决定;对流云团成熟阶段,对流层低层冷锋锋生主要由倾斜项决定。低层切变线长时间维持和加强利于低层冷锋进一步锋生,是造成中尺度对流系统长时间维持的主要原因。     

浙江北部一次短时大暴雨的中尺度分析

利用常规气象观测资料、区域自动站加密观测资料和GFS 0.5°×0.5°逐6h的分析场数据以及多普勒雷达、风云卫星资料,对2013年6月24日浙江北部一次短时大暴雨天气过程的特征及其成因进行了中尺度分析,结果表明:受西太平洋副热带高压西北部边缘的暖湿西南气流和850hPa暖切的共同影响,引发了浙江北部的短时大暴雨天气。在有利的大尺度环境场和物理量场配合下,当低层925hPa的中尺度辐合线和对流层中层700hPa的垂直上升运动区相重合时,中尺度辐合线附近会产生强对流,这对强对流的发生发展具有一定的预报指示意义。此次暴雨过程与中尺度辐合线密切相关,中尺度辐合线是由偏东风和东北风辐合而成,该辐合线先于降水存在,而且从地面一直伸展到对流层中层,之后触发了浙北地区的短时大暴雨天气,强降水区域和强回波带落在中尺度辐合线附近区域。     

陕西北部一次对流性特大暴雨的中尺度分析

利用常规气象资料、FY-2E卫星云图资料、榆林CINRAD/CB雷达资料和NCEP1°×1°再分析资料,对陕西北部绥德县2012年7月15日夜间一次短时特大暴雨过程进行分析,结果表明:高对流有效位能为大暴雨积累了能量条件,850hPa两条湿舌为该次大暴雨的主要水汽来源。850hPa的"人"字型切变和地面中尺度低压加强了暴雨区辐合上升运动,干线过境触发了强对流天气的爆发。强降水时段在卫星云图上表现为2个中尺度对流系统(MCS)合并增强且缓慢移动;雷达回波显示3个对流单体发展较快,后向传播且合并增强为深厚的湿对流风暴,其中一个对流单体有中气旋生成,水平尺度12km,垂直累积液态水含量65kg/m2,并有三体散射现象,强降水开始后,三体散射消失。     

2012-08-13关中西部致灾大暴雨中尺度分析

利用实时资料、自动站加密资料、FY-2C卫星、宝鸡多普勒雷达等资料,对发生于关中西部宝鸡2012-08-13大暴雨天气成因进行分析,重点揭示其中尺度系统特征。结果表明生命史10 h的中尺度对流系统(MCS)是大暴雨的直接原因。而MCS是天气尺度和中尺度系统共同影响造成的:天气尺度东北急流提供大尺度辐合上升运动动力、水汽输送、辐合,从而使关中水汽、稳定度演变为利于对流性降水天气发生,且携带冷空气触发形成MCS,地面中尺度切变线提供带状辐合使对流组织加强。雷达图上,带状、块状强回波对应强降水,当组合反射率因子40 dBz、垂直液态含水量5 kg.m-2、回波顶高9 km时,雨强≥16 mm/h(出现短时暴雨)。     

榆林一次短时突发性暴雨中尺度特征及成因分析

利用NECP 1 °×1 °间隔6 h再分析资料、卫星TBB资料、榆林多普勒雷达以及本地加密观测资料,对2017年7月23日榆林城区短时突发性暴雨成因及中尺度特征进行诊断分析,结果表明:此次强降水是在西太平洋副热带高压控制下产生的,副高外围中低层西南暖湿气流带来了水汽和不稳定能量;卫星云图和雷达上表现为中β尺度对流雨团和多个γ尺度强对流雨团;0~6 km中等强度的垂直风切变,对流不稳定能量和中低层强辐合,为短时暴雨的产生提供有利的环境场;地面图上干线触发了暴雨的产生。中尺度辐合的维持,使得飑线附近不断触发新的对流雨团,tBB＜－60 ℃区域与短时暴雨落区有较好的对应关系。分级最优Z-I反演降水估测产品能更好地反映中尺度对流性降水的量级,对预报员判别短时强降水具有指示作用。     

“0713"山西短时强降水天气的潜势及触发条件分析

利用常规观测资料、NCEP 1°×1°再分析资料、FY-2G卫星逐时TBB资料、多普勒雷达及自动站资料,对2018年7月13日夜间出现在山西东南部的短时强降水天气进行了潜势及触发特征分析。结果表明:副高外围的强劲西南气流为本次短时强降水过程提供了充沛的水汽条件;"上干冷下暖湿"的层结结构与"高层冷平流、低层暖平流"的温度差动平流提供了强对流发生发展所需的能量条件;上升运动的形成和维持有利于不稳定能量的释放和增强。地面β中尺度辐合线发展为β中尺度涡旋,激发β中尺度对流云团的合并与加强;大于等于35 dBZ的β中尺度带状回波中镶嵌的γ中尺度对流单体,在500 hPa西南气流的引导下,形成高度组织化的多单体线状回波缓慢移动是形成局地短历时强降水的直接原因。     

一次阻塞形势下的内蒙古暴雨过程特征分析

利用常规气象观测资料、1°×1°NCEP再分析资料、FY-2E逐时云顶亮温(TBB)资料和1 h降水资料,对2012年7月24 31日内蒙古全区性暴雨过程进行了分析。结果表明:(1)此次暴雨天气过程发生在南亚高压东伸、贝加尔湖阻塞形势稳定和西太平洋副热带高压位置偏北的大尺度环流背景条件下。(2)地面辐合以及700 h Pa切变和涡旋是暴雨发生的影响系统,中尺度对流系统(MCS)是暴雨过程中短时强降水的直接制造者,中尺度雨团出现在MCS边缘TBB梯度最大处冷空气一侧。(3)暴雨发生时南海季风涌活跃,为暴雨的发生提供了充沛水汽条件,暴雨发生前对流层低层存在大量不稳定能量,高空急流入口区右侧与低空急流出口区左侧相叠置耦合,以及地形的强迫动力抬升机制,触发了暴雨天气。(4)内蒙古西部地区水汽输送条件较差是该地区较少发生暴雨的主要原因。     

延安盛夏一次局地暴雨中尺度特征分析

利用常规观测资料、NCEP1°×1°再分析资料、FY-2E卫星资料和延安多普勒天气雷达资料,对2013年7月25日发生在延安地区的局地暴雨天气过程进行了初步分析,结果表明:本次暴雨发生在典型的中高纬两槽一脊形势下,西太平洋副热带高压西侧的偏南风急流形成了向陕西输送水汽和能量的重要通道;副高边缘西南暖湿气流向北输送形成陕西高温高湿天气,为暴雨产生积累了不稳定能量。700hPa和850hPa切变线与地面辐合线的重叠非常有利于边界层湿暖空气辐合抬升,激发对流单体的发生和强烈发展。中α尺度对流云团自西向东发展加强,依次造成延安北部县区的短时强降水;黄陵短时大暴雨出现在中β尺度对流云团发展到强盛阶段,在雷达回波上表现为对流系统持续的"列车效应"。     

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.     

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.     

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.     

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.