西宁两次强降水的雷达VWP特征

分析了西宁2次不同性质强降水的雷达径向速度和风廓线产品(VWP)特征,结果表明:西宁强降水开始前低层西南(SW)风速增大,中层风场出现“ND”(静止风),高层偏东风明显。过程最大降水量出现在低层风向明显转变的时段内。混合性强降水在高层强气流向下传递至低层时强降水开始或增大,强降水偏向高空平均气流的右侧;对流性强降水主要是低层强气流向下传递,偏向高空平均气流右侧的幅度较小;中层ND楔形块是强降水开始的先兆。     

黔中地区一次暖区暴雨的中尺度特征分析

利用自动站加密观测资料、ERA5再分析资料、FY-2F云顶亮温资料和雷达产品资料等,对2019年5月24日夜间黔中地区暖区暴雨过程的中尺度对流系统特征及成因进行分析,结果表明：（1）此次暖区强降水过程具有持续时间长、小时雨强大、强降水范围广等特点;（2）高能高湿的环境及强的大气层结不稳定特征、深厚的暖云层以及较低的抬升凝结高度和自由对流高度,为高效率持续性降水的产生提供了有利条件;（3）本次暖区暴雨主要由2个对流发展旺盛且伸展高度较高的对流云团连续影响造成,其移动路径在黔中地区存在叠加效应;（4）暴雨由积云为主的积层混合降水回波长时间滞留造成,具有明显的“列车效应”,降水强回波质心低,具有热带降水型回波的特征;（5）地面辐合线为对流系统的发生发展提供了较好的动力条件。强降水落区的位置随着地面辐合线的移动而移动,同时强降水落区主要位于地面辐合线左侧的偏北气流内。     

黑龙江省一次伴有龙卷的暖区暴雨成因分析

2014年7月19日夜间黑龙江克山出现雨强超过90 mm的短时强降水,利用常规观测资料、区域站资料、NCEP/NCAR再分析资料等对此次冷锋前部的暖区强降水成因进行分析。结果表明:(1)此次强降水出现在580 dagpm线附近,副高诱发的超低空急流为强降水提供了充沛的水汽和不稳定能量。(2)地面辐合线和地形抬升触发对流。高空急流东移,高空急流出口区左侧和辐散区与低层辐合相耦合促使对流快速发展增强。耦合消失,强降水则快速减弱。(3)低层暖平流明显,尤其地面具有暖锋锋生特征。强降水出现在不稳定层结和上升运动快速增强的阶段。(4)地面～200 hPa辐合层形成深厚的上升运动区,促使对流快速发展。(5)中尺度对流雨带沿地面辐合线生消。降水先出现在暖湿舌前部。随后,强降水产生的冷空气抬升暖湿空气形成冷锋特征的降水,由于强降水和冷空气的正反馈作用,降水持续时间长。冷空气势力最强时,伴随中尺度气旋性环流及0～1 km强垂直风切变有利于龙卷产生。(6)开口状地形的辐合作用、抬升及局地地形导致的中尺度环流风场对暖区降水的形成和维持作用显著。     

海南岛"0810"特大暴雨物理量诊断及多普勒特征分析

应用常规观测、海口多普勒回波及NCEP1×1°再分析等资料,对2008年10月12～15日海南特大暴雨成因进行诊断分析,并揭示了暴雨过程中的多普勒回波特征.结果表明:导致海南岛产生强降水的主要原因是热带低压移动缓慢和弱冷空气的低层入侵;当冷暖空气交绥,大气温湿结构发生突变,θse面陡立造成对流系统斜压发展,激发位势不稳定能量释放.正差动假相当位温平流意味着低层暖湿空气的平流大于高层,加强了层结对流不稳定发展;在斜压扰动作用下,对流层中层正差动涡度平流和低压东侧的暖平流破坏了海南岛的准地转平衡,动力强迫和热力强迫共同作用激发了次级环流,导致暴雨区上空的垂直运动的发展,促使暴雨增强.充沛的水汽输送及水汽的强烈辐合,为暴雨发生的有利水汽条件.多普勒径向速度揭示了暴雨区低层冷平流高层暖平流、风向风速的垂直切变大的垂直结构以及持续性的强烈辐合等等特征,回波停滞和"列车效应"使降水增幅,降水回波的性质差异,可造成强降水区域分布的不同.     

海南岛“0810”特大暴雨物理量诊断及多普勒特征分析

应用常规观测、海口多普勒回波及NCEP1×1°再分析等资料,对2008年10月12～15日海南特大暴雨成因进行诊断分析,并揭示了暴雨过程中的多普勒回波特征。结果表明：导致海南岛产生强降水的主要原因是热带低压移动缓慢和弱冷空气的低层入侵;当冷暖空气交绥,大气温湿结构发生突变,θse面陡立造成对流系统斜压发展,激发位势不稳定能量释放。正差动假相当位温平流意味着低层暖湿空气的平流大于高层,加强了层结对流不稳定发展;在斜压扰动作用下,对流层中层正差动涡度平流和低压东侧的暖平流破坏了海南岛的准地转平衡,动力强迫和热力强迫共同作用激发了次级环流,导致暴雨区上空的垂直运动的发展,促使暴雨增强。充沛的水汽输送及水汽的强烈辐合,为暴雨发生的有利水汽条件。多普勒径向速度揭示了暴雨区低层冷平流高层暖平流、风向风速的垂直切变大的垂直结构以及持续性的强烈辐合等等特征,回波停滞和＂列车效应＂使降水增幅,降水回波的性质差异,可造成强降水区域分布的不同。     

2012年盛夏山东西部一次短时强降水天气的形成机制

利用常规观测资料、自动站加密观测资料、卫星云图和雷达资料,对2012年7月4日山东省西部一次短时强降水的天气形势、物理量条件、云图和雷达回波特征进行分析。结果表明：在有利降水的大尺度天气系统背景下,低层冷空气和中尺度天气系统造成了本次短时强降水天气;低层925hPa和1 000 hPa的充沛水汽和辐合上升运动有利于强降水天气的发生,正涡度中心对应强降水中心;地面辐合线和低压环流造成本次短时强降水天气;中尺度对流云团和地面中尺度系统相对应,其位置和维持时间与强降水的落区和时间基本一致。雷达组合反射率因子〉45 dBZ的强回波区与强降水落区基本吻合;雷达平均径向速度产品逆风区中辐合流场的出现和维持及回波顶高的上升对应地面中尺度气旋式环流的形成和维持;逆风区中辐散流场的出现和维持及回波顶高的下降,对应地面中尺度气旋式环流的减弱;短时强降水出现的初期,垂直累积液态水含量出现了一个峰值,峰值出现时间提前于较强降水时段。     

湘中一次低涡切变暴雨过程诊断分析

利用常规观测资料、NCEP 1°×1°逐6 h 再分析资料、FY-2E 静止卫星红外云图反演的逐时TBB 资料及长沙多普勒天气雷达产品,对2011 年6 月10 日由低涡切变系统引发的湘中区域暴雨进行诊断分析。结果表明: 湘中暴雨发生在高空低槽与中低层低涡相配合的环流背景下,暴雨中心具有低层正涡度(辐合)、高层负涡度(辐散)的垂直结构;此次湘中暴雨过程强降水的出现与TBB 最低值并不同步,而是落后于TBB 最低值1～3 h,强降水区主要出现在云团后侧TBB 梯度较大区域内;该暴雨回波为典型的混合性降水回波,逆风区移过的地区对应强降水区,逆风区出现后的半个小时内为强降水时段,逆风区消失后降水明显减弱,中层弱冷空气增加了暴雨区对流性不稳定。     

闽北一次初春强降水的成因分析

利用常规观测资料、NCEP 1°×1°再分析资料、新一代天气雷达资料,对2012年3月6日-7日福建省北部地区暴雨成因进行诊断分析。结果表明:此次降水过程在高空西风槽南下带来的冷空气与西南暖湿气流交汇的背景下产生,暴雨区位于低空西南急流北侧、低层切变南侧、地面冷锋附近;强降水落区位于层结不稳定的湿区中,低层辐合、高层辐散有利于对流发展;干冷空气的侵入时高层高值位涡库向北向下伸展,促使中低层气旋涡度发展,从而导致强降水的发生;雷达回波分析表明,低层暖平流、高层冷平流、区域上空辐合形势都有利于对流性降水的产生。     

迎风坡暴雨预报中多普勒天气雷达资料两种散度反演方法的应用

简单介绍了由多普勒天气雷达径向风资料反演平均散度和径向散度的计算方法,以2004年7月11—12日暴雨过程为例说明两种散度在迎风坡暴雨跟踪、预报中的综合应用。分析结果表明：①平均散度可以作为降水跟踪、预测的背景场。降水出现之前,低层平均散度存在辐合;低层辐合加强或维持,整个区域降水将加强;辐合高度抬升到中层并维持,降水达到最强;辐合减弱并开始出现辐散,区域降水将逐渐结束。②根据径向散度的分布情况,可以提前2 h以上预报强降水的落区。强降水落在径向辐合大值区后部的较弱辐合区内,且弱辐合区强度越强,未来降水强度越大。因此,综合分析平均散度和径向散度随时间的变化,可以跟踪、预测降水的发展演变,特别是可以给出暴雨的大致落区。     

2009年“8·17”鲁南低涡暖式切变线极强降水分析

利用各种观测资料及NCEP/NCAR 1°×1°再分析资料,对2009 年8 月17—18 日鲁南极强降水进行多尺度分析。结果表明: 强降水由500 hPa 西风槽、850 hPa 暖式切变线和地面倒槽共同影响产生。强降水发生前,中低层湿层深厚且有弱的水汽辐合,大气对流不稳定,并有较高对流不稳定能量。低层暖式切变线辐合、暖平流以及中高层正涡度平流、侧向辐合和倾斜涡度发展,使垂直涡度增大、上升运动发展;低层东南气流与高空槽配合产生次级环流,其上升支使上升运动增强,触发对流不稳定能量释放并产生强对流,造成强降水。强降水期间,中高层弱冷空气侵入使对流加强和降水强度加大。中尺度对流云团产生在地面低压倒槽东部和中尺度辐合线附近,地面加热和冷却不均匀导致低压倒槽中小尺度温度梯度加大,极端强降水中心出现在小尺度温度梯度区。强降水由长条形中尺度对流系统及其北端发展的圆形中尺度对流云团产生;中尺度对流系统(云团)自西向东缓慢移动,在回波强度图上表现为气旋性向北汇合的带状强回波。     

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。     

CHARACTERISTICS AND TRENDS OF CLIMATIC EXTREMES IN CHINA DURING 1959–2014

The spatial and temporal variations of daily maximum temperature(Tmax), daily minimum temperature(Tmin), daily maximum precipitation(Pmax) and daily maximum wind speed(WSmax) were examined in China using Mann-Kendall test and linear regression method. The results indicated that for China as a whole, Tmax, Tmin and Pmax had significant increasing trends at rates of 0.15℃ per decade, 0.45℃ per decade and 0.58 mm per decade,respectively, while WSmax had decreased significantly at 1.18 m·s~(-1) per decade during 1959—2014. In all regions of China, Tmin increased and WSmax decreased significantly. Spatially, Tmax increased significantly at most of the stations in South China(SC), northwestern North China(NC), northeastern Northeast China(NEC), eastern Northwest China(NWC) and eastern Southwest China(SWC), and the increasing trends were significant in NC, SC, NWC and SWC on the regional average. Tmin increased significantly at most of the stations in China, with notable increase in NEC, northern and southeastern NC and northwestern and eastern NWC. Pmax showed no significant trend at most of the stations in China, and on the regional average it decreased significantly in NC but increased in SC, NWC and the mid-lower Yangtze River valley(YR). WSmax decreased significantly at the vast majority of stations in China, with remarkable decrease in northern NC, northern and central YR, central and southern SC and in parts of central NEC and western NWC. With global climate change and rapidly economic development, China has become more vulnerable to climatic extremes and meteorological disasters, so more strategies of mitigation and/or adaptation of climatic extremes,such as environmentally-friendly and low-cost energy production systems and the enhancement of engineering defense measures are necessary for government and social publics.     

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;