2016年湖北梅汛期一次极端强降雨的气象因子异常特征分析

利用NCEP/NCAR再分析逐日资料和其他常规观测资料,对2016年湖北省梅雨期一次罕见极端强降水过程气象因子的异常特征进行分析。结果表明:异常的高低纬度环流形势配合,为此次极端降水过程的发生提供了有利的环流背景。500 hPa副热带高压较气候平均值显著偏强,有利于副热带高压西侧水汽输送加强,使得低层南风距平较气候平均值异常偏强;850 hPa低涡强烈发展配合200 hPa分流区的形成,导致垂直方向上动力抬升也表现出一定的异常性;此外对该过程中极端降水站点上空的气象因子分析发现,水汽因子(PW)、不稳定因子(K指数)和动力因子(850 hPa散度)绝对值均比气候平均值偏高了1.5个σ以上,并且超过历史相关统计值的上四分位值。最后给出了此次过极端强降水过程的天气概念模型及气象因子异常度的定量配置图。     

“21·7”河南极端强降水特征及环流异常性分析

基于国家自动站及区域自动站降水观测资料、欧洲中心大气再分析资料（ERA5）分析了河南“21·7”过程的降水特征及环流和物理量的异常性，并对比1981年以来郑州和鹤壁50 mm以上强降水过程的物理量特征。结果表明：1）“21·7”强降水过程在累计降水量、强降水覆盖范围、日雨量和小时雨强等方面均表现出显著极端性，过程累计降水量超过400 mm的站点集中分布在太行山东麓沿山地区和伏牛山东侧迎风坡一侧，与地形关系十分密切。2）南亚高压增强东伸，副热带高压异常偏强偏北，低纬度地区活跃的低值系统等大气环流异常，导致了水汽稳定持久向河南输送，太行山和伏牛山沿山一带水汽辐合偏离气候态最强超过-10σ，表现出显著极端性。3）“21·7”过程中，动力条件的异常特征十分显著，200 hPa的辐散中心分别位于伏牛山和太行山东麓沿山一带，相较历史气候态偏离度达到2σ～5σ；伏牛山沿山一带850 hPa涡度偏离气候态程度较太行山东麓一带更大，达6σ；而700 hPa上升运动则是太行山东麓一带极端性更强，标准差达-3σ～-5σ。4）与1981年以来同区域暴雨过程相比，“21·7”过程中，850 hPa涡度和700 hPa垂直速度的标准差为历次过程最大（最小）或次大（次小）者，对暴雨极端性有指示意义，地形附近历次暴雨过程物理量统计显示，伏牛山和太行山东麓的850 hPa辐合及700 hPa垂直速度平均偏离气候态超过3σ（-3σ），且偏离程度与日雨量呈正相关。     

江西春季降水异常的环流特征及其对ENSO事件的响应

利用江西省83个气象观测站1961—2018年春季(3—5月)逐日降水资料和NCEP/NCAR逐日再分析资料,对江西春季降水异常的大气环流特征及其对ENSO事件的响应进行了研究。结果表明:江西春季降水异常偏多年,中层500 hPa中高纬地区受欧亚型环流(EU型)影响,乌拉尔山附近阻塞高压系统活动频繁,贝加尔湖地区低槽偏强,西太平洋副热带高压(简称西太副高,下同)偏强,有利于北方冷空气南下并与偏南暖湿气流在江西上空交汇;低层850 hPa菲律宾以东西太平洋地区为异常反气旋环流控制,造成南海水汽向江西地区输送加强。而江西春季降水异常偏少年,其环流特征表现则与之相反。ENSO是影响江西春季降水的重要强迫信号,厄尔尼诺(拉尼娜)衰减年,春季东亚地区低层850 hPa西太副高偏强(弱),有(不)利南海上空水汽向江西地区输送,低层辐合(辐散)和高层200 hPa辐散(辐合)形成的动力抬升条件是造成江西地区降水偏多(少)的主要原因。     

2017年6月上旬江苏南部一次极端暴雨过程分析

从环流形势、弱冷空气影响、大气稳定度、水汽收支等方面分析了2017年6月上旬江苏南部的一次极端暴雨过程,并与该区域同期其他暴雨事件进行了对比.结果表明,暴雨区位于加强的200 hPa西风急流入口区的右侧,偏强的副热带高压西北侧的西南气流与东北冷涡西南侧的西北气流交汇及850 hPa异常的风场切变是造成本次强降水过程的重...     

“0711”山西晋城极端强降水过程的宏微观特征分析

利用ERA5逐小时0.25°×0.25°再分析资料、地面自动监测站以及FY-4A卫星、多普勒雷达、激光雨滴谱仪等精细化监测资料,对2021年7月11日山西晋城极端强降水过程的宏微观特征进行分析。结果表明：（1）此次极端强降水是继1961年以来晋城7月降水出现的第二高极端降水;高空急流入口区右侧强辐散、低空急流出口区风速辐合、低涡暖式切变线附近强辐合是极端强降水的宏观动力条件;低空急流将水汽源源不断向极端强降水区输送,整层大气可降水量高达65 mm以上是极端强降水发生的宏观水汽条件;500 hPa高度槽超前700 hPa和850 hPa冷式切变线是此次极端强降水发生的宏观动力不稳定条件。（2）极端强降水落区位于500 hPa高度槽、 850 hPa和700 hPa暖切变线、地面干线所围成的不规则四边形区域,且与500 hPa T-Td≤4℃、 700 hPa T-Td≤3℃、 850 hPa T-Td≤2℃、 Ki指数≥38℃、 Si指数≤-1℃所控制的区域相重叠,在对流云团西南侧亮温梯度的大值区和云团西南部的低亮温区,即在地面干线和地面中尺度切变线0～30 km范围内极端降水量最大。（...     

1991年5-7月江淮洪涝:水汽和冷空气的作用比较

对1991年5-7月江淮流域持续性暴雨的环流异常进行分析,比较造成此次洪涝的水汽输送和冷空气活动重要性。结果表明：（1）东亚大槽维持在中国东北上空发展明显,同时鄂霍次克海上空没有建立强大阻高,这种形势有利于冷空气持续向南侵袭,盛行经向环流。此外,低纬度地区,西太平洋副热带高压主体位置于常年同期相比,明显偏西、偏强,有利于暖湿气流沿副热带高压北上到达江淮流域,与北方冷空气辐合形成强降水。（2）通过定义I_T和I_q分别表征温度与水汽对降水的贡献,发现此次江淮流域地区强降水是由对流层低层水汽异常增多和气温异常偏低共同造成的,作用基本相当。     

两类El Ni?o事件对华南前汛期降水异常的影响

利用观测资料及模式结果探讨了EP/CP El Ni?o事件对华南前汛期（4—6月）降水异常的影响。结果发现,EP和CP型相关的华南前汛期降水异常分布之间存在明显月际差异,表现为4、5月EP（CP）型相关的降水异常以偏多（少）为主;6月则相反,EP（CP）型的降水呈负（正）异常分布。分析表明,EP型相关的4、5月偏强的副热带高压与850 hPa上西北太平洋反气旋异常相配合,有利于水汽从海洋向陆地输送,且两广地区水汽辐合,降水异常偏多;而6月相关的500 hPa异常场上对应偏强的东亚大槽,不利于水汽输送,且广东地区处于水汽辐散区,对应降水偏少。CP型相关的4、5月对应500 hPa上东亚大槽偏强,不利于水汽往陆地输送,且华南为水汽辐散,降水偏少;6月的500 hPa上呈现“+-+”的东亚-太平洋遥相关波列（EAP）型,华南地区为明显的水汽辐合,降水偏多。GFDL模式较好地再现了EP /CP型的4、5月降水异常分布及大气环流形势,但是对6月的模拟存在一定偏差。      

"06.7"郧西暴雨天气的成因分析

利用常规气象资料和卫星云图资料,采用天气学诊断方法,从大尺度环流背景、天气系统、物理量场、对流云团演变特征等方面,分析了2006年7月3～4日出现在湖北郧西的一次暴雨天气过程的成因。结果表明,此次暴雨是在副热带高压减弱东退形势下产生的;700 hPa和850 hPa的冷槽、切变线是此次强降水的主要影响系统,暴雨区位于700 hPa切变线右侧、850 hPa切变线附近;暴雨区上空存在明显正涡度柱,低层辐合与中高层辐散形成抽吸作用,为暴雨过程发生发展提供了动力条件;存在于孟加拉湾至我国西南地区的水汽通道为暴雨过程提供了必需的水汽;整个暴雨过程都伴随着中尺度对流云团的初生、发展、合并和减弱,降水主要由发展型对流云团造成。     

华北近60年夏季降水年际异常与大气动力、水汽条件关系的研究

本文基于华北夏季降水数据、NCEP/NCAR再分析环流数据,采用了相关、合成和环流异常回归重构等方法,分析了东亚副热带夏季风指数、华北大气动力上升指数与华北夏季降水的关系。主要结果如下：1）东亚副热带夏季风指数、华北大气动力上升指数与华北夏季降水有很好的对应关系。当两个指数偏强时,华北夏季降水会异常偏多;两个指数偏弱,华北夏季降水异常偏少;如果两个指数强弱不一致时,华北会出现区域性降水偏多情况,但全区整体降水量基本为正常值。2）华北夏季降水异常是东亚副热带夏季风和华北大气动力上升运动协同作用的结果。在东亚副热带夏季风指数、华北大气动力上升指数偏强年,夏季500hPa层贝加尔湖槽会加深、西北太平洋副热带高压会偏北,华北处于“东高西低”的环流型控制下,西部低槽东移受阻,在华北维持较长时间的大气上升运动;850hPa层印度夏季风、东亚副热带夏季风会偏强,这时热带印度洋西风水汽输送以及东亚副热带地区偏南风水汽输送或东南风水汽输送会加强,华北水汽来源充足。这种高、低空环流配置非常有利于造成华北夏季降水异常偏多。反之,华北夏季降水会异常偏少。3）前期4—5月,东亚副热带夏季风指数、华北大气动力上升...     

2018年广西一次极端低温雨雪冰冻灾害成因分析

利用NCEP和FNL再分析资料及地面气象观测站气温等观测资料,对2018年12月28日至31日广西发生的一次极端低温雨雪冰冻事件进行天气形势分析.结果 表明,乌拉尔山阻塞高压强而稳定,贝加尔湖附近500hPa气温有-52℃的冷中心,同时与横槽配合,是地面冷空气中心堆积加强的原因;副热带高压的异常偏强,造成广西南北温差较大;中纬度锋区强盛,850hPa南北温度梯度达22℃,提供了热力和动力条件;中低层锋区的结构造成了广西北部和中部、南部降水相态的明显区别;持续且深厚的水汽输送为这次低温雨雪冰冻过程提供有利的水汽条件.     

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.