贵州西部一次秋季暴雨预报偏差分析

2021年9月16日预报夜间贵州西部将出现暴雨-大暴雨天气,实况以小到中雨、分散暴雨为主,本文利用常规及加密观测资料、NCEP/NCAR再分析资料、ECMWF、CMA-GD、CMA-SH9等模式预报产品,对这次暴雨空报的原因进行探讨,结果如下：(1)本次暴雨-大暴雨空报的主要原因：副高夜间略北推增强,有利下沉气流增强,阻止切变线南下且消弱低层切变的强度;整体动力条件较差,低层辐合厚度、强度不够,且迅速转为辐散,涡度平流由正转负、上升运动较弱。(2)模式出现较明显误差：ECMWF错误预报副高夜间位置,切变线位置预报也有偏差,CMA-GD模式错误预报切变线位置;5家数值模式预报量级均偏大,其中CMA-GD、CMA-SH9及贵州WRF偏大明显,ECMWF的量级及落区预报和实况更为接近。(3)预报员过度相信ECMWF对切变线的位置预报、过度相信CMA-GD对极端降水的把握,忽视副高略北推增强、动力条件差导致的触发难度迅速加大,主观预报的优势没有发挥出来。     

北疆北部2次区域性暴雨的中尺度环境场分析

对12h24mm以上强降水带的预报,模式输出的降水资料是预报的重要依据,但有时偏差较大。依据中尺度分析技术,利用常规资料、EC细网格和T639模式12h预报场对2013年夏季发生在北疆北部的2次区域强降水过程中12h最强降水时段的环境场进行中尺度分析。结果表明,中亚低槽北上强降水落区位于500和700hPa中尺度气旋的第一、四象限及对流层低层冷槽的右侧,850hPa切变线附近,地面中尺度高压前部、边界线和切变线附近及干线西侧的重合区域。西西伯利亚低涡型暴雨位于中尺度短波槽前、高空西南急流出口区左侧辐散区,700和850hPa切变线西侧及干线西南部,850hPa偏西、偏东及东南3股气流汇合区,地面干线的西部、辐合线东部及切变线附近的重叠区域。中亚低槽北上暴雨天气为非典型暴雨易漏报。用模式12h预报场制作高空综合图,可提高预报时效,EC细网格优于T639模式。     

金华市一次暴雨过程成因及EC预报误差分析

利用常规气象观测资料、区域自动站加密资料、欧洲数值模式(ECMWF,简称"EC")资料对2018年5月7日08时至8日08时出现在金华市的一次暴雨过程进行成因分析,并将EC预报的环流形势、物理量场与实况进行对比分析,找出预报误差产生原因,提出春夏交替季节暴雨落区预报的订正着眼点。分析结果表明,此次暴雨落区沿850 hPa切变线呈带状分布,高低空系统呈后倾槽结构,强降水主要位于850 hPa切变线附近,地面倒槽顶后部;降水前期低空急流的建立为暴雨区输送了充分的水汽,与高空急流的耦合作用加强了上升运动;低层冷空气入侵为斜升不稳定提供了动力条件,江南倒槽及地面中尺度辐合中心的抬升触发作用加强了此次降水。而EC的暴雨落区预报偏东偏南,金华市暴雨漏报,浙南和东南沿海的暴雨空报,其主要原因:一是形势场和物理量场预报与实况有偏差;二是没有考虑到高低空系统呈后倾槽配置,暴雨倾向于出现在倒槽后部。低层弱冷空气迫使暖湿气流爬坡斜升,使暴雨落区偏北;三是没有结合中尺度模式来调整中尺度辐合中心的位置;四是没有根据特殊地形的抬升作用来调整暴雨落区。以上4点也是对此次数值预报暴雨落区进行订正的着眼点。     

基于多模式2015年江西省汛期区域性暴雨的检验

利用24 h降水实况资料和高空实况形势场资料、ECMWF模式形势场预报资料及ECMWF、JMA、T639模式降水预报资料,对2015年江西省汛期(4月上旬至7月上旬)区域性暴雨的时空分布特征进行分析,并对2015年江西省汛期区域性暴雨的影响系统和降水预报结果进行了短期主观检验,对比分析了ECMWF、JMA和T639等3种数值模式对江西省区域性暴雨系统预报的效果。结果表明:ECMWF模式对江西省汛期暴雨天气系统的调整和演变具有一定的预报能力,如对副热带高压和西南急流的预报;但随着预报时效增加,预报误差增大。ECMWF模式预报的48 h和72 h副热带高压强度较实况明显偏弱,预报的副热带高压西脊点位置偏东,随着季节转变预报的副热带高压强度明显偏弱,其中24 h预报的准确率较高。ECMWF模式对高空槽的预报基本准确;ECMWF模式对切变线移动的总体预报效果较好,72 h预报的切变线移动偏慢;ECMWF模式对700 hPa西南急流强度的预报易偏弱,对850 hPa和925 hPa西南急流的预报易偏强;ECMWF模式预报的急流轴位置多数偏北;ECMWF模式对低层比湿的预报较实况偏强。随着预报时效临近,ECMWF、JMA和T639等3种数值模式对江西省汛期区域性暴雨的预报具有较强的调整能力;JMA模式预报的暴雨与实况最接近,表现出对雨带分布具有较强的预报性能,但对降水量级预报偏弱;ECMWF模式对降水强度的预报性能较好,预报的降水分布总体偏北;T639模式预报的主雨带范围较实况偏大,3个模式均存在对暴雨以上量级降水漏报的问题。     

基于多模式2015年江西省汛期区域性暴雨的检验

利用24 h降水实况资料和高空实况形势场资料、ECMWF模式形势场预报资料及ECMWF、JMA、T639模式降水预报资料,对2015年江西省汛期(4月上旬至7月上旬)区域性暴雨的时空分布特征进行分析,并对2015年江西省汛期区域性暴雨的影响系统和降水预报结果进行了短期主观检验,对比分析了ECMWF、JMA和T639等3种数值模式对江西省区域性暴雨系统预报的效果。结果表明:ECMWF模式对江西省汛期暴雨天气系统的调整和演变具有一定的预报能力,如对副热带高压和西南急流的预报;但随着预报时效增加,预报误差增大。ECMWF模式预报的48 h和72 h副热带高压强度较实况明显偏弱,预报的副热带高压西脊点位置偏东,随着季节转变预报的副热带高压强度明显偏弱,其中24 h预报的准确率较高。ECMWF模式对高空槽的预报基本准确;ECMWF模式对切变线移动的总体预报效果较好,72 h预报的切变线移动偏慢;ECMWF模式对700 hPa西南急流强度的预报易偏弱,对850 hPa和925 hPa西南急流的预报易偏强;ECMWF模式预报的急流轴位置多数偏北;ECMWF模式对低层比湿的预报较实况偏强。随着预报时效临近,ECMWF、JMA和T639等3种数值模式对江西省汛期区域性暴雨的预报具有较强的调整能力;JMA模式预报的暴雨与实况最接近,表现出对雨带分布具有较强的预报性能,但对降水量级预报偏弱;ECMWF模式对降水强度的预报性能较好,预报的降水分布总体偏北;T639模式预报的主雨带范围较实况偏大,3个模式均存在对暴雨以上量级降水漏报的问题。     

基于ECMWF模式的江西及周边地区锋面暴雨预报检验和订正

利用全国降水资料（包括江西加密降水资料）、探空资料、ECMWF模式72—24 h降水和形势预报资料,采用天气学检验、SAL定量降水预报检验等方法,对2017—2019年江西及附近地区锋面暴雨的实况和模式产品进行检验分析,检验主要影响天气系统预报效果,得出ECMWF模式降水预报误差分布特征及原因,并对模式的暴雨预报进行订正。结果表明：ECMWF模式对2017—2019年锋面暴雨过程预报较实况大多偏北,落区预报误差主要源于大尺度降水。从锋面暴雨三种SAL分析误差可见,落区预报较实况大多偏北,暴雨过程强度多数较实况偏弱,结构较实况偏小。对误差较大个例的分析得出两点订正思路：1） 锋区南侧有较明显动力热力对流发展的弱锋区暴雨,暴雨落区可订正至925 hPa锋区南侧高温高湿区。2） 较强锋面暴雨,当中低层切变辐合抬升区重叠时,暴雨落区可向925 hPa锋区位置调整,暴雨通常不易出现在锋区北侧冷区。     

四川两次副高边缘型暴雨的预报偏差分析及模式检验对比

该文利用常规观测资料(实况探空资料、自动站雨量数据)以及ECMWF、SWC-WARMS(西南区域模式)、GRAPES-MESO、GRAPES-GFS对比分析了2019年在副高边缘环流形势下的2次四川盆地区域性暴雨天气过程。结果表明：(1)初始场相似的2次过程,导致强降水落区不同的主要原因在于副高的动态变化不同,其次西风带槽脊的细微差异以及低层水汽条件的差异也与降水落区息息相关。(2)ECMWF在这2次过程中对副高位置动态变化的预报,西进较东退更为准确,且数值模式对此类大范围强降水的预报,ECMWF较其它模式更具有优势,但局限性在于范围偏小、量级偏弱,可结合SWC-WARMS进行订正,而GRAPES-GFS、GRAPES-MESO在模式稳定性和预报准确率方面都不及上述两者。     

山东省极端强降水天气概念模型研究

利用山东省1971—1999年逐日降水资料,采用百分位法确定各站极端强降水阈值。据此阈值,在2000—2009年中挑选了39个极端强降水天气过程并进行天气分型,得到高空槽类、副高外围类、切变线类、气旋类、热带气旋类5类极端强降水概念模型。研究表明:切变线类、气旋类和热带气旋类暴雨区范围较大,而高空槽类和副高外围类暴雨区范围较零散;5类极端强降水均伴有低空急流,暴雨区一般位于700 hPa与850 hPa切变线(或槽线)之间、低空急流左侧风向风速辐合处;高空槽类、副高外围类、切变线类一型和气旋类均有冷空气影响,暴雨区位于850 hPa冷温度槽前部;5类极端强降水的产生机制不同,落区与θse的配置也不尽相同。     

2014年河南汛期久旱转雨过程分析及模式预报检验

利用常规气象观测资料、土壤相对湿度监测资料以及数值模式预报产品对2014年汛期的久旱转雨过程进行了分析和检验。结果表明:环流调整是久旱转雨过程的必要条件;500h Pa高空槽东移配合中低层切变线和低空急流东伸加强及地面倒槽发展形成了此次天气过程;低空急流发展为此次暴雨提供充沛的水汽,暴雨落区与水汽通量和水汽通量散度以及垂直速度大值区位置相吻合,另外850~700h Pa大于64℃是此次暴雨预报的指标之一。对T639和ECMWF模式产品检验分析表明,两个模式都对稳定性降水预报有优势,ECMWF-THIN模式对降水预报有48小时提前量。     

2022年6月12—13日江西中南部暴雨成因与预报误差分析

利用常规探空和地面观测站资料、ERA5 0.25°×0.25°再分析资料和ECMWF预报资料,对2022年6月12—13日江西中南部的暴雨过程进行分析。结果表明：1） 此次暴雨过程是在副热带高压和南亚高压稳定少动、西风槽携带冷空气南下的环流背景下,500 hPa高空槽、低层切变线、低空西南急流和地面静止锋共同作用造成的。2） 低层辐合、高层辐散产生深厚的垂直上升运动,为强降水的持续提供动力条件,低空暖湿西南急流输送的充足水汽,有利于江西中南部不稳定能量的积累。3） EC暴雨落区预报偏北的主要原因是天气系统位置较实况偏北,700 hPa垂直速度大值区偏北、对流性降水预报偏弱和地形影响也是暴雨漏报的重要因素。4） 584 dagpm特征线的位置变化对此次暴雨落区向南订正有较好的指示意义。在暴雨预报中,不仅要考虑锋面大尺度降水,还要考虑暖区对流性降水,关注低层强动力辐合区域,结合中尺度数值模式产品,可以有效对主雨带位置和强度进行订正。     

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.