Analysis of the Rainstorm Falling Zone in Guangxi during Influence Period of the 0906 Typhoon "Molave"

[ Objective] The research aimed to analyze rainstorm falling zone in Guangxi during influence period of the 0906 typhoon ＂ Molave＂. [ Method] For the heavy precipitation falling zone in southern and central parts of Guangxi after 0906 typhoon ＂ Molave＂ landed, 500 hPa circula- tion, physical quantity field, satellite cloud chart and terrain effect were analyzed. [ Result] 500 hPa subtropical high caused asymmetry of the ＂Me- lave＂ circulation, playing a key role for the strong precipitation falling zone in Guangxi. Physical quantity field analysis pointed out that after ＂ Me- lave＂ landed, water vapor convergence center was in southeast Guangxi, providing adequate moisture condition for the heavy precipitation in south- ern and central parts of Guangxi. The maximum positive vorticity center appeared at the middle and low layers in southern and central parts of Guangxi for a long time. At 200 hPa, there was a maximum divergence center. At 700 hPa, there was a maximum convergence center. High-level divergence and low-level convergence created conditions for heavy precipitation in the region. From satellite cloud chart, the heavy precipitation fall- ing zone related to asymmetric structure of the ~ Molave＂. In addition, uplifting effect of the terrain was conducive to occurrence of the large precipi- tation. [ Conclusion] The research provided reference for reduction and prevention of this kind of heavy precipitation.

Analysis of Special Strong Wind and Severe Rainstorm Caused by Typhoon Rammasun in Guangxi, China

Based on conventional meteorological observation data, NCEP 1° × 1° reanalysis data, reanalysis data with resolution 0.75° × 0.75° from ECMWF and Doppler weather radar, we analyzed the weather conditions and physical characteristics of Super Typhoon Rammasun (1409), which caused special strong wind and severe rainstorm in Guangxi. The results show that: 1) Typhoon Rammasun offshore sudden strengthening in one of the main reasons was that loop pressure ridge superimposed into the westward extension of subtropical high, to making enable rapid strengthening of the subtropical high, so the subtropical high advanced faster than the Rammasun move, Rammasun center of the subtropical high distance reduced and the gradient increased;2) Rammasun northward to south china coast with plenty of vapor following ITCZ, before landing, southwest monsoon and cross-equatorial flow were involved, Rammasun got latent heat of monsoon jet, enabling it to strengthen in offshore;3) Rammasun from the Qiongzhou Strait into the northern Gulf, therefore the Strait of short passages and both sides belong to the low zone, friction consumption smaller, that was the main reason what was able to maintain the strength of the super typhoon, when Rammasun into the Beibu Gulf;4) Diagnostic analysis shows that Rammasun before entering the northern Gulf and into the Beibu Gulf later, vorticity weakened, divergence and vapor flux divergence changed were smaller, meanwhile, vertical ascent speed and latent heat transport both increased, which was important reason of severe rainstorm caused by Rammasun.

Analysis of a Rainstorm Process Far from the Typhoon "Haitang"

Based on multiple kinds of observation data and NCEP/NCAR reanalysis data,the circulation background,cloud clusters and radar characteristics of a rainstorm far from the typhoon " Haitang" in Lianyungang,Jiangsu on the morning of July 31,2017 were analyzed,and causes of convection were discussed from the aspects of dynamic,thermal and water vapor conditions. The results showed that the rainstorm process was caused by convection cells with low center of mass,and strong convection mainly occurred in a position where temperature gradient at cloud top was the largest. In North China at 850 hP a,eastern cold air on the south side of anticyclonic circulation moved southwards and joined southeast air flow on the periphery of typhoon,which was the main reason for the occurrence of convection. The circulation of upper-level divergence and lowerlevel convergence was beneficial to the maintaining of convection. The convergence of southeast wind speed on the periphery of typhoon made water vapor accumulate,thereby providing enough water vapor for the appearance of heavy rainfall. K index had good denotative meaning to convection activity,and the process of convection with weak Cape value needs to be paid special attention to in business. The prediction effect of rainfall distribution and areas by the models EC and ECRC was superior to other models.

ON RELATION OF MESO-α INERTIA WAVE DEVELOPMENT TORAINSTORM ENHANCEMENT IN TYPHOON POLLY

Numerical simulation and diagnosis show that the amplified rainstorm from Typhoon Poily is related to the development/migration of meso-α gravity waves, inhomoseneous stratification distribution andcumulus convection latent heating feedback in the storm; such waves at a large scale are excited bylarge-scale nonlinear advection; substantially amplified ageostrophic wind perturbation resulting fromthe latent heating gives rise to intensified wave amplitude, leading to enhanced rising and thus torrentialrainfall; as the waves migrate towards reduced stability, wave energy is most likely to increase.

1632年华北地区暴雨洪涝事件研究

以历史文献为主要代用资料,重建了1632年华北地区暴雨洪涝事件的雨情、水情、灾情等,从而识别出1632年8月河南地区暴雨事件的时空范围,并与有器测记录的2021年河南极端降水事件进行对比。1632年华北地区大规模降水始于7月17日,从6月18日—11月11日,整个华北不同区域皆存有长时间降雨记录,且有多次强降水记录,造成黄淮地区雨涝,并使得黄淮交溃,对社会经济造成较大影响。梳理降水和洪涝的过程,区分了本地降水与客水的分布。将1632年8月河南暴雨洪涝与2021年7月河南极端降水事件对比发现,强降水位置相似,降水前后都有两个台风输送水汽,且1632和2021年华北地区夏季降水皆受到拉尼娜的影响,整体偏涝。

两次北上台风引发冀北极端降水的对比分析

利用NCEP/NCAR再分析资料、自动气象观测站数据,分析发生在河北省承德市的“安比”(1810)台风暴雨和“海棠”(1710)台风暴雨过程,比对冷空气活动、作用形式及其对降水的影响。结果表明:(1)两次过程在中纬度西风槽冷空气影响下的降水差异明显,“海棠”暴雨雨强明显强于台风“安比”,但后者降水生命史更长;(2)“海棠”残余环流北上影响承德市时,西风槽冷空气主体沿西北气流入侵环流,而台风“安比”暴雨过程仅受西风槽分裂出的弱冷空气影响。由于冷空气影响形式不同,前者的正涡度带沿切变区分布,大值区位于残余环流东侧,而后者的正涡度沿西风槽和台风环流分布,大值区位于环流西北侧。两次过程低层冷空气入侵均先于高层,较强冷空气影响台风环流时,有利于降水强度增强;弱冷空气影响环流时,则有利于降水强度维持。

台风“美莎克”对黑龙江的影响及其非对称结构特征

使用常规观测资料及ERA5(0.25°×0.25°)再分析资料,对2009号台风“美莎克”进行分析。结果表明:此次过程,副热带高压异常强大,位置偏北,并与北侧阻高合并形成高压坝阻挡;“美莎克”沿副高外围北上与中纬度低涡及冷空气相互作用,变性后斜压性明显加大,低涡增强;“美莎克”携带大量水汽,同时中低空急流将海上水汽持续向黑龙江输送,并在黑龙江强烈辐合,形成强的水汽辐合区和水汽辐合带;高低空急流耦合构成强的垂直环流,对应非常强的垂直上升速度;副热带高压向西北伸展,高空引导气流和热成风方向转为西北-东南向,促使“美莎克”登陆后向西北移动,穿过黑龙江,是黑龙江出现大暴雨的主要原因。分析台风中心涡度、散度、垂直速度、位温、湿位涡等物理量的三维结构变化,认识台风在北上登陆中的变性过程以及降水出现非对称结构的原因。

Numerical Study of the Mesoscale Systems in the Spiral Rainband of 0509 Typhoon Matsa

The Advanced Weather Research and Forecasting Model （ARW） is used to simulate the local heavy rainstorm process caused by Typhoon Matsa over the northeastern coast of Zhejiang Province in 2005. The results show that the rainstorm was caused mainly by the secondary spiral rainband of the Stationary Band Complex （SBC） structure. Within the secondary spiral rainband there was a strong meso-β-scale convergence line generated in the boundary layer, corresponding very well to the Doppler radar echo band. The convergence line comprised several smaller convergence centers, and all of these convergence columns inclined outward. Along the convergence line there was precipitation greater than 20 mm occurring during the following one hour. During the heavy rainstorm process, the Doppler radar echo band, convergence line, and the precipitation amount during the following one hour, moved and evolved synchronously. Further study reveals that the vertical shear of radial wind and the low-level jet of tangential wind contributed to the genesis and development of the convergence columns. The combined effect of the ascending leg of the clockwise secondary circulation of radial wind and the favorable environment of the entrance region of the low-level jet of tangential wind further strengthened the convergence. The warm, moist inflow in the lower levels was brought in by the inflows of the clockwise secondary circulation and uplifted intensely at the effect of convergence. In the convectively instable environment, strong convection was triggered to produce the heavy rainstorm.

家禽养殖场预防台风暴雨及抗灾自救策略

台风、暴雨等极端天气会对家禽业造成严重危害,出现养殖环境污染、疫病高发、防疫工作严峻等问题,必须给予高度重视,采取行之有效的措施,加强科学指导与饲养管理,从消灭病原体、杜绝传播途径、消除致病因素三方面入手,建立家禽疫情防御体系。为此,针对近些年台风对我国家禽产业造成的严重影响,通过查阅文献材料、结合现场工作实践,综述台风灾害对家禽生产的危害,提出一套预防台风暴雨及抗灾自救措施,希望能对家禽养殖从业者开展台风暴雨预防及抗灾自救工作提供技术支持。

台风暴雨下某建筑边坡稳定性分析研究

福建省由于独特的地理和气候条件,经常遭遇台风暴雨,导致滑坡灾害频发。基于强度折减理论,采用FLAC^(3D)软件,对福建龙岩市受2023年9月台风“海葵”中影响的某建筑边坡进行稳定性分析。考虑自重和台风暴雨2种工况,分析边坡的变形破坏机理。结果表明,在自重条件下边坡安全系数为1.676,处于稳定状态;台风暴雨后,安全系数下降至1.230,低于规范值,显示出失稳破坏的风险。台风季节的滑坡风险显著增加,边坡截面中塑性贯通破坏区域约5.0 m^(2),与实际滑坡面积相比误差为11.1%,为极端天气条件下的边坡稳定性评估提供了重要参考。

基于台风暴雨天气的水库洪水预报调度工作建议

近年来,我国极端暴雨天气事件增多,造成了严重灾害或重大影响。根据台风暴雨预报部署水库洪水调度工作,确保防洪安全,减轻灾害损失,有效拦蓄洪水资源,应当充分考虑到预报大暴雨、特大暴雨的不确定性,高度重视雨前准备、雨中实施洪水预报调度及雨后经验教训总结。文章针对近年来山东省水库洪水调度形势,以及目前存在的几个误区和暴露的短板问题,提出了基于台风暴雨预报的水库洪水预报调度工作建议,为防洪指挥决策提供参考。

浙江沿海两个台风暴雨环流过程的对比分析

“烟花”和“梅花”是两个均在浙江舟山登陆,并在浙江沿海产生强降水的热带气旋。本文利用常规气象站观测资料和ERA5再分析资料,对两个台风影响浙江沿海并造成台风暴雨的成因进行对比分析。结果表明:①“烟花”受多系统、缺少明确引导气流环境的影响,移动缓慢,降水时间长;“梅花”受冷空气南下渗透影响,台风变性,多集中性暴雨发生。②“烟花”有两条水汽输送带和两个明显的水汽辐合区,为长时间暴雨提供充足水汽;“梅花”只有一条水汽输送通道,但有一个相较“烟花”更加强烈的水汽辐合区,使暴雨落区更加集中,雨强更大。③“烟花”受长时间低层暖湿气流和垂直风切变维持的影响,降水时间长,但强度较弱;“梅花”影响期间,上升运动强烈,降水效率高,降水多由短时暴雨形成。

“21·7”河南特大暴雨成因分析及三维概念模型的构建

通过对“21·7”河南特大暴雨在地形效应、不同高度的大气环流和水汽输送通道的分析,结论如下:(1)台风“烟花”与副高形成的东南气流在底层灌入河南喇叭口地形,在地形热力抬升和动力阻挡抬升的共同作用下,有利于山前降水的形成。(2)在500 hPa中层,郑州涡旋处于两个高压的“鞍型场”内,该环流配置导致台风“烟花”、“查帕卡”和热带低压相互作用形成三股气流直达河南;在200 hPa高层,河南暴雨区辐散气流向东下沉到同一纬度的东海高层冷涡内,其次级环流进一步加强了河南云团的强度。(3)台风“烟花”和“查帕卡”输送丰沛水汽至河南中西部,受太行山和伏牛山地形阻挡,在山前形成强烈水汽辐合。(4)构建的河南极端暴雨概念模型通过水汽输送通道和次级环流,将环流、台风、低压系统和喇叭口地形等降水成因有机联系,并放入同一个构架之中,从宏观上了解这些成因的运行机理及其相互作用,可加深对该特大暴雨成因的理解。

陕北黄土高原一次区域性暴雨诊断分析

利用NCEP 1°×1°再分析资料和黄土高原东部288个自动站资料,分析了2018年7月10日区域性大暴雨过程。结果表明:冷涡底部下滑槽与副高外围暖湿气流的相互作用是形成这次暴雨的主要成因。远距离台风使低空急流加强,高低空急流耦合为暴雨的发生提供了强烈的动力条件。θ_(se)能量舌向河套地区的伸展与午后增温加剧了能量的增长,二者共同为暴雨区提供了热力条件。台风西进,副高北抬,使系统缓慢东移,影响系统长时间维持在陕西北部上空,是造成强降水持续的重要因素。

ANALYSIS OF RAINSTORMS ASSOCIATED WITH SIMILAR TRACK TROPICAL CYCLONES HAITANG (0505) AND BILIS (0604)

It is generally thought that the influence of comparable track typhoons is approximately similar, but in fact their wind and especially their rainstorm distribution are often very different. Therefore, a contrastive analysis of rainstorms by tropical cyclones (TCs) Haitang (0505) and Bilis (0604), which are of a similar track, is designed to help understand the mechanism of the TC rainstorm and to improve forecasting skills. The daily rainfall of TC Haitang (0505) and Bilis (0604) is diagnosed and compared. The result indicates that these two TCs have similar precipitation distribution before landfall but different precipitation characteristics after landfall. Using NCEP/GFS analysis data, the synoptic situation is analyzed; water vapor transportation is discussed regarding the calculated water vapor flux and divergence. The results show that the heavy rainfall in the Zhejiang and Fujian Provinces associated with Haitang (0505) and Bilis (0604) before landfall results from a peripheral easterly wind, a combination of the tropical cyclone and the terrain. After landfall and moving far inland of the storm, the precipitation of Haitang is caused by water vapor convergence carried by its own circulation; it is much weaker than that in the coastal area. One of the important contributing factors to heavy rainstorms in southeast Zhejiang is a southeast jet stream, which is maintained over the southeast coast. In contrast, the South China Sea monsoon circulation transports large amounts of water vapor into Bilis – when a water-vapor transport belt south of the tropical cyclone significantly strengthens – which strengthens the transport. Then, it causes water vapor flux to converge on the south side of Bilis and diverge on the north side. Precipitation is much stronger on the south side than that on the north side. After Bilis travels far inland, the cold air guided by a north trough travels into the TC and remarkably enhances precipitation. In summary, combining vertical wind shear with water vapor transportation is a good way to predict rainstorms associated with landing tropical cyclones.

The Influence of Typhoon Usagi on Shaoyang City

[Objective] The research aimed to study the influence of typhoon Usagi on Shaoyang in 2013. [Method] By using synoptic analysis, physical quantity diagnosis and Doppler radar, a rainstorm process caused by typhoon Usagi was analyzed. [ Result] Sufficient water vaper and strong ascending motion caused by high-altitude divergence were favorable conditions for rainstorm generation in Shaoyang. Uplifting effect of the terrain in Shaoyang was also one of favorable conditions for rainstorm generation in Shaoyang. [Conclusion] The research could provide reference for flood prevention and disaster reduction in Shaoyang area.

近60年黑龙江省台风暴雨统计及环流特征分析

使用台风最佳路径、黑龙江省83个国家基本气象站日降水量资料及NCEP NC再分析资料,对近60年黑龙江省台风活动规律、台风暴雨时空分布和环流形势及各物理量统计特征等进行分析。结果表明:2010年以后造成暴雨的台风个数增加,2015年之后台风暴雨强度持续增加,2020年达到最强。黑龙江省台风暴雨站次最多的时间是7月下旬至9月上旬。黑龙江省受台风影响出现暴雨的次数自东南向西北递减,暴雨次数多的站点一般与地形有关。将台风暴雨过程的高空环流形势分为3型8类,A型暴雨过程以台风环流降水为主,多数为稳定性降水,降水持续时间较长,B型和C型暴雨过程有较强冷空气参与,对流活跃,通常雨强较大。给黑龙江省带来大范围暴雨的环流形势有5类。以A-Ⅱ和C-Ⅰ两种环流形势出现的台风个数最多,A-Ⅱ和B-Ⅱ造成的暴雨范围最广。黑龙江省台风暴雨过程低空均有低涡活动;水汽主要来自日本海和黄渤海;低层辐合中心与暴雨区有较好的对应关系。A-Ⅱ类台风暴雨的各个物理量特征最突出(假相当位温和比湿略小于B-Ⅱ类);B-Ⅱ类台风暴雨过程的暖湿空气最强,尽管动力条件稍差,但较好的热力和水汽条件也足以造成大范围的暴雨天气,成为平均单个过程出现暴雨以上站次最多的类型。

Analysis on "96. 8" Heavy Rainstorm Process in Handan

[ ObjEtive] The research aimed to analyze ＂96.8＂ heavy rainstorm process causing flood disaster in Handan. [ Method] Based on ac- tual situation data, satellite cloud data and NCEP reanalysis data in the first dekad of August in 1996, ＂96.8＂ heavy rainstorm process causing flood disaster in Handan was analyzed to understand occurrence reason of the flood disaster. [ Result] Two meso-scale convective cloud clusters which developed and went north in turn caused ＂96.8＂ heavy rainstorm in Handan. Typhoon and inverted trough were main weather systems induced flood disaster in Handan. In going north process of the low-level jet, due to blocking of the subtropical high, water vapor and energy accumulated in Handan, providing material basis for formation of the heavy rainstorm. Development and eastward movement of the short-wave trough at middle lati- tude and continuous invasion of the reflux weak cold air at the low layer were direct reason for triggering generation and development of the convec- tive cloud cluster, and further causing continuous rainstorm. Wet layer over the rainstorm zone was deep and thick. Meridional distribution of the wet zone was wider than latitudinal distribution. South China Sea and Bay of Bengal were water vapor sources for the rainstorm zone. In the whole rain- storm period, it was convergence at low layer and divergence at high layer in the rainstorm zone. It was positive vorticity at low layer and negative vorticity at high layer. Precipitation intensity changed as convergence and divergence. Rainstorm zone had strong ascending motion. As strengthe- ning and uplifting of the ascending motion strong center, strong precipitation also strengthened. Rainstorm center was near the biggest vertical ve- locity center. Strong precipitation changed as vertical ascending motion. [ Conclmion] The research provided scientific basis for disaster prevention and reduction and decision-making service.

A Case Study of a Regional Torrential Rain in North China Caused by Typhoon Damrey (2012)

By using the NCEP/GFS analysis data, CIMISS data, JMA and China’s Typhoon Networks, heavy rainstorm occurred in east of North China associated with Typhoon Damrey from August 3rd to 4th, 2012 was analyzed. Results show during Damrey was going nearby Tianjin City and Hebei province of China, heavy rainstorm was observed in the cities of Qinhuangdao and Tangshan. The southerly jet stream from the southern side of the subtropical high and the periphery of Typhoon Saola is the conveyor belt for water vapor and energy, which enables Damrey to maintain for a long time and provide water vapor and heat conditions for rainfall in east of North China. The structure of Damrey caused a strong updraft in east of North China with a K-index greater than 35°C, which provided a favorable condition for the heavy rainstorm. The typhoon rainstorms in North China are the result of the interaction of the westerly, subtropical and tropical systems. In this heavy rain period, there was an obvious interaction between subtropical and tropical systems. This study has investigated the interaction between the northwestern Pacific typhoon and the North China heavy rainstorm, including the circulation characteristics of the typhoon and North China before and after the regional heavy rainstorm. Additionally, the climate background provides a reliable basis for the heavy rain forecast.

北上台风造成黑龙江省暴雨事件的气候特征

把北上台风影响黑龙江省且造成暴雨的天气过程定义为一个暴雨台风事件,根据影响的强度及方式分为3种类型:热带气旋型、变性型和水汽型。利用1981—2020年CMA最佳数据集和黑龙江省84个国家观测站常规观测资料进行分析,黑龙江省暴雨台风事件共有29个,均出现在7—9月,8月最多,9月最少。多数台风都在35°N以北登陆,其中在朝鲜半岛附近向东北移动入日本海的路径最多,由朝鲜半岛或者辽宁进入东北地区的路径次之。对比各类型发现,热带气旋型在暴雨站次、平均雨量等暴雨特征方面表现最强,变性型次之。研究中发现,暴雨台风事件具有明显的年代际特征,1995—2011年为弱影响期,1981—1994年和2012—2020年为2个强影响期,后一个强影响期中暴雨台风事件明显增多,年内时间跨度更大,暴雨站次、平均雨量等暴雨特征值更大,热带气旋型和变性型的影响系统更强,但路径差异不大。