淮河流域大别山地形对梅雨期暴雨低涡影响的模拟研究

基于淮河流域梅雨期低涡暴雨落区及低涡移动路径的统计特征,设计WRF数值模拟方案,研究大别山脉对浅薄低涡及其暴雨的地形强迫机制。结果表明:1)在三组数值试验中,无山脉时低涡东移速度较快,北绕山脉路径较慢,翻越山脉的移速居中;无大别山地形时,低涡路径明显偏南,显示低涡具有沿低地移动的特征;大别山地形倒置时,大尺度山体的出现迫使低涡北绕,路径更偏北。2)低涡反气旋式北绕,抵消和减弱了低涡强度;无山脉时,低涡强度由自身系统维持,强于北绕低涡;翻越山脊的低涡经历位涡守恒过程,山后强度几乎成倍增强。3)山脉梯度大,其强迫抬升作用大于低涡系统性抬升,两者叠加造成垂直上升速度增强近1倍。4)山后总涡度增强主要表现为低层涡度平流项、扭转项和散度项的明显增强,其增量可达1倍,但中层因子的影响不显著。5)强降水雨带发生在低涡偏东气流和偏南急流的汇合处,表明淮河流域暴雨低涡北部为强降水预警区。6)山脉通过对低涡东移路径的强迫,进一步影响暴雨强降水带的南北偏移。     

太行山东麓一次强对流降雹过程中的地形强迫

利用WRF模式对2011年5月26日发生在太行山东麓的一次强对流降雹过程进行数值模拟,探讨了太行山及周边地形在本次强对流过程的作用。结果表明,控制华北平原的偏东暖湿气流受太行山阻挡并与切变线东南侧的西南暖湿气流汇合,在太行山东侧形成水汽高值区。太行山东坡下垫面向上热通量明显高于华北平原,午后850hPa高度山坡与平原的假相当位温梯度达到0.2 K·km~(-1),850~600 hPa假相当位温垂直梯度达4 K·km~(-1),对应上坡风的垂直速度大于1 m·s~(-1),热力环流为太行山东麓对流的发生提供了动力条件。太行山东侧暖湿气层之上为偏西干冷气流,由此形成的强热力不稳定与水汽高值区、上坡风共同造成太行山东麓强对流过程的发生。局地小尺度地形抬升与重力波共同促使太原盆地有对流单体生成,该单体移经太行山西侧迎风坡受阻挡抬升而增强,越过山顶后与维持在太行山东侧的对流单体发生合并,从而导致对流云的强烈发展。     

2019年6月下旬中昆仑山北坡两场强降水对比分析

利用常规气象探测资料、NECP和EC高时空分辨率再分析资料,对2019年6月25日和28日出现在中昆仑山北坡两场强降水过程进行分析。表明：25日过程范围大、持续时间长的强降水,28日为分散、对流性强降水;两场天气过程影响系统有高空急流、中层低值系统、低层辐合线;25日强降水系统移动缓慢、冷空气从东西两侧进入昆仑山北坡,同时西太副高西侧西南风将大量水汽输送至昆仑山北坡,低层存在偏东和偏北、偏西风辐合;28日强降水低值系统移动迅速、对流层有逆温和不稳定,午后升温和低层弱辐合、山前偏北风是对流触发条件。中高层偏西偏南风水汽输送至昆仑山北坡上空,在低层合适的风场将水汽输送汇集到昆仑山北坡是强降水的关键,25日水汽输送强度和厚度明显强于28日。地形对于降水作用表现在热力和动力两方面。     

地形作用下低空急流的演变与强降水对流风暴系统的相互作用

利用雷达、卫星、风廓线雷达和地面加密区域自动气象站等观测资料,分析了2016年入梅后发生在鄂东地区一次极端强降水事件的中尺度对流系统发生发展过程、结构演变及其传播特征,旨在揭示造成强降水过程中的3个中尺度对流系统（MCS）的触发、发展、维持机理以及它们之间内在的中尺度动力学关系,尤其是地形作用下的低空急流的演变与强降水对流风暴系统相互作用过程。研究表明:（1）与大多数梅雨锋上的强降水带与低空切变线平行分布不同,此次极端强降水雨带呈倾斜的“n”字形,其中两条主雨带近乎与低空切变线垂直;此次极端强降水分别由大别山迎风坡上西北—东南向MCS、湖北中东部平原地区西北—东南向MCS和桐柏—大洪山东侧东北—西南向MCS造成。3个MCS移动缓慢,都具有后向传播的特征。（2）大别山迎风坡上MCS初始雷暴是低空急流下边界不断向下扩展过程中在地形抬升作用下触发的,而湖北中东部平原地区的MCS和桐柏—大洪山东侧MCS的触发、发展、加强都与大别山迎风坡上MCS形成的冷池加速推进形成的出流边界与环境气流形成的强烈辐合抬升作用有关。（3）垂直于大别山的边界层西南急流对山坡上的对流冷池产生的顶托作用不仅平衡了冷池密度流产生的向下作用力,而且进一步强化了山区的辐合抬升强度,使得大别山迎风坡上强降水风暴系统得以长时间维持和发展;当山坡上的对流冷池堆积到足够厚度,或者由于低空急流的下边界迅速抬升时,这种平衡被打破,大范围的冷池俯冲下山并在平原地区快速推进,造成了湖北中东部平原地区大范围的雷暴大风和MCS发展加强,并沿冷池前沿逐步组织化,形成平原地区东南—西北向的强降水带。      

Orographical modification and large scale forcing of a cold front

Summary The development of a cold front influenced by orography and large scale forcing is examined with a two-dimensional meso-scale model. The model is based on the primitive equations and uses the hydrostatic and anelastic approximations. Gradients of the basic flow and temperature field in the third dimension are taken into account during the simulations. Low diffusive numerical schemes and radiation boundary conditions reduce the numerical errors to an acceptable minimum for a two day simulation and avoid reflections at the upper and lateral boundaries. Frontogenetical forcing is included in the simulations by specifying either a vertically sheared or horizontally convergent basic zonal flow field. Model runs with an idealized cold front were carried out over flat terrain and in the presence of a bell shaped mountain ridge.The simulations show a weakening of the cold front on the windward side of the mountain ridge and a strong reintensification on the leeward side relative to the control runs without topography. Analysis of frontogenesis terms demonstrates the importance of convergence in the ageostrophic circulation and of along-front temperature advection for the development of the cold front. The strong intensification of the cold front on the leeward side of the mountain ridge can only partly be explained by superposition with the mountain induced wave. It is mainly caused by ageostrophic deformation forcing in the strong downward flow of this wave.The results also show that the cold front passage over the mountain ridge is not a continuous process. The formation of a new frontal structure on the leeward side of the mountain ridge, well separated from the primary one, is observed while the initial cold front still exists in the upslope region. Generally nonlinear interactions between the mountain wave and the cold front are the important mechanisms to explain these phenomena.With 18 Figures     

Mesoscale modeling study of severe convection over complex terrain

Short squall lines that occurred over Lishui, southwestern Zhejiang Province, China, on 5 July 2012, were investigated using the WRF model based on 1°× 1° gridded NCEP Final Operational Global Analysis data. The results from the numerical simulations were particularly satisfactory in the simulated radar echo, which realistically reproduced the generation and development of the convective cells during the period of severe convection. The initiation of this severe convective case was mainly associated with the uplift effect of mesoscale mountains, topographic convergence, sufficient water vapor, and enhanced low-level southeasterly wind from the East China Sea. An obvious wind velocity gradient occurred between the Donggong Mountains and the southeast coastline, which easily enabled wind convergence on the windward slope of the Donggong Mountains; both strong mid–low-level southwesterly wind and low-level southeasterly wind enhanced vertical shear over the mountains to form instability; and a vertical coupling relation between the divergence on the upper-left side of the Donggong Mountains and the convergence on the lower-left side caused the convection to develop rapidly. The convergence centers of surface streams occurred over the mountain terrain and updrafts easily broke through the lifting condensation level(LCL) because of the strong wind convergence and topographic lift, which led to water vapor condensation above the LCL and the generation of the initial convective cloud. The centers of surface convergence continually created new convective cells that moved with the southwest wind and combined along the Donggong Mountains, eventually forming a short squall line that caused severe convective weather.     

条件不稳定大气中二维小尺度双脊地形上空对流及降水特征

在条件不稳定大气条件下,二维小尺度双脊钟形地形上空对流触发、传播和降水分布特征主要决定于地形上游基流强度、双脊地形配置形式、地形高度及其山谷宽度。双脊地形在沿基流方向上有两种配置:高脊地形位于上游和低脊地形位于上游。对于高脊地形位于上游的双脊地形,上游高地形将起主导作用,山地上空对流及降水特征与单脊地形类似。对于低脊地形位于上游的双脊地形,上游低地形可明显地改变下游高地形的前方来流,同时,下游高地形也能够对上游低地形背风侧流动产生影响,从而导致出现地形上空复杂的对流传播、降水分布特征。对于低脊地形位于上游的双脊地形,其山谷宽度主要决定了双脊地形与单脊地形之间在对流、降水分布等的差异;当山谷宽度较小时,双脊地形可以近似为一个包络地形,此时地形上空的对流、降水特征与单脊地形类似;当山谷宽度较大时,双脊上空流动相互影响较小,此时双脊地形可以分成两个单脊地形;当山谷宽度在一定范围内,其上空的对流及其降水分布与单脊地形有明显差异。对于低脊地形位于上游、中等山谷宽度的双脊地形上空降水主要呈现4种类型:(1)山谷与低脊迎风坡降水;(2)高脊迎风坡降水;(3)低脊山峰与高脊迎风坡降水;(4)低脊背风侧、双脊山峰准静止降水。     

An Analysis of a Meso-β System in a Mei-yu Front Using the Intensive Observation Data During CHeRES 2002

The conventional and intensive observational data of the China Heavy Rain Experiment and Study (CHeRES) are used to specially analyze the heavy rainfall process in the mei-yu front that occurred during 20-21 June 2002, focusing on the meso-β system. A mesoscale convective system (MCS) formed in the warm-moist southwesterly to the south of the shear line over the Dabie Mountains and over the gorge between the Dabie and Jiuhua Mountains. The mei-yu front and shear line provide a favorable synoptic condition for the development of convection. The GPS observation indicates that the precipitable water increased obviously about 2 3 h earlier than the occurrence of rainfall and decreased after that. The abundant moisture transportation by southwesterly wind was favorable to the maintenance of convective instability and the accumulation of convective available potential energy (CAPE). Radar detection reveals that meso-β and -γ systems were very active in the Mα CS. Several convection lines developed during the evolution of the MαCS, and these are associated with surface convergence lines. The boundary outflow of the convection line may have triggered another convection line. The convection line moved with the mesoscale surface convergence line, but the convective cells embedded in the convergence line propagated along the line. On the basis of the analyses of the intensive observation data, a multi-scale conceptual model of heavy rainfall in the mei-yu front for this particular case is proposed.     

An Analysis of a Meso-β System in a Mei-yu Front Using the Intensive Observation Data During CHeRES 2002

The conventional and intensive observational data of the China Heavy Rain Experiment and Study (CHeRES) are used to specially analyze the heavy rainfall process in the mei-yu front that occurred during 20-21 June 2002, focusing on the meso-β system. A mesoscale convective system (MCS) formed in the warm-moist southwesterly to the south of the shear line over the Dabie Mountains and over the gorge between the Dabie and Jiuhua Mountains. The mei-yu front and shear line provide a favorable synoptic condition for the development of convection. The GPS observation indicates that the precipitable water increased obviously about 2-3h earlier than the occurrence of rainfall and decreased after that. The abundant moisture transportation by southwesterly wind was favorable to the maintenance of convective instability and the accumulation of convective available potential energy (CAPE). Radar detection reveals that meso-β and -γ systems were very active in the MαCS. Several convection lines developed during the evolution of the MαCS, and these are associated with surface convergence lines. The boundary outflow of the convection line may have triggered another convection line. The convection line moved with the mesoscale surface convergence line, but the convective cells embedded in the convergence line propagated along the line. On the basis of the analyses of the intensive observation data, a multi-scale conceptual model of heavy rainfall in the mei-yu front for this particular case is proposed.     

Observational Study of Surface Wind along a Sloping Surface over Mountainous Terrain during Winter

The 2018 Winter Olympic and Paralympic Games will be held in Pyeongchang, Korea, during February and March. We examined the near surface winds and wind gusts along the sloping surface at two outdoor venues in Pyeongchang during February and March using surface wind data. The outdoor venues are located in a complex, mountainous terrain, and hence the near-surface winds form intricate patterns due to the interplay between large-scale and locally forced winds. During February and March, the dominant wind at the ridge level is westerly; however, a significant wind direction change is observed along the sloping surface at the venues. The winds on the sloping surface are also influenced by thermal forcing,showing increased upslope flow during daytime. When neutral air flows over the hill, the windward and leeward flows show a significantly different behavior. A higher correlation of the wind speed between upper-and lower-level stations is shown in the windward region compared with the leeward region. The strong synoptic wind, small width of the ridge, and steep leeward ridge slope angle provide favorable conditions for flow separation at the leeward foot of the ridge. The gust factor increases with decreasing surface elevation and is larger during daytime than nighttime. A significantly large gust factor is also observed in the leeward region.     

A High-Resolution Modeling Study of the 19 June 2002 Convective Initiation Case during IHOP 2002: Localized Forcing by Horizontal Convective Rolls

The initiation processes of one of the initial convective cells near and on the east side of a dryline on 19 June 2002 during the IHOP 2002 field experiment in the central United States is analyzed in detail based on a high-resolution numerical simulation. Prominent horizontal convective rolls and associated near-surface moisture convergence bands [called roll convergence bands(RCBs) here] develop within the convective boundary layer(CBL) due to surface heating, in the hours leading to convective initiation(CI). The RCBs east of the dryline are advected toward the primary dryline convergence boundary(PDCB) by the southerly moist flow as the CBL deepens with time. Backward trajectories of air parcels forming the initial precipitating updraft of the convective cell are found to primarily originate at about 1–1.5 km above ground, within the upper portion of the shallower CBL earlier on. The representative air parcel is found to follow and stay on top of a surface RCB as the RCB moves toward the PDCB, but the RCB forcing alone is not enough to initiate convection. As this RCB gets close to the PDCB, it moves into a zone of mesoscale convergence and a deeper CBL that exhibits an upward moisture bulge associated with the PDCB. The combined upward forcing of the RCB and the mesoscale PDCB convergence quickly lifts the representative air parcel above its level of free convection to initiate convection. A conceptual model summarizing the CI processes is proposed.     

浙江天目山背风坡对流触发个例的对比分析

针对夏季副热带高压背景下浙北天目山附近的强对流天气个例,利用中尺度实况资料,分析了天目山对触发对流的作用。结果表明:浙江省夏季位于副热带高压边缘时,低层处于西南背景风时,在低Froude数条件下,气流经过黄山、天目山后在背风侧形成一段辐合线,在有利的热力条件配合下,容易触发对流。山地的热力强迫作用使地形上空新生了很多积云,积云分布基本与地形一致。同时,天目山背风侧出现一条积云线,其形成的原因是天目山背风侧辐合线的辐合抬升作用。背风侧辐合线尺度有几十千米,方向随环境风向转变。对流触发的位置位于这条辐合线上靠近山地的一端。这可能是由于山地热力强迫作用产生的积云移到辐合线上继续发展产生对流云,即山地的动力和热力作用共同触发了对流。     

登陆台风Matmo(2014)北侧对流雨带的触发和发展过程

登陆台风Matmo（2014）北侧弱回波区突发多条强对流雨带,造成严重影响。本文利用NECP/NCAR的FNL（Final）再分析资料,地面自动站加密观测资料、雷达拼图资料等对台风北侧连续出现的3条对流雨带的触发和发展过程进行研究。结果表明:初始对流是在弱的对流不稳定和条件对称不稳定条件下,由锋面强迫和地形抬升作用共同触发。接二连三发生的3条对流雨带是在台风北部高湿环境,长时间稳定的水汽辐合,明显的对流不稳定,局部弱条件对称不稳定条件下,由近地面辐合线在辐合稳定并加强后触发的,有利的环境和多层不稳定的叠加有利于雨带的发展和维持。先后触发对流雨带的3条辐合线在发生位置上相当接近。辐合线的形成一方面由海陆下垫面差异、江苏和山东南部海岸线曲率、台风风速随半径分布特点所决定;另一方面,辐合线2和3的形成还与它们北侧对流雨带的冷出流密切相关。对流带上的强降水中心往往对应着稳定的辐合中心,辐合中心主要位于风速大小梯度明显的位置上。而辐合线上的风速梯度主要受海岸线、地形附近的降水分布影响。     

中亚低涡背景下阿克苏地区一次强降水天气分析

为了加强对新疆暴雨过程的中尺度系统发展机理的认识,利用美国环境预测中心的FNL、欧洲中期数值预报中心的全球再分析资料、中国气象局提供的地面自动气象站观测资料、中国国家卫星气象中心提供的卫星辐射亮温（TBB）资料及WRF高分辨率数值模拟对2013年6月17—18日发生在新疆阿克苏地区的一次暴雨天气过程进行分析。结果表明,此次降水过程是发生在中高纬度“两脊一槽”的环流形势下,中亚低涡为这次暴雨的发生提供了有利的天气尺度动力及水汽条件;中亚低涡环流与天山南脉特殊地形造成的气流绕流叠加生成的中尺度辐合线是此次强降水的重要中尺度影响系统,山谷地形热力性质差异造成的下坡风推动辐合线移动,辐合线上发展的强对流引发了阿克苏地区的强降水。WRF模拟结果能够基本再现本次天气过程的降水落区、强度以及风场演变等。结合观测以及模拟资料进行的初步分析显示,西天山的阻挡导致偏南风在西天山南坡山谷附近产生堆积和辐合,山谷附近有局地的地形辐合线形成。同时,随着大尺度环流形势的调整,中亚低涡移动至阿克苏地区附近后,低涡南部的偏西气流一部分直接越过西天山变为西北风,另一部分穿过伊犁河谷转为东北风,这两支气流共同加剧了天山南脉阿克苏地区的偏北气流,促进了西天山南坡山谷附近中尺度辐合线的加强。辐合线以东的偏东气流带来的水汽在天山南脉前堆积,随着夜间山谷下坡风的增强作用,中尺度辐合线在向东南方向推进过程中不断发展加强,配合山脚堆积的水汽和辐合抬升,不稳定能量释放,对流发展,为阿克苏地区带来强降水天气。      

2020年8月10日四川芦山夜发特大暴雨的动热力 结构及地形影响

由特殊喇叭口地形促成的四川雅安暴雨久已有名,研究颇多,而这一地区的暖区暴雨、夜发性暴雨的研究在业务预报和防灾减灾迫切需求的推动下也应加强。利用ERA5再分析资料,结合地面加密观测资料及中国气象局信息中心提供的三源融合近实时降水资料,对造成2020年8月10日四川雅安芦山的特大暴雨过程的动热力结构演变、触发机制和地形影响进行了诊断分析,揭示了弱天气尺度强迫及特殊地形影响背景下暖区暴雨的水汽、动热力结构演变及触发机制。研究得出:（1）此例暴雨属于500 hPa无明显影响系统、低层无急流背景下的东南风型暖区暴雨。在雅安“迎风坡”、“喇叭口”地形和芦山西南向“?”型峡谷地形的影响下,配合西太副高西进、东南暖湿气流加强和850 hPa弱低涡辐合气流的共同作用而诱发产生,此次降水时间短,强度大。（2）降水开始到强盛期间,始终有边界层地形作用产生的抬升速度、气旋式涡度和水平辐合与系统性垂直上升运动、涡度和散度叠加,增强了低层辐合,加剧了垂直上升运动,促使降水加强。（3）差动θ_se平流使得暴雨区对流不稳定度增强。对流抑制能量为零的高能高湿环境中,500 hPa θ_se弱冷平流也是暖区暴雨触发的因素之一;傍晚地形冷平流触发了初始对流并沿海拔高度1500米地形线分布;暴雨区上游强降水造成雷暴冷池出流叠加山风在“?”型峡谷西侧形成γ中尺度辐合线,并移至“?”型谷地内维持;冷性气流在快速下山后亦以冷池形式维持在“?”型峡谷东侧山脉附近,形成强温度梯度,这些因素触发并维持了芦山夜间特大暴雨。     

1998年夏季副热带高压的短期结构特征及形成机制

通过对 1998年 7月副热带高压短期结构及其演变的诊断 ,指出 5 0 0hPa西太平洋副热带高压内并非均一的下沉运动 ,而是多处、多时存在上升运动 ,这是由西太平洋副热带高压的复杂的动力和热力性所决定。诊断还发现 ,在西太平洋副热带高压脊区下方的近地面层 ,多存在一个辐散下沉层 ,这是副热带高压内天气一般多晴空或少云的主要原因。利用动力学理论 ,研究副热带高压的复杂结构的成因 ,指出在 5 0 0hPa副热带高压的西部 ,高低空风场的分布决定了该区域必然多上升运动 ;高空强负涡度平流的存在是副热带高压内出现下沉运动的主要强迫机制     

Mechanism of a torrential rainstorm that occurred to the west of a Mei-yu frontal low

Heavy rainfall usually occurs to the southeast of a Mei-yu frontal low. The rainstorms appeared to the west of Mei-yu frontal lows are difficult to forecast because their formation mechanisms are not well understood. An extreme rainfall event occurred to the west of a Mei-yu frontal low in Anqing City, Anhui Province, China, on 13 July 2010, which was not well predicted. Based on observation data, NCEP/NCAR reanalysis data and high-resolution numerical simulation output, the mechanisms of this severe rainstorm are analyzed in this paper. The results indicate that the eastward moving meso-α-scale low was a key synoptic system that resulted in the formation of the mesoscale convective system causing the rainstorm. As the low moved eastward and strengthened, the increasing northerly flow and the southerly warm/moist flow formed an eastwest elongated convergence line (frontal zone) at the west part of the low. While the low moved to the coastal region, its intensity was enhanced and its moving speed was reduced. As a result, the convergence line and the frontal zone remained quasi-stationary near Anqing. Furthermore, Anqing is located in a valley between the Dabie and Wannan Mountains; the northerly winds flowed around Dabie Mountains and entered the valley, leading to an intense local convergence and frontogenesis near Anqing. Under the unstable environments with sufficient water vapor, the local intense frontogenesis along with intense convergence triggered and maintained the quasi-stationary mesoscale convective system that resulted in the record-breaking rainfall in Anqing.     

地形追随垂直运动方程在南疆极端暴雨中的诊断分析

针对2021年6月15～17日发生在昆仑山脉北坡的南疆极端暴雨过程,本文综合考虑地形对暴雨发生、发展的作用后,利用地形追随坐标控制方程并采用Boussinesq近似推导建立了地形追随坐标的非静力平衡广义垂直运动方程。诊断结果表明,经向气压梯度力耦合经向散度项（项一）、垂直气压梯度力耦合纬向散度项（项二）和非绝热加热经向梯度项（项三）是激发暴雨垂直运动发展演变的三个主要强迫项。项一体现了偏北风逐渐增强,在昆仑山脉的阻挡下导致经向辐合增强,触发了垂直上升运动。经向气流辐合始终是对流活动最主要的强迫过程,其次为纬向气流辐合。在地形追随坐标形式下,经向和垂直气压梯度能够增强项一和项二。对流发展阶段,水汽辐合与非绝热加热过程增强了非绝热加热经向梯度,促进了垂直上升运动发展。在地形的影响下,对流层中高层西风过山气流波动特征明显。重力波活动导致的高层辐散进一步促进了山脉迎风坡对流活动。经向和纬向气流辐合、非绝热加热过程以及重力波活动等多个因素共同造成了此次南疆极端暴雨。     

桂北山区两次突发性大暴雨触发及维持机制分析

利用常规观测资料、区域自动站资料、柳州多普勒雷达资料以及ERA5再分析资料对2020年6月24日(“6·24”过程)和7月9日(“7·9”过程)广西柳州元宝山地区先后出现的突发性局地大暴雨过程进行了分析, 探讨这两次过程的触发因子。结果表明: 在低层偏南暖湿气流持续输送的前提下, 元宝山脉动力抬升进一步增强了山脉附近垂直上升运动; 白天大量积聚的能量导致热力条件非常不稳定, 地面中尺度辐合线及局地地形形成的中尺度辐合中心和大尺度环流的配合致使对流系统先在元宝山脉南侧触发起来, “列车效应”以及高效率、低质心的降雨系统使得小时雨强和累积雨量极大; 两次过程与850 hPa西南气流风速脉动密切相关, 高温高湿的暖湿气流在元宝山地区强烈辐合为暴雨增幅提供了有利条件, 有利于强降水在柳州北部地区维持; “6·24”过程近地层有弱冷空气侵入, 低层水汽饱和、中高层有干冷空气卷入; “7·9”过程近地层没有冷空气侵入, 湿层深厚, 整层为高温高湿的环境。     

Study on the Formation Mechanism and Microphysical Characteristics of WarmSector Convective System with Multiple-Rain-Bands Organizational Mode

Based on ERA5 reanalysis data and multi-source observations, including polarimetric radar and automatic weather stations, this study analyzes the formation mechanism and microphysical characteristics of a warm-sector heavy rainfall event caused by a convective system with multiple-rain-bands organizational mode over the western coast of south China. In the early stage, under the influence of coastal convergence and topography, convection was triggered in the coastal mountainous areas and moved n...