辐合线

MαCS发生在低层切变线南侧的中尺度辐合线（或辐合中心）上，并在减弱阶段演变为明显的低涡结构；

The M α CS occurred over the mesoscale convergence line ( or convergence center ) located south of a shear line in the lower-level jet ( LLJ ) field during its occurrence and development and became a clear low vortex during its weakening and dissipative stage .

结果表明：该次大范围风雹强对流天气系统是在东北低涡下，高空前倾槽与地面辐合线有利的大环流背景下，一个中尺度对流系统MCS影响所致。

The result of the study indicated that this large area wind-hail strong convection weather system was aroused by one MCS and controlled by the northeast low vorticity . It was in advantaged large circumfluence background of upper-air pitch trough along with surface convergence line .

分析MCS在MCC西南方向传播的原因表明，两条辐合线的移动方向和速度决定了暴雨MCS的传播方向。

Analysis of causes as to why MCS propagates to the southwest of MCC indicates the propagation direction depends on the direction and velocity of the two convergences .

本文用Barnes带通滤波法、二十五点格式滤波法和高阶高通隐式滤波法，对含有地面辐合线和飑线的地面加密观测资料和客观分析资料进行了中尺度滤波试验。

In this paper , based on dense observational data of squall line and its objective analysis data the Barnes filter , the twenty-five points filter , and the high-order high-pass implicit filter are used for mesoscale filtering experiment .

分析结果表明，高空南支槽、地面辐合线、850hPa西南急流和切变线，是这次强对流天气过程的主要影响系统；

Results show , it is the principle influencing systems that the upper trough , surface convergence line , The low level southwest jet and shear line .

冷暖空气的激烈交锋、梅雨锋上的中尺度辐合线、700hPa、850hPa上的低涡、切变线以及稳定维持的高低空急流是导致这场暴雨的直接影响系统；

The strong conflict of warm and cold mass , mesoscale convergence on Meiyu front , shear line , and stably maintaining of high and low jets make for the rainfall .

使用MUSCAT技术对这次特大暴雨进行了双多普勒雷达三维风场反演，研究表明，中低层辐合线和中尺度气旋是造成此次暴雨的重要原因；

The three-dimensional wind of the heavy rain were retrieved by MUSCAT ( multiple-Doppler synthesis and continuity adjustment technique ) using the dual-Doppler radar volume scan data . It showed that the convergence line and the meso-cyclone at the low level play an important role in this heavy rain event .

地面辐合线与强对流天气落区

Surface Convergence Line and Precipitation Area Forecast of Heavy Convective

中尺度辐合线的产生对于区域性暴雨过程的产生具有重要作用；

The mesoscale convergence thread makes important effect on regional rainstorm forming .

得到基本的边界层辐合线。

Get the basic PBL convergent lines . 2 .

相对多雨带与低层流场辐合线有很好的对应关系。

The eastern rain-belts are closely related with low level flow convergence line .

辐合线的形成与大尺度背景和特定地形有关。

The formation of convergence lines is closely related to large - scale synoptic patterns and special topography .

本文主要完成了以下两部分工作：一、边界层辐合线的自动提取。

This paper has completed the following two parts : 1 . The automatic extraction of PBL convergent lines .

发现一个具有微冷锋特徵的辐合线是造成这次暴雨的主要中系统。

A mesoscale convergence line with some features of mini-cold front was a main system which caused the heavy rain .

干线与地面辐合线触发产生对流，是十分重要的触发系统。

The dry line and convergent line on ground surface contributed to convection which can be the important triggering system .

低层螺旋度大值中心轴线与切变线和地面倒槽辐合线走向一致，高层螺旋度与高空急流有关。

The axes of low-layer helicity plus center is concurrent with shear line and the convergence line of surface inversion trough .

在大尺度环流形势下，中尺度辐合线和地形作用为局地大暴雨提供了有利条件。

The large scale circulation situation , mesoscale convergence line and orographic action provided advantage condition for local large heavy rain .

强对流天气在速度场上表现为中尺度辐合线、风向风速辐合区、风速辐合区、大风区等中尺度系统。

It comes on with some mesoscale system , such as mesoscale convergence line wind shear , gale area and so on .

全年平均的赤道辐合线位于北纬5°左右。

TECHNOLOGY ON LINE The yearly average equatorial convergence zone is at about 5 ° N. From winter to summer all the three cells shift northward .

在强对流天气形成的前期，在天气系统中会存在着一些预示灾害的气象学特征&边界层辐合线。

In the early stage of formation of convective weather , the weather system will exist some characteristics of disasters , which were called PBL convergent lines .

采用空间带通滤波技术，对模拟结果进行尺度分离，揭示出对此次暴雨天气过程有直接影响的中尺度系统，即中尺度低压和中尺度辐合线；

The simulation result is scale-separated by spatial band-pass filtering , which reveals the mesoscale low pressure and convergence line that had direct impact on this rainfall process .

第2次初始对流是由午后的边界层辐合线触发的，从华北平原南下的浅薄冷空气也起了重要作用。

The second initial convections are arisen by boundary convergence lines in the afternoon , meantime the lower level cold air from Huabei Plain also contributes to their formation .

在风场比较复杂的区域，如中尺度辐合线等，两种方法反演的风向、风速差别较大。

The more wind fields is complex , for example the middle-scale convergence line , the bigger is the difference of the retrieved wind direction and speed between with two methods .

辐合线在反射率图上反映得较明显，一般呈现一种无规则的复杂的带状结构，通常无法直接使用常规的形状识别方法。

Convergence lines reflect clearly in the reflectivity picture , generally presenting a complex belt structure with no rule , which makes it impossible to use the conventional shape recognition method directly .

在短时预报系统中对强对流天气的预报有一个时间量的要求，我们需要在这个时间量的前提下，对一定时间区间的边界层辐合线都需要进行自动识别。

In the short-term forecasting system , there is time requirement for the strong convective weather forecast , under this amount of time , the convergence line need be automatically recognized in a certain time interval .

经综合分析表明：暴雨期间，在台风外围第二象限稳定的东风气流，并发生扰动，构成产生特大暴雨的中尺度东风辐合线天气系统。

The analysis indicates that the stable easterly stream provided by the second quadrant of the outside of the typhoon and its disturbance constitute the mesoscale easterly stream convergence line synoptic system which results in heavy rain .

整个过程中主要有三个强对流云团活动，地面对应有3个中-β尺度雨团产生，雨团一般出现在中尺度辐合线或中尺度气旋性环流偏向暖湿气流一侧；

There are three severe convective cloud clusters and three meso - β rain clusters during the heavy rainfall , and the rain clusters appeared on the mesoscale convergence line or the warm and moisture side of the mesoscale low .

利用高分辨率η坐标模式，以一个实际飑线个例的常规资料为初值，通过嵌入一定强度的边界中层尺度辐合线，进行了边界层辐合线型飑线激发的数值试验。

Based on the conventional data of a actual case of squall line and inserted certain intensity PBL convergence line , numerical trial of motivation of squall line of PBL convergence line type is made by using improved high resolution ETA model .

通过分析探空、地面加密自动站和闪电定位等资料进一步指出，地面中尺度辐合线、对流不稳定和地形抬升的共同作用，加剧了赣西南局地降雨的强度。

After analyzing more data of sounding , dense surface automatic Meteorological stations and lightening location , we find that common effects of surface mesoscale convergence line , convective instability and terrain uplifting make the intensity of rainfall increased in west-south of Jiangxi province .

当对流发展较强时演变为单一模态分布，即辐合线附近低层为正涡度辐合气流上升区，而高层为负涡度辐散气流下沉区。

But in the period of convective developing , it comes to single mode pattern , which is with positive vorticity , convergence and upward current in low level , but negative vorticity , divergence and downward current in upper level nearby the convergence line .