| 雅安一次极端强降水的超级单体风暴特征及成因分析 |
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| 作者姓名： | 邱双 |
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| 作者单位： | 雅安市气象局 |
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| 摘 要： | 2020年8月10日-11日雅安市出现了一次区域大暴雨天气过程，其中芦山县出现了特大暴雨，此次特大暴雨天气过程，持续时间长，最大累积降水量、最大小时雨强较大，均突破了历史极值，具有较强的极端性。通过分析雷达回波可知，此次极端强降水由强降水超级单体风暴的稳定少动造成，本文根据雅安市365个区域自动站雨量数据、micaps实况资料、雷达以及NCEP 1°×1°再分析资料等资料，分析其产生的原因：（1）行星尺度和天气尺度系统稳定少动，低层夜间低层急流发展，输送暖湿平流，有利于对流不稳定层结的建立，为强降水超级单体风暴的发生提供了有利的环流条件。（2）地面到低层的假相当位温异常偏高，有利于对流不稳定的进一步发展，在强对流风暴附近还存在中尺度的假相当位温的密集区，锋区的动力强迫生成的次级环流有利于低层不稳定能量和水汽向高层输送，同时也触发不稳定能量的释放，产生较强的上升运动。（3）强的垂直风切变以及大的对流有效位能有利于强降水超级单体风暴的发生和维持其有组织的程度。（4）水汽条件异常也是此次强降水超级单体风暴的重要原因。（5）极端的高能高湿的大气状态下，边界层的中尺度辐合线是触发此次强降水超级单体风暴的直接原因，并且受地形的阻挡作用，强降水超级单体稳定少动，造成了此次极端强降水的发生。
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| 关 键 词： | 强降水超级单体风暴 对流不稳定 强的垂直风切变 中尺度辐合线 |
| 收稿时间： | 2021/2/22 0:00:00 |
| 修稿时间： | 2021/9/24 0:00:00 |
An Analysis of the Characteristics and Causes ofan Extremely Heavy Rain in Ya"an |
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| Authors: | Qiu Shuang |
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| Institution: | Ya''an Meteorological Bureau,Ya''an,625000 |
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| Abstract: | From August 10th to 11th, 2020, there was a regional heavy rainstorm in Ya''an City. Among them, Lushan County saw a heavy rainstorm. The heavy rainstorm lasted a long time, and the maximum accumulated precipitation and maximum hourly rainfall were relatively large. All have broken through historical extremes and have strong extremes. Through the analysis of radar echo, it can be known that the extreme heavy precipitation was caused by the stable and low movement of the heavy precipitation supercell storm. This article is based on the rainfall data of 365 regional automatic stations in Ya''an City, micaps live data, radar, and NCEP 1°×1°. Analyze data and other data to analyze the reasons for its occurrence: (1) The planetary scale and weather scale systems are stable and less moving, and the low-level night and low-level jets develop and transport warm and wet advections, which are conducive to the establishment of unstable convective stratification, which is a super unit of heavy precipitation. The occurrence of physical storms provides favorable circulation conditions. (2) The pseudo-equivalent potential temperature from the ground to the lower layer is abnormally high, which is conducive to the further development of convective instability. There are also dense areas of meso-scale pseudo-equivalent potential temperature near the strong convective storm. The level circulation is conducive to the transport of unstable energy and water vapor from the lower layer to the upper layer, and it also triggers the release of unstable energy, resulting in a strong upward movement. (3) Strong vertical wind shear and large convective effective potential are beneficial to the occurrence of heavy rainfall supercell storms and the maintenance of their organized degree. (4) Abnormal water vapor conditions are also an important reason for the heavy rainfall supercell storm. (5) Under extreme high-energy and high-humidity atmospheric conditions, the mesoscale convergence line of the boundary layer triggered the direct cause of the heavy precipitation supercell storm, and the heavy precipitation supercell is stable and less moving due to the blocking effect of the terrain. This resulted in the occurrence of this extremely heavy precipitation. |
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| Keywords: | extreme high energy and high humidity train effect heavy rainfall super cell storm |
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