| 张玉荣,姚晓娟,白舜耀.1991-2020年河套灌区强对流天气主要流型及环境参量特征分析[J].沙漠与绿洲气象,2024,18(2):76~82 |
| 1991-2020年河套灌区强对流天气主要流型及环境参量特征分析 |
| Characterization of major flow patterns and environmental parameters of strong convective weather in the Hetao irrigation area from 1991 to 2020 |
| 投稿时间：2023-08-16 修订日期：2023-10-07 |
| DOI： |
| 中文关键词: 强对流天气,短时强降水,冰雹,物理量 |
| 英文关键词:convective weather, short-term heavy precipitation, hailstorm, physical quantities |
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| 摘要点击次数: 120 |
| 全文下载次数: 50 |
| 中文摘要: |
| 利用常规气象观测资料、区域自动站观测资料及ERA5 再分析资料对河套灌区 1991-2020年542个冰雹个例和281个短时强降水个例主要流型及局地要素特征进行分析。分析结果显示:1、短时强降水天气主要有西西伯利亚低槽(涡)、东北冷涡、蒙古冷涡、西南气流四类流型；冰雹天气主要有新疆低槽(涡)、东北冷涡、中亚低槽(涡)、新疆冷涡四类流型。2、河套灌区短时强降水和冰雹各关键参数预报阈值均有差异,最低阈值的建议值采用箱线图25％百分位值,其中分别为26℃和33℃；K指数均值分别为27 ℃和35 ℃；CAPE均值分别为515 J·kg-1和405 J·kg-1；0～6 km垂直风切变均为7×10-3ｓ-1；0℃层高度高度均值分别为4656 m和4069 m；-20℃层高度高度均值分别为8070 m和7054 m。3、冰雹需要更大的K指数、以及低层强暖空气；同时冰雹有更低的 0℃层高度和-20℃层高度,较低的0℃层高度可以防止冰雹下落过程融化；此外下垫面因子对不同强对流天气的影响程度不同,海拔高度是影响河套灌区冰雹分布的主要因素。 |
| 英文摘要: |
| Conventional meteorological observation data, regional automatic station observation data and ERA5 reanalysis data are used to analyze the main flow patterns and local element characteristics of 542 hail and 281 short-term heavy precipitation cases in Hetao Irrigation Area from 1991 to 2020. The analysis results show that: 1) there are mainly four types of flow patterns for short-term heavy precipitation in the West Siberian trough (vortex), Northeast cold vortex, Mongolian cold vortex, and southwestern airflow; and there are mainly four types of flow patterns for hailstorms in the Xinjiang trough (vortex), Northeast cold vortex, Central Asian trough (vortex), and Xinjiang cold vortex; 2) there are differences in the forecasting thresholds for each key parameter of short-term heavy precipitation and hailstorms in the Hetao irrigation area, and the lowest thresholds are suggested by using the box-and-line diagrams of the 25 percentile values, values of are 26 ℃ and 33 ℃, respectively; the mean values of K-index are 27 ℃ and 35 ℃, respectively; the mean values of CAPE are 515 J·kg-1 and 405 J·kg-1, respectively; the vertical wind shear from 0 to 6 km is 7×10-3s-1, respectively; the mean values of 0 ℃ layer heights are 4656 m and 4069 m, respectively; the mean values of -20 ℃ layer heights are 8070 m and 7054 m, respectively. 3) the forecast thresholds of short heavy precipitation and hail in the Hetao irrigation area are different. Hailstorms require a larger K index, as well as low-level strong warm air; at the same time, hailstorms have lower 0℃ layer heights and -20℃ layer heights, and lower 0℃ layer heights can prevent hailstorms from melting during the descent process; in addition, the degree of influence of the subsurface factor on different strong convective weather is different, and altitude is the main factor influencing the distribution of hailstorms in the Hetao irrigation area. |
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