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投稿时间：2024-02-06 修订日期：2024-10-24
投稿时间：2024-02-06 修订日期：2024-10-24
中文摘要: 利用加密小球探空、野外地面加密观测站、ERA5再分析资料、临河新一代天气雷达等资料，对2022年7—8月内蒙古黄河河套地区由河套灌区与库布奇沙漠地表差异形成的边界层辐合线(BLCL）及其在对流触发中的作用进行了详细分析。结果表明：河套BLCL是由地表差异、边界层大气环流、复杂地形共同影响所形成，主要发生在河套灌区东南部的库布奇沙漠地区，长度在100～200 km，为浅薄系统，垂直厚度约为1000～1100 m。BLCL日变化明显，在12:00—17:00为高发时段，占80%。7—8月BLCL形成概率高达60%，且有39%的BLCL会触发对流。BLCL形成的预报指标为：河套灌区杭锦后旗较库布奇沙漠哈百来更的2 m气温低2.5℃以上、露点温度高6℃以上、相对湿度高20%以上；河套套内库布奇沙漠和毛乌素沙地区域为持续强劲的偏南风，地面10 m风速大值中心大于4 m·s-1；海平面气压场西低东高，黄河“几”字弯为等压线密集带，气压梯度达3～4 hPa·100 km-1。BLCL的形成对对流触发具有重要意义，表现为对流触发、加强、组织等作用，在不同的环境条件和天气系统叠加配置下会触发局地对流、有组织强对流，导致河套地区暴雨等天气。河套BLCL在这一特定地区的生成和对流触发作用，与河套地区降水自西向东急剧增多的分布特征关系密切。
Abstract:Based on dense ball sound data, dense field surface observation, ERA5 and the Linhe New Generation Weather Radar data, detailed analysis is conducted on the boundary layer convergence lines (BLCL) formed by the surface differences between the Hetao irrigation area and the Kubuqi Desert in Hetao Area of the Yellow River in July and August 2022, and also on the role of BLCL in convection triggering. The results indicate that the BLCL in the Hetao Area was formed by the combined influence of surface differences, boundary layer atmospheric circulation and complex terrain, and mainly occurred in the Kubuqi Desert which lies in the southeast of the Hetao irrigation area, and the length of BLCL ranged from 100 to 200 km. The BLCL was a shallow system with vertical thickness of approximately 1000 to 1100 m. The daily variation of BLCL was significant, with a high incidence from 12:00 BT to 17:00 BT, accounting for 80%. The probability of BLCL formation in July and August was as high as 60%, and 39% of BLCL could trigger convection. The prediction indicators about the formation of BLCL are as follows.The temperature in Hangjinhou Banner in Hetao irrigation area is 2.5 ℃ lower than that in Habailaigeng in Kubuqi Desert, with dew point temperature higher than 6℃ and relative humidity higher than 20%. Continuous strong southerly winds blow in the Kubuqi Desert and Mu Us Sandy Land in Hetao Area, with maximum wind of 10 m above the surface being stronger than 4 m·s-1. The sea level pressure is low in the west and high in the east. A dense isobaric zone is in the curved section of Yellow River and the pressure gradient is 3-4 hPa·100 km-1. The formation of BLCL is of great significance to the convection triggering in this area, which is manifested in convection triggering, strengthening, and organization. Under different environmental conditions and weather system superposition configurations, the BLCL could trigger local convection, organized severe convection, torrential rain in Hetao Area. The generation and convective triggering of Hetao BLCL in this specific area are closely related to the distribution characteristics of rapid increase in precipitation from west to east in Hetao Area.
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基金项目:国家自然科学基金重点项目(42030604)、内蒙古自治区自然科学技术重点研发和成果转化项目(2022YFSH0009）和内蒙古自治区科技成果转化专项资金项目(2021CG0047)共同资助
| 作者 | 单位 |
| 孙永刚 | 内蒙古自治区气候中心,呼和浩特 010051 |
| 孟雪峰 | 内蒙古自治区气象台,呼和浩特 010051 |
| 计燕霞 | 内蒙古自治区气象台,呼和浩特 010051 |
| 崔曲馨 | 北京大学物理学院,北京 100871 |
| 刘珂 | 内蒙古自治区气象台,呼和浩特 010051 |
| 云静波 | 内蒙古自治区气象台,呼和浩特 010051 |
| 姜雨蒙 | 内蒙古自治区气象台,呼和浩特 010051 |
引用文本：
孙永刚,孟雪峰,计燕霞,崔曲馨,刘珂,云静波,姜雨蒙,2025.河套地区边界层辐合线形成及其对流触发作用[J].气象,51(1):85-96.
SUN Yonggang,MENG Xuefeng,JI Yanxia,CUI Quxin,LIU Ke,YUN Jingbo,JIANG Yumeng,2025.Formation of Boundary Layer Convergence Lines in Hetao Area and Their Convection Triggering Effect[J].Meteor Mon,51(1):85-96.
孙永刚,孟雪峰,计燕霞,崔曲馨,刘珂,云静波,姜雨蒙,2025.河套地区边界层辐合线形成及其对流触发作用[J].气象,51(1):85-96.
SUN Yonggang,MENG Xuefeng,JI Yanxia,CUI Quxin,LIU Ke,YUN Jingbo,JIANG Yumeng,2025.Formation of Boundary Layer Convergence Lines in Hetao Area and Their Convection Triggering Effect[J].Meteor Mon,51(1):85-96.
