A thunderstorm that produced severe wind, heavy rain and hail on 23 August 2001 in Beijing was studied by a three-dimensional cloud model including hail-bin microphysics. This model can provide important information f...A thunderstorm that produced severe wind, heavy rain and hail on 23 August 2001 in Beijing was studied by a three-dimensional cloud model including hail-bin microphysics. This model can provide important information for hail size at the surface, which is not available in hail parameterization cloud models. The results shows that the cloud model, using hail-bin microphysics, could reasonably reflect the storm＇s characteristics such as life cycle, rainfall distribution and the diameter of the hailstones and also can reproduce developing processes of downbursts, where they can then be compared with the observed features of the storm. The downburst formation mechanism was investigated based on the cloud microphysics of the simulated storm and it was found that the downburst was primarily produced by hail-loading and enhanced by cooling processes that were due to hail melting and rain evaporation. The loading and melting of hail played crucial roles in the formation of downbursts within the storm.展开更多
2015年7月29日浙江出现大范围冰雹和雷雨大风,影响范围、强度远超各级台站预判。利用地面气象站、区域自动站、FY-2G红外云图、多普勒雷达产品、NCEP(1°×1°)分析资料,对该过程进行综合分析。结果表明:1)由多单体风暴组...2015年7月29日浙江出现大范围冰雹和雷雨大风,影响范围、强度远超各级台站预判。利用地面气象站、区域自动站、FY-2G红外云图、多普勒雷达产品、NCEP(1°×1°)分析资料,对该过程进行综合分析。结果表明:1)由多单体风暴组成、位于高层东风波槽前的中尺度对流复合体是本次大范围强对流天气过程的直接制造者。2)中等偏弱的垂直风切变、上干下湿的水汽垂直分布及东风波西进叠加于低层暖区之上形成强不稳定层结是多单体风暴发生发展的有利环境背景。3)热带东风急流和高层东风波形成的辐散抽吸、近地面非绝热加热升温、地形抬升和边界层辐合线为对流发生发展提供有利动力抬升和对流触发条件。4)逆风区的出现、发展和控制与雹暴单体强度的发展、维持和减弱阶段有很好的对应关系。脉冲风暴单体中层径向气流辐合与核心反射率因子的下降对地面大风预报存在2个体扫的时间提前量。5)东风波系统以动能转换的方式为本次对流天气过程中的中尺度系统发展提供动能补给。6)加强500 h Pa以上中高层东向系统的监测和雷达产品短临实时监测,可提高此类对流过程预报的时间提前量。展开更多
基金supported by the Basic Scientific Program of the Institute of Atmospheric Physics supporting the 14th Five-Year Plan[Grant No.7-224151]Youth Innovation Team of China Meteorological Administration[Grant No.CMA2023QN10]+4 种基金the National Natural Science Foundation of China[Grant Nos.42175010,41965010,U223321842275010]Beijing Municipal Science and Technology Commission[Grant No.Z221100005222012]the Department of Science and Technology of Hebei Province[Grant No.22375404D]the Open subjects of the Key Open Laboratory of Cloud Physical Environment,China Meteorological Administration[Grant No.2020Z00715]。
基金This research was jointly sponsored by the National Natural Science Foundation of China （Grant Nos. 40575003 and 40333033） the Chinese Academy of Sciences Innovation Foundation （Grant No. KZCX3-SW-213 and KZCX3-SW-225）.
文摘A thunderstorm that produced severe wind, heavy rain and hail on 23 August 2001 in Beijing was studied by a three-dimensional cloud model including hail-bin microphysics. This model can provide important information for hail size at the surface, which is not available in hail parameterization cloud models. The results shows that the cloud model, using hail-bin microphysics, could reasonably reflect the storm＇s characteristics such as life cycle, rainfall distribution and the diameter of the hailstones and also can reproduce developing processes of downbursts, where they can then be compared with the observed features of the storm. The downburst formation mechanism was investigated based on the cloud microphysics of the simulated storm and it was found that the downburst was primarily produced by hail-loading and enhanced by cooling processes that were due to hail melting and rain evaporation. The loading and melting of hail played crucial roles in the formation of downbursts within the storm.
文摘利用多普勒雷达资料,结合探空和常规资料,对2 0 1 1年4月1 7日一次超级单体雹暴的流场和回波结构演变特征进行了详细研究,主要结果:该雹暴是在条件性不稳定和垂直风切变较大的环境条件下产生的右移风暴。雹云初生发展阶段,垂直剖面显示逐渐形成有组织化的斜上升气流促进雹云发展。成熟降雹阶段,雹云内形成一支强的斜上升气流和深厚的中气旋,主上升气流对应雹云的弱回波区。雹云维持典型的弱回波区—悬挂回波—回波墙特征结构。根据雷达径向速度和雹云移速订正得出的"零线"演变发现,随着雹云的发展,"零线"逐渐向悬挂回波靠近,并穿过悬挂回波,"零线"的走向为上翘式,附近"穴道"的汇集力较强,有利于降雹。通过对"零线"位置的判断可分析有利成雹的区域。根据高低空两层强回波的水平错位,利用两高度强中心连线所作剖面能快速准确得出特征剖面,并将0°C层以上6 k m高度处降雹潜势达到1 0 0%的4 5 d B Z的区域识别为成雹区,与降雹实况对比发现识别效果良好。
文摘2015年7月29日浙江出现大范围冰雹和雷雨大风,影响范围、强度远超各级台站预判。利用地面气象站、区域自动站、FY-2G红外云图、多普勒雷达产品、NCEP(1°×1°)分析资料,对该过程进行综合分析。结果表明:1)由多单体风暴组成、位于高层东风波槽前的中尺度对流复合体是本次大范围强对流天气过程的直接制造者。2)中等偏弱的垂直风切变、上干下湿的水汽垂直分布及东风波西进叠加于低层暖区之上形成强不稳定层结是多单体风暴发生发展的有利环境背景。3)热带东风急流和高层东风波形成的辐散抽吸、近地面非绝热加热升温、地形抬升和边界层辐合线为对流发生发展提供有利动力抬升和对流触发条件。4)逆风区的出现、发展和控制与雹暴单体强度的发展、维持和减弱阶段有很好的对应关系。脉冲风暴单体中层径向气流辐合与核心反射率因子的下降对地面大风预报存在2个体扫的时间提前量。5)东风波系统以动能转换的方式为本次对流天气过程中的中尺度系统发展提供动能补给。6)加强500 h Pa以上中高层东向系统的监测和雷达产品短临实时监测,可提高此类对流过程预报的时间提前量。
