长江口浅对流（垂直）结构特征与增强关键机制的研究

The shallow convection has non-neglect impact on the atmospheric condition that favors deep convection by the modification of thermodynamic vertical structure within atmospheric boundary layer and the free-atmosphere right above it, via the vertical transportation of heat, momentum and water vapor. If local generated shallow convection transfer to deep convection which could induce disastrous weather such as short-term heavy rainfall, gale and thunderstorm in the urban area, it will bring sever threaten to both cities’ safely operations and peoples’ lives and properties..However, due to the suddenness, rapidly development and small size in spatial coverage, it is still very hard for conventional and operational weather monitoring system and numerical weather prediction model to effectively monitor and accurately predict the local deep convection. It may remain one of the difficulties in operational weather prediction in foreseeable future. Studies show that, fully understand the key mechanism of the transportation from shallow convection to deep convection could be a vital path to solve the problem..Therefore, the proposed program would focus on the (vertical) structure and the mechanism for the enhancement of shallow convection generated at the estuary of Yangtze River. In order to provide the first-hand of observation and analysis of the characteristics of the evolution for the shallow convection, and provide the reference for the development of localized parameterization scheme for numerical weather predict model. Thus to make positive contributions to the improvement of meteorological service ability and weather prediction ability.

浅对流能够通过热、动量和水汽的垂直输送改变大气边界层和边界层顶部自由大气的热动力垂直结构，对形成适宜深对流过程产生的湿热条件有着不可忽视的作用。而在人口密集的城市区域，当局地触发的浅对流增强成为局地强对流时，能够引发短时强降水、大风、雷暴等灾害性天气，对城市的安全运行和居民的生命财产安全造成巨大威胁。.但是由于此类局地对流过程的突发性强、发展迅速、空间尺度小，传统的业务化气象观测手段和数值天气预报模式难以形成对其有效的监测和准确预报，在可见的未来仍是业务天气预报的难点问题之一。前人研究表明，掌握浅对流向深对流转化的关键机制，是应对这一问题的关键途径。.因此，本项目以长江口浅对流（垂直）结构和增强机制为着眼点开展研究，在为掌握长江口浅对流演变特征的基本事实提供第一手观测与分析的同时，也为数值天气预报模式发展本地化的物理过程参数化方案提供核心参考，进而为提升气象服务能力和预报能力做出积极贡献。

掌握长江口浅对流（垂直）结构和由浅向深转化的关键机制，对于应对浅对流转化为强对流后对城市安全运行和居民生命财产安全造成的巨大威胁有重要意义。.因此，本项目以长江口浅对流（垂直）结构和增强机制为着眼点开展研究，.（1）开展了服务长江口浅对流个例识别的地基遥感观测的质量评估分析。深入分析毫米波云雷达、微波辐射计等具有高时空分辨率探测能力的地基遥感观测手段的质量评估，为综合运用此类观测仪器开展长江口浅对流识别与分析打下坚实基础。.（2）研发了综合运用风云卫星云图、各气压场位势高度、风速风向、地面风场、08时探空资料、6小时地面累积降水，从各高度大尺度环流形势、地面辐合、温湿度垂直层结结构和地面降水覆盖范围等角度识别增强型浅对流识别技术。同时研发了基于热力能量指数、地面降水实况和地基云雷达遥感观测的维持型浅对流识别技术。.（3）综合运用多元遥感观测和数值模式大涡模拟，开展了大尺度天气过程背景下和副高控制下典型增强型浅对流过程的（垂直）结构演变特征和触发关键机制，凝练总结了近地层高温、高湿条件和地面扰动引起的辐合是浅对流增强的关键机制。.本项目研究成果在为掌握长江口浅对流演变特征的基本事实提供第一手观测与分析的同时，也为数值天气预报模式发展本地化的物理过程参数化方案提供核心参考，进而为提升气象服务能力和预报能力做出积极贡献。