MICROphysicS of COnvective PrEcipitation (MICROSCOPE).

该项目将通过解决对流云中降水的微物理问题来改进对强对流降雨的预报。作为对流降水实验(COPE)的一部分，对微物理的研究第一次被嵌入到一个包括对流云更大尺度动力学的项目中。COPE将把这项微物理研究与英国强对流天气事件的系统尺度动力学联系起来。COPE还将提供天气系统模拟方案，这将使人们更好地了解天气系统或集水区尺度的降雨预报。天气预报模型目前的分辨率为1.5公里，这有助于改进对流地点和时间的预报。然而，正如博斯卡斯尔事件(Golding等人，2005年)所强调的那样，定量降水预报仍然很差。这在一定程度上是由于缺乏关于对流云中冰粒的成核、暖雨过程以及次生冰粒的产生速度和随后降水粒子的生长的知识。然而，高的局部积累是降水强度(降水的微物理)和持续时间(沿汇聚线的细胞的组织和相互作用)的结果。后一个问题和更广泛的问题将在COPE的其他部分解决。显微镜有两个关键部分。第一个问题涉及一个基本问题：冰核(IN)是如何在云中形成冰粒的，特别是在高温下？第二个问题是降水：降水粒子是如何形成的？产生和发展的速度是多少？显微镜将通过以下方式解决解释积云中初级冰粒产生的挑战。*我们将使用FAAM 146飞机在地面和边界层测量气溶胶粒子的性质，特别是土壤和生物材料。*将测量液滴尺寸分布的演变，可能存在过冷雨滴，以及第一批冰粒的形成，飞机已经配备了新的仪器，可以明确地探测和表征小冰粒(SID，2DS，CAS-DPOL)。*双极化，多普勒雷达将提供第一次降水回波的位置和时间、空气运动和粒子类型的测量。为了解释降水的产生和发展，过程模式和NWP模式的结果将与夹带过程、暖雨过程的发展、通过扩散增长形成降水粒子的冰粒增长、雨滴冻结成碎屑粒子、二次生产过程的繁殖和结圈的观测结果进行比较。比较将通过在不断增加的高度进行多次穿透来实现，测量粒子在空间和时间上的分布以及云的热力学和动力学，并通过从双极化雷达获得关于粒子和反射率回波的增加速率的信息。将由英国气象局领导的显微镜的最后一步是将新的信息纳入数值预报模型，并与项目期间收集的数据进行测试。

This project will improve predictions of severe convective rainfall by addressing the problem of the microphysics of precipitation in convective clouds. For the first time, study of the microphysics is embedded in a project that includes the larger-scale dynamics of convective clouds, as part of the COnvective Precipitation Experiment (COPE). COPE will connect this microphysical study with the system-scale dynamics of severe convective UK weather events. COPE will also provide a programme of weather-system modelling, which will bring the microphysical understanding through to the improved prediction of rainfall at the weather-system, or catchment scale.Weather forecast models are now run at resolutions of 1.5 km, which has helped to improve the prediction of the location and timing of convection. However, quantitative precipitation forecasts are still often poor as highlighted in the Boscastle event (Golding et al., 2005). This is due in part to the lack of knowledge about the nucleation of ice particles in convective clouds, the warm rain process, and the rates of production of secondary ice particles and the subsequent growth of precipitation particles. However, high local accumulations were the result of both intensity (microphysics of precipitation) and duration (organisation of and interaction between cells along the convergence line) of precipitation. The latter issue and wider-scale problem will be addressed in other parts of COPE.There are two key parts to MICROSCOPE. The first concerns a fundamental problem: how do ice particles form in clouds as a result of ice nuclei (IN), particularly at high temperatures? The second concerns precipitation: how do precipitation particles form and what are the rates of production and development? MICROSCOPE will address the challenge of explaining the production of primary ice particles in cumulus clouds, in the following ways.* We will make measurements of the properties of the aerosol particles, particularly soils and biological material, on the ground and in the boundary-layer with the FAAM 146 aircraft.* Measurements will be made of the evolution of the droplet size distribution, the possible presence of supercooled raindrops and the formation of the first ice particles with carefully-guided penetrations of the aircraft that has been equipped with new instruments that can detect and characterise small ice particles unambiguously (SID, 2DS, CAS-DPOL).* The dual-polarisation, Doppler radars will provide measurements of the location and time of the first precipitation echoes, the air motions and the types of particles.In order to explain the production and development of precipitation, process model and NWP model results will be compared to observations of the entrainment process, the development of the warm rain process, the growth of ice particles into precipitation particles by diffusional growth, the freezing of raindrops into graupel particles, multiplication by secondary production processes, and riming. The comparisons will be achieved by making multiple penetrations at increasing altitudes measuring the particle size distributions in space and time as well as the thermodynamics and dynamics of the cloud, and by obtaining information about the particles and the rate of increase of the reflectivity echo from the dual-polarisation radar.The final step of MICROSCOPE, that will be led by the Met Office, is to incorporate the new information into NWP models and to test against the data gathered during the project.