4-dimensional remote sensing based on the Convective and Orographically-induced Precipitation Study (COPS) for studying convective initiation in complex terrain

在“世界天气研究计划”的一个研究及发展项目“对流及地形诱导降水研究”（COPS）中，我们收集了38个密集观测日的对流降水事件整个演变过程的高质量、高分辨率四维数据，这在以前是无法实现的。总共有13个平台使用了17种不同类型的激光雷达系统——地面和机载，扫描和垂直指向。在这个项目中，我们建议利用这些数据集，目的是分析在特定地点和时间导致对流起始（CI）的大气过程。CI的位置和时间误差是降水定量预报中最关键的问题。这项研究的关键仪器特别是那些提供大气热力学状态高分辨率数据的仪器。因此，本项目除了考虑探空、气象站和现场飞机仪器的标准数据外，还应特别重视激光雷达、云雷达和微波辐射计在不同平台上的数据开发。此外，雷达的晴空回波，特别是cop期间使用的两个多普勒轮上回波，应使用用于识别与CI相关的动力学特征，如收敛线。地面遥感仪器分别安装在五个超级站点。这样就可以从相对湿度、虚拟位势温度及其梯度、浮力、CAPE和CIN等仪器组合中获得协同数据产品，这被认为对推进CI过程研究非常有益。通过将这些数据与空中测量的水汽和风廓线相结合，可以探索大气热力学状态的四维演变。然后，这些过程研究的结果将与相应的理论进行比较，并用于验证新一代中尺度数值天气预报模式。这里特别有趣的是湍流和对流的参数化的验证。

Within the Convective and Orographically-induced Precipitation Study (COPS), a Research and Development Project of the World Weather Research Programme, a previously unachieved set of high-quality high-resolution 4D data of the entire evolution of convective precipitation events has been collected on 38 intensive observation days. In total 13 platforms with 17 different types of lidar systems alone have been operated – groundbased and airborne, scanning and vertical pointing. In this project, we propose to exploit this data set with the aim to analyse atmospheric processes which lead to convection initiation (CI) at a certain location and time. Errors in location and time of CI are within the most critical issues in the effort to forecast precipitation quantitatively. Key instruments for this study are especially those which provided high-resolution data of the thermodynamic state of the atmosphere. Thus, - besides considering also standard data of radiosondes, weather stations and in-situ aircraft instruments - this project shall put special emphasis on data exploitation of lidars, cloud radars, and microwave radiometers on different platforms. Furthermore, clear-air echoes of radars, especially of the two Doppler-on-Wheels employed during COPS, shall be used to identify dynamical features related to CI like convergence lines. The ground-based remote sensing instruments were collocated at five supersites. This allows deriving synergetic data products from the combination of instruments like relative humidity, virtual potential temperature and its gradient, buoyancy, CAPE and CIN, which is considered highly beneficial to advance CI process studies. By combining these data with airborne measurements of water vapor and wind profiles, the 4-dimensional evolution of the thermodynamic state of the atmosphere can be explored. The results of these process studies shall then be compared with corresponding theories and be used to validate the new generation of mesoscale numerical weather-prediction (NWP) models. Of special interest is here the validation of parameterizations of turbulence and convection.