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

点击翻译按钮获取中文摘要

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.