The HD(CP)2 Observational Prototype Experiment (HOPE) is a fundamental part of the full project.
The HD(CP)2 project aims at a breakthrough in simulating clouds and precipitation by identifying how different representations of processes on their relevant spatio-temporal scales contribute to the overall skill of the simulations. The Project O4 “HD(CP)2 Prototype Experiment ” is designed to provide a critical model evaluation at the scale of the model simulations and further to provide information on sub grid variability and microphysical properties that are subject to parameterizations even at high-resolution simulations. Cross cutting activities with the partner projects within the Observation Module will provide optimal integration of the O4 data into the overall model evaluation activities.
The O4 focuses on the onset of clouds (activation) and precipitation (auto conversion) in the convective atmospheric boundary layer. By capturing the 3D cloud distribution the measurement can support the investigation of cloud-overlap and 3D radiative effects. In the absence of boundary layer clouds, the O4 remote sensing instrument system is ideally suited to retrieve aerosol and cirrus cloud properties. O4 ideally complements the larger spatio-temporal Full-Domain (O2) and Supersites (O1) activities in the Observations Module. Tools for small scale model evaluation developed in the Integration project (O3) will be applied to the observed atmospheric fields. Surface energy flux closure studies will serve as integration tool of all available O4 data and will provide the link between HD cloud and surface flux variability.