The IPT has been enhanced and provides continuous estimates of vertical profiles of temperature, humidity, cloud water content, and effective radius. A separate treatment of drizzle water content and effective radius is under development. The retrieval scheme integrates meaurements, i.e. brightness temperatures of a multichannel microwave radiometer and cloud radar reflectivities, and prior information, i.e. climatological profiles of radiosondes or forecast data from a numerical weather prediction model, together with their uncertainties in a physically consistent way. Thus, we provide a best-estimate product for the vertical column with maximum information content. Note that the retrieval framework directly provides uncertainty estimates of the retrieved parameters, which is essential for the assessment and the exploitation of the retrieval results.
Here, we will demonstrate the application of the IPT by means of some case studies and also compare the retrieval results to other retrieval methods and observational data sets. At the Jülich Observatory for Cloud Evolution (JOYCE), the cloud optical depth and effective radius from sunphotometer observations in cloud mode (Chiu et al., 2012) as well as cloud properties from satellite observations (SEVIRI) are incorporated in the analysis. In-situ observations of a persistent stratocumulus cloud case were performed in Melpitz close to Leipzig during HOPE (HD(CP)2 Observational Prototype Experiment)-Melpitz by the helicopter-borne Airborne Cloud Turbulence Observation System ACTOS. By means of these data sets, a comprehensive assessment of the IPT results is performed. Within 2014, the IPT will be operationally implemented at the ground-based cloud observatories in Jülich, Lindenberg, and Cabauw.