Intercomparison of various cloud radar-based retrieved water cloud properties

For a better understanding of the complex processes from increased anthropogenic aerosol production to changes in cloud albedo the relevant aerosol, cloud and radiation features are required. The detection of these properties can be achieved through the synergy of ground-based remote sensing measurements with high spatial and temporal resolution. This work introduces a retrieval technique of microphysical and optical cloud properties on the basis of radar, microwave radiometer and ceilometer observations in combination with a vertical model. The greatest difficulty within this strategy is the quantification of the impact of cloud properties on the surface radiation budget, which is dominated by uncertainties in the model assumptions and the errors in the surface observations. In previous studies the optical retrievals are proved by a radiative closure experiment, which compares radiation observations with simulations based on the retrieved optical properties. A further step towards the quantification of the cloud albedo effect requires an improvement of various cloud property retrieval techniques in order to elucidate the physical processes behind. This paper presents the application of the introduced retrieval technique on water cloud cases, whereas the results and the sensitivity will be analyzed in comparison to results of similar ground-based retrieval techniques. The intercomparison of different cloud retrievals will demonstrate the accuracy of various retrieval techniques, which could lead to an improvement of the quantification of the complex processes involved in the first indirect aerosol effect.