Analysis of CLIWA-NET intensive operation period data as part of the monitoring activities at the German Meteorological Service site Lindenberg

Abstract

The improvement of the parameterization of cloud processes with a focus on cloud liquid water and vertical structures of clouds was defined as an important aim of the EU-project CLIWA-NET (Cloud Liquid Water Network). In compliance with its main goals, a ground-based network was established to obtain cloud properties during two intensive operation periods. The Meteorological Observatory Lindenberg was an integrated part of this network performing microwave profiler retrievals and complementary measurements. In order to provide accurate observations, methods are developed which enable an automatic quality control of microwave radiometer data. The algorithm includes other continuously available measurements from radiosondes and GPS. The access to accurate observations and a routine evaluation of data quality is required for further applications. Assessment of retrieval accuracy and investigations about the diurnal cycle obtained at Lindenberg are presented to exemplify the usefulness of reference sites as an essential component of any observational program. With respect to cloud liquid water estimates, it is shown that the integrated values are in good agreement with calculations derived from radiosondes. The low-resolution liquid water profiles show deviations in cloud base height, especially for fractional cloudiness.