Statistics on clouds and their relation to thermodynamic conditions at Ny-Ålesund using ground-based sensor synergy.

The French–German Arctic Research Base AWIPEV at Ny-Ålesund, Svalbard, is an unique station for monitoring cloud related processes in the Arctic. For the first time, data from a set of ground-based instruments at AWIPEV observatory are analyzed to characterize the vertical structure of clouds. For this study, a 14-month dataset from Cloudnet combining observations from a ceilometer, a 94GHz cloud radar and a microwave radiometer, is used. The total cloud occurrence of 81%, with 44.8% of multi-layer and 36% of single-layer clouds was found. Among single-layer clouds the occurrence of liquid, ice and mixed-phase clouds was 6.4%, 9% and 20.6%, respectively. It was found, that more than 90% of single-layer liquid and mixed-phase clouds have LWP values lower than 100 and 200gm², respectively. Mean values of IWP for ice and mixed-phase clouds were found to be 273 and 164gm², respectively. The different types of single-layer clouds are also related to in-cloud temperature and relative humidity under which they occur. Statistics based on observations are compared to the ICON model output. Distinct differences in liquid phase occurrence in observations and the model at different environmental temperatures leading to higher occurrence of pure ice clouds and lower occurrence of mixed-phase clouds in the model at temperatures between −20° and −5°C become evident. The analyzed dataset is useful for satellite validation and model evaluation. [ABSTRACT FROM AUTHOR]