EROSION Report D1.4 Data on rain drop size distribution at selected sites

The rain drop size distribution data collected in the EROSION project are important for further insight to the environmental conditions causing the leading edge erosion at turbine blades. The data set is unique. Firstly, data are collected a sites highly relevant for offshore turbines. Secondly, contrasting rain and wind climate conditions exist at the various stations and enable in-depth analysis of similarities and differences. Thirdly, one-year long observations enable seasonal characterization of the rain-wind climate. The disdrometer stations cover sites in eastern Denmark (Risø, Roskilde), central Denmark (Voulund, Jutland) and coastal stations at the west coast (Hvide Sande and Thyborøn, Jutland) and offshore in the Baltic Sea (Rødsand) and the North Sea (Horns Rev 3). In addition, data at two heights 5m and 123m are collected at Risø, to characterize possible differences in rain-wind climate with height. Wind turbines operate around 100 m so the rain-wind climate at this height is of special importance. Two other perspectives will be covered from the EROSION disdrometer network. One perspective is to make it possible to do analysis between the DMI dual-pol radar data. This analysis will be important for improving and verifying the accuracy in the now casting of rain events. The other perspective is to identify the rain drop sizes most relevant for rain erosion testing in laboratories, to mimic particular environmental conditions relevant for leading edge erosion. The Parsivel2 disdrometer is the state of the art instrument. Comparison to a novel radar-based instrument (WS100) was performed. Unfortunately, the data quality from WS100 is not of sufficient quality for the application of leading edge erosion. The data are stored in MySQL database with documentation of the parameters.