Rain observations with a vertically looking Micro Rain Radar (MRR)

Measurements of rain were obtained with a vertically pointing micro radar (MRR) with 1 min time resolution and 50(100) m height resolution at the German Baltic coast on the Zingst peninsula (54.43°N, 12.67°E). The comparison with a conventional rain gauge (30 min integration time) for a five months summer period show a correlation coefficient of [[rho][eta][omicron]] = 0.87 for the rainrate and agreement within 5% for the total rainfall integrated over the whole period. Single measurements with 30 min integration time showed deviations up to a factor of 2 between MRR and rain gauge. Classification of the measurements into rainrate intervals shows that rainrates around 0.2 mm h–1 provide the highest contribution per rainrate interval to the total rainfall. Typical distributions of number-concentration, liquid-water- concentration and rainrate versus drop size, retrieved with the MRR, are presented. Simultaneous estimates of rainrate and reflectivity factor with data of a C-band (frequency 6 GHz) weather radar suggest that the MRR may be used to support quantitative rainrate estimates with weather radars. The weather radar used for comparison is operated by the German Weather Service and is situated 51 km from the MRR.