Reanalysis of multi-year high-resolution X-band weather radar observations in Hamburg

Abstract

Abstract. Operational rain gauge networks provide reliable local precipitation measurements, but are unable to represent rainfall variability for large domains at small temporal scales. In the urban area of Hamburg, precipitation measurements of a single-polarized X-band weather radar operating at a high temporal (30 s), range (60 m), and azimuthal sampling (1°) resolution are available for more than eight years. These measurements refine observations of the German nationwide C-band radars within the 20 km scan radius. Studies on short time periods (several months) prove the performance of this low-cost local area weather radar. A case study on a tornado in a rain event demonstrates its refined resolution compared to the German nationwide C-band radars. The deployment of additional vertically pointing micro rain radars yields drop size distributions at relevant heights, which reduces errors effectively concerning the radar calibration and required statistical relations (k-Z and Z-R relation), and monitors the radar data quality. This paper describes an open-access data set covering reanalysed radar reflectivities and rainfall estimates measured by an X-band radar at high spatio-temporal resolution in the urban environment of Hamburg between 2013 and 2021. Additionally, this paper outlines the performance of this X-band radar for long time periods, and discuss open issues and limitations of the data set. The provided radar reflectivities facilitate studies on attenuation correction and the derivation of further weather radar products, like an improved rainfall rate. The rainfall rates will be used for studies on the spatial and temporal scale of precipitation and hydrological research, e.g. input data for high-resolution modelling, in an urban area.