Towards a multi-year urban precipitation climatology at 100 m scale using X-band radar observations

Abstract

<p>An operational, single-polarized X-band weather radar provides measurements in Hamburg’s city center for almost eight years. This weather radar operates at an elevation angle (~3.5°) with a high temporal (30 s), range (60 m), and sampling (1°) resolution resulting<span> in a</span> high information density within <span>the</span> 20 km <span>scan radius</span>. <span>Studies on short time periods (several months) proofs the performance of this low-cost local area weather radar. </span><span>For example, a</span><span> case study on a tornado in a rain event demonstrates its refined resolution </span><span>compared to</span><span> the German nationwide C-band radars. </span><span>Now, we aim for a eight-year precipitation climatology with 100 m resolution. This data set will enable reliable studies on urban extreme precipitation. This presentation will describe h</span><span>ow we </span><span>can</span><span> infer a precipitation estimate based on multi-</span><span>year</span><span> weather radar observations in the urban area of Hamburg.</span></p><p>The single-polarization and <span>small</span> <span>wavelength</span> <span>comes along with</span> high resolution <span>but at the same time</span> high uncertainties. We address several sources of errors affecting th<span>e</span> radar-based <span>precipitation</span> estimate, like the radar calibration, alignment, attenuation, noise, non-meteorologial echoes, <span>and </span><span><em>Z</em></span><span>-</span><span><em>R</em></span><span> relation. The deployment of additional vertically pointing micro rain radars yields drop size distributions at relevant heights reducing errors effectively concerning the radar calibration and required statistical relations (</span><span><em>k</em></span><span>-</span><span><em>Z</em></span><span> and </span><span><em>Z</em></span><span>-</span><span><em>R</em></span><span> relation). We outline the performance of the correction methods for long time periods and discuss open issues and limitations.</span></p><p><span>With this high-quality and -resolution weather radar product, refined studies on the spatial and temporal scale of </span><span>urban </span><span>precipitation will be possible. </span><span>This data set will be used for</span><span> further hydrological research in an urban area </span><span>within the project <em>Sustainable Adaption Scenarios for Urban Areas – Water from Four Sides</em> of the</span><span> Cluster of Excellence <em>Climate Climatic Change, and Society</em> (CliCCS).</span></p>

Morphology and growth of convective cold pools observed by a dense station network in Germany

“…The APOLLO and WXT measurement data sets of FESST@HH 2020 and FESSTVaL 2021 are available at https://doi.org/10.25592/UHHFDM.10172 (Kirsch et al, 2021b) and https://doi.org/10.25592/UHHFDM .10179 (Kirsch et al, 2022b), respectively. The corresponding data of the X-band rain radar are available at https://doi.org/10.26050/WDCC/LAWR_UHH_HHG (Burgemeister et al, 2022a) and https://doi.org/10.25592 /UHHFDM.10090 (Burgemeister et al, 2022b). The code of the analyses performed is available at https://doi.org/10 .5281/ZENODO.8161036.…”

“…The rainfall rate estimate is obtained by applying several error corrections to the raw reflectivity signal, including correction for attenuation and noise, removal of nonmeteorological echoes, and calibration against micro rain radar measurements at MOL–RAO. The availability of quality‐controlled data throughout the measurement period is 98.2% (Burgemeister et al, 2022b). Section 5 also presents analyses based on X‐band radar measurements performed in Hamburg in 2020 (Burgemeister et al, 2022a).…”

“…The availability of quality‐controlled data throughout the measurement period is 98.2% (Burgemeister et al, 2022b). Section 5 also presents analyses based on X‐band radar measurements performed in Hamburg in 2020 (Burgemeister et al, 2022a).…”