Speaker
Description
Dual-polarisation X-band radars have become popular tools in the operational and research sectors to address a broad range of scientific goals: examining cloud microphysics, monitoring up-close and rapidly developing storms, quantitative precipitation estimation (QPE), among others. These weather radars can fill gaps in existing operational radar networks or provide precipitation estimates with higher temporal and spatial resolution in areas of particular interest, e.g., urban environments.
This study thoroughly investigates rain-rate retrievals derived from polarimetric X-band measurements. In particular, events related to severe heavy rain that occurred in the Rhenish mining region (western Germany) are examined. The DWD operational C-band radar network is used to evaluate the performance of the X-band radars for QPE, but also to assess the improvements when using the latter as gap fillers. The advantages and main challenges of using X-band radars for QPE are also presented. For instance:
- Attenuation resulting from rain is significant at shorter wavelengths. It was observed that at the X-band wavelength, the specific attenuation $(A_H)$ and specific differential attenuation $(A_{DP})$ are up to three times larger than those at C-bands. Even more, heavy attenuation can lead to the total extinction of the signal in the presence of thunderstorms.
- It is required to implement robust techniques for quality control, calibration monitoring, rainfall estimation and compositing of precipitation products based on polarimetric data collected by C-and X-band radars to generate reliable QPE products.
- There are clear benefits of using rain estimators based on $A_H$ or the specific differential phase $(K_{DP})$ over traditional $R(Z_H)$ or $R(Z_H,Z_{DR})$ estimators as the former show a better performance in the presence of heavy rain when compared with rain gauge measurements, due to the independence of $A_H$ and $K_{DP}$ on radar power calibrations, less sensitivity to DSD variations, and being relatively immune to attenuation and beam blockage. However, methodologies especially devised to improve $R(Z_H)$ and hybrid $R(Z_H,A_H)$, $R(Z_H,K_{DP})$ estimators and overcome the issues related to power-based measurements are presented.
| Presenting Author | Daniel Sanchez-Rivas |
|---|---|
| Email Address of Presenting Author | dsanche1@uni-bonn.de |
| Affiliation of Presenting Author | University of Bonn |
| Address of Presenting Author | Auf dem Hügel 20, 53121, Bonn, DE |
| Session | Precipitation and Hydrological Models: Extreme precipitation events |
| Preferred Contribution Type | Oral Presentation |
