Puskeiler et al. (2016) Hail statistics for Germany derived from single-polarization radar data

Identification

• Journal: Atmospheric Research
• Year: 2016
• Date: 2016-05-03
• Authors: Marc Puskeiler, Michael Kunz, Manuel Schmidberger
• DOI: 10.1016/j.atmosres.2016.04.014

Research Groups

• Institute of Meteorology and Climate Research (IMK), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
• German Aerospace Center, Wessling, Germany (affiliation for one author at the time of publication)

Short Summary

This study developed and validated a method to estimate hail signals from conventional single-polarization radar data (2005-2011) across Germany, revealing high spatial variability in hail days with systematic patterns influenced by climate and orography. The method's reliability was confirmed by comparing radar-derived hail days with insurance loss data, achieving a Heidke Skill Score of 0.7.

Objective

• To develop and validate a reasonable method for estimating hail signals from 3D radar reflectivity measured by conventional single-polarization radars.
• To construct a reliable hail probability map and derive comprehensive hail statistics for Germany.

Study Configuration

• Spatial Scale: Germany (country-wide), with analysis at large, regional, and local scales.
• Temporal Scale: Seven years, from 2005 to 2011.

Methodology and Data

• Models used: A method was developed to estimate hail signals from 3D radar reflectivity data. This method is not given a specific model name but is described as a technique for signal estimation.
• Data sources:
  • 3D radar reflectivity data from conventional single-polarization C-band radars.
  • Loss data from a building insurance company and an agricultural insurance company for validation.

Main Results

• The developed method for estimating hail signals from single-polarization radar data was confirmed as reliable, demonstrating a Heidke Skill Score (HSS) of 0.7 when evaluated against insurance loss data.
• Radar-derived hail days exhibit very high spatial variability across Germany, reflecting the local-scale nature of deep moist convection.
• Systematic patterns related to climatic conditions and orography are observable.
• On a large scale, the number of hail days substantially increases from north to south across Germany, likely due to higher thermal instability in the southern regions.
• At regional and local scales, several "hot spots" with elevated hail frequency were identified, often located downstream of mountainous areas.
• Other characteristics, including convective energy related to events, differences in track lengths, and seasonal cycles, were also discussed.

Contributions

• Provides a novel and reliable method to estimate hail occurrence using widely available conventional single-polarization radar data, addressing the significant lack of direct hail observations for large areas like Germany.
• Generates the first consistent and comprehensive hail statistics and a hail probability map for Germany based on radar data.
• Offers new insights into the spatial variability and systematic patterns of hail occurrence across Germany, linking them to climatic and orographic influences.
• Validates radar-derived hail days using independent insurance loss data, enhancing the credibility and practical applicability of the findings for stakeholders such as the insurance industry.

Funding

Not specified in the provided text.

Citation

@article{Puskeiler2016Hail,
  author = {Puskeiler, Marc and Kunz, Michael and Schmidberger, Manuel},
  title = {Hail statistics for Germany derived from single-polarization radar data},
  journal = {Atmospheric Research},
  year = {2016},
  doi = {10.1016/j.atmosres.2016.04.014},
  url = {https://doi.org/10.1016/j.atmosres.2016.04.014}
}