Theoretical and Applied Climatology

, Volume 40, Issue 4, pp 209–226 | Cite as

Observations of dynamical and microphysical aspects related to hail formation with the polarimetric Doppler radar Oberpfaffenhofen

  • P. Meischner


For improving hail suppression strategies much more detailed knowledge on the individual hail formation process within the thermodynamical as well as the dynamical framework of hail producing cloud systems is needed. One possibility to obtain such knowledge on microphysical and dynamical processes simultaneously is with polarimetric Doppler radar measurements. The advanced polarimetric Doppler radar Oberpfaffenhofen, in operation since summer 1987, is described. Its unique capabilities, such as the real time estimation and display of the three Doppler moments reflectivity, Doppler velocity and spectral width as well as polarimetric parameters, such as depolarization ratios and the differential reflectivity are presented. Furthermore, from polarimetric measurements a hail signal is implemented which can be displayed in real time, too.

The microphysical as well as dynamical structure of a squall line has been observed and a conceptual model of the hail formation process within this system is presented, thus illustrating the detailed insights into cloud processes possible with this new radar system.


Radar Cloud System Squall Line Suppression Strategy Depolarization Ratio 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Ein neu entwickeltes Wolkenradar, ein polarimetrisches Dopplerradar, ist seit Anfang 1987 in Oberpfaffenhofen in Betrieb. Ein Schwerpunkt der Anwendungen liegt bei der Untersuchung hochreichender Konvektion mit Hagelbildung. Die in Echtzeit berechneten und dargestellten Dopplermomente Reflektivität, Dopplergeschwindigkeit und Spektralbreite der Dopplergeschwindigkeit ermöglichen die Verfolgung der dynamischen und turbulenten Vorgänge. Gleichzeitig können polarimetrische Parameter, wie z. B. Depolarisationsverhältnisse und die differentielle Reflektivität, berechnet und dargestellt werden, die Aufschluß über die im Auflösungsvolumen vorhandenen Hydrometeorarten geben. Insbesondere wurde ein aus polarimetrischen Messungen berechnetes Hagelsignal implementiert. Die Niederschlags- und Hagelentwicklung wurde in einer Squall Line mit dem Radar verfolgt, so daß der Hagelentstehungsprozeß konzeptionell beschrieben werden kann. Eine wesentliche Rolle bei der Hagelentwicklung spielten offenbar isoliert vor der Squall Line entstandene Kumuluswolken, die im mittleren Niveau auf der Vorderseite des Systems eingemischt werden.


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Copyright information

© Springer-Verlag 1989

Authors and Affiliations

  • P. Meischner
    • 1
  1. 1.Institut für Physik der AtmosphäreDeutsche Forschungsanstalt für Luft- und Raumfahrt e. V.Oberpfaffenhofen, WesslingFederal Republic of Germany

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