RADOLAN: Radar Online Adjustment - dwd.de
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RADOLAN: Radar Online Adjustment Radar based quantitative precipitation estimation products Purpose Temporally and spatially highest resolution of the distribution of precipitation covering the complete hydrological catchment area of Germany as input for flood risk management applications of the German water management authorities and other hydrometeorological applications in real-time resp. for climatological applications. Input 1) Quantitative radar data by the 2) Rain gauge data by the radar network of DWD in time- common rain gauge network of intervals of five minutes DWD and the federal states of Germany in time-intervals of one minute Adjustment method – operationally every hour since June 1st, 2005 (Germany) resp. May 27th, 2009 (Central Europe) - correction of orographic attenuation effects and application of a variable Z-R-relationship, based on precipitation type - compositing of 17 single radar sites in Germany and additional radar sites of the neighbour countries (Denmark, Poland, Czech Republic, Austria, Switzerland, France, Belgium and the Netherlands) - summation up to one- for Germany and Central Europe and only for Germany to two-, three-, six-, twelve-, 24-hour, 48-hour and 72-hour precipitation amounts - time-dependent statistical clutter suppression with interpolation, smoothing and pre-adjustment with rain gauge precipitation parameters - calculation of two (for Central Europe) resp. three (for Germany) different mathematical gauge-radar-comparisons with interpolation - adjustment with the best combination of the two resp. three methods by calculating the adjustment quality with control stations Example: local extreme precipitation event in Braunsbach on May 29th, 2016 at 18 UTC rain gauge precipitation map Maximum values over 70 mm/h for this event are calculated by the operational radar adjustment procedure. The next rain gauge station measures only 41,5 + = mm/h, whereas the uncorrected radar data with maximum values over 100 mm/h are overestimating the precipitation amount of this event. adjusted radar precipitation map uncorrected radar precipitation map Results adjusted quantitative radar composite with hourly precipitation amounts in 1/10 mm and a spatial resolution of 1 km 2 for ←Germany, which is available within 30 minutes, and for Central Europe → with the complete hydrological catchment area of Germany, which is available within 40 minutes © DWD-Department Hydrometeorology 11/2017 – www.dwd.de/RADOLAN Dipl.-Met. Elmar Weigl, Deutscher Wetterdienst, Frankfurter Straße 135, D-63067 Offenbach/Main, [email protected] or [email protected]
Transcript of RADOLAN: Radar Online Adjustment - dwd.de
RADOLAN: Radar Online Adjustment Radar based quantitative precipitation estimation products
Purpose Temporally and spatially highest resolution of the distribution of precipitation covering the complete hydrological catchment area of Germany as input for flood risk management applications of the German water management authorities and other hydrometeorological applications in real-time resp. for climatological applications.
Input 1) Quantitative radar data by the 2) Rain gauge data by the radar network of DWD in time common rain gauge network of intervals of five minutes DWD and the federal states of
Germany in time-intervals of one minute
Adjustment method – operationally every hour since June 1st, 2005 (Germany) resp. May 27th, 2009 (Central Europe)
- correction of orographic attenuation effects and application of a variable Z-R-relationship, based on precipitation type - compositing of 17 single radar sites in Germany and additional radar sites of the neighbour countries (Denmark, Poland, Czech
Republic, Austria, Switzerland, France, Belgium and the Netherlands) - summation up to one- for Germany and Central Europe and only for Germany to two-, three-, six-, twelve-, 24-hour, 48-hour and
72-hour precipitation amounts - time-dependent statistical clutter suppression with interpolation, smoothing and pre-adjustment with rain gauge precipitation
parameters - calculation of two (for Central Europe) resp. three (for Germany) different mathematical gauge-radar-comparisons with interpolation - adjustment with the best combination of the two resp. three methods by calculating the adjustment quality with control stations
Example: local extreme precipitation event in Braunsbach on May 29th, 2016 at 18 UTC
rain gauge precipitation map
Maximum values over 70 mm/h for this event are calculated by the operational radar adjustment procedure. The next rain gauge station measures only 41,5
+ = mm/h, whereas the uncorrected radar data with maximum values over 100 mm/h are overestimating the precipitation amount of this event.
adjusted radar precipitation map
uncorrected radar precipitation map
Results adjusted quantitative radar composite with hourly precipitation amounts in 1/10 mm and a spatial resolution of 1 km2 for
←Germany , which is available within 30 minutes, and for
Central Europe → with the complete hydrological catchment area of Germany, which is available within 40 minutes
© DWD-Department Hydrometeorology 11/2017 – www.dwd.de/RADOLAN Dipl.-Met. Elmar Weigl, Deutscher Wetterdienst, Frankfurter Straße 135,
D-63067 Offenbach/Main, [email protected] or [email protected]
