Assimilation and Simulation of radar reflectivities using mesoscale NWP models

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De-aliasing of Doppler radar winds using a torus
mapping
G. Haase and T. Landelius
Swedish Meteorological and Hydrological Institute
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Doppler wind measurements
Quality control (e.g. de-aliasing)
Assimilation into NWP models (e.g. VAD profiles,
superobservations )
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Aliasing problem
Doppler dilemma
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De-aliasing algorithm
Linear wind model
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De-aliasing algorithm
Linear wind model
Map the measurements onto the surface of a torus
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Case study
Hemse (Sweden) 2 July 2003, 1047 UTC
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Validation
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Application 1 Wind profiles (VVP)
Vantaa (Finland) 4 December 1999, 1200 UTC
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Application 2 Superobservations
Karlskrona (Sweden) 3 December 1999, 1830 UTC
D. B. Michelson
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Summary

• accurate robust post-processing algorithm
• (elimination of multiple folding)
• no additional wind information needed
• (independent data source)
• improve quality of wind profiles and
  superobservations for data assimilation
• potential for further reduction of computational
  costs (real-time applications)