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Simulated radar measurements in NWP-model validation

Carl ForteliusFinnish Meteorological Institute

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Contents:

1. What are simulated radar measurements

2. Why are they needed

3. What do they tell

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Special thanks to:

Günther Haase and DWD for the RSM code

Harri Hohti for radar data

Sami Niemelä for Hirlam output

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3D NWP model output:T, q, hydrometeors

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Volume backscatteringcoefficient (Mie)

3D NWP model output:T, q, hydrometeors

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Radar ray propagation,extinction

Volume backscatteringcoefficient (Mie)

3D NWP model output:T, q, hydrometeors

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Radar ray propagation,extinction

Volume backscatteringcoefficient (Mie)

Simulated measurements:PPI, RHI,statistics,...

3D NWP model output:T, q, hydrometeors

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Example: Comparing two parameterizations of convectionand moist physics in HIRLAM

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Example: Comparing two parameterizations of convectionand moist physics in HIRLAM

Model: HIRLAM 5.0.0Resolution: 40 levels, 5.5 kmExperiments (Sami Niemelä, Univ. Helsinki):

HHS: Reference version HHK: ''STRACO'' replaced by ''RKKF''

Boundaries & initial state: FMI operational analyses (31 levels, 22 km)

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Example: Comparing two parameterizations of convectionand moist physics in HIRLAM

Model: HIRLAM 5.0.0Resolution: 40 levels, 5.5 kmExperiments (Sami Niemelä, Univ. Helsinki):

HHS: Reference version HHK: ''STRACO'' replaced by ''RKKF''

Boundaries & initial state: FMI operational analyses (31 levels, 22 km)

Radars: Gematronik 5.6 GHz, Sigmet signal processingVantaa, Ikaalinen, Anjalankoski

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Analysis 25 May 2001 12 UTC

Model domain and composite area

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Conclusions

NWP-models produce realistic(?) reflectivity distributions

RSM only (?) way to verify vertically distributed hydrometeors

RSM brings out differences between alternative model formulationswhen traditional methods fail

RSM is computationally demanding