The Elbe Case Study simulated with REMO with modified cloud microphysics

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The Elbe Case Study simulated with REMO with
modified cloud microphysics
Susanne Pfeifer, Max-Planck-Institute for
Meteorology, Hamburg
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Outline

• Short introduction to the cloud microphysics in
  REMO
• Elbe case study comparison to Observations
• Consequences of changed cloud microphysics on
  model behaviour
• Conclusions

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Model simulations
1/6 horizontal resolution (approx. 18 x 18
km) 20 vertical levels

• REMO standard
• REMO ice
• initialisation 01. August 2002
• integration period August 2002
• driven by ECMWF-Analyses

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Clouds in REMO
both
Mass flux convection scheme after Tiedke with
modifications after Nordeng (CAPE closure for
penetrative convection)
REMO standard
REMO ice
Stratiform clouds budget equations for water
vapor and cloud liquid water (Sundquist).
Stratiform clouds budget equations for water
vapor, cloud liquid water and cloud ice (Lohmann
and Roeckner).
Subgrid-scale cloud formation is taken into
account
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Cloud Microphysics
Evaopration / Condensation
Evaporaion of precipitation
diagnostic
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Cloud Microphysics
Sublimation / Deposition
Evaopration / Condensation
Evaporaion of precipitation
Melting / Freezing
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Precipitation 10.8 06 13.8. 06 UTC
Observations Elbe catchment 76 mm/72h
REMO standard Elbe catchment 53 mm/72h
-gt 70
Figure taken from Rudolf Rapp, DWD 2003
Bundesanstalt für Gewässerkunde (BfG, 2002)
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Precipitation 10.8 06 13.8. 06 UTC
Observations Elbe catchment 76 mm/72h
REMO standard Elbe catchment 53 mm/72h
-gt 70
REMO ice Elbe catchment 66 mm/72h
-gt 87
Neu Darchau
Figure taken from Rudolf Rapp, DWD 2003
Bundesanstalt für Gewässerkunde (BfG, 2002)
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Temporal evolution

• Identical temporal evolution
• Higher maxima for REMO ice

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hourly precipitation
Figure taken from Rudolf Rapp, DWD 2003
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hourly precipitation
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hourly precipitation
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Atmospheric Temperature Dresden
REMO standard
REMO ice
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Clouds Dresden
REMO standard
REMO ice
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Clouds Dresden
REMO standard
REMO ice
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Mean profiles 8 days Elbe area
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Precipitation intensities

• Hourly precipitation
• elbe catchment area
• 2002-08-09 to 2002-08-17

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Precipitation intensities
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Conclusions

• Implemented Changes in cloud microphysics result
  in higher total amount of precipitation as well
  as stronger extreme precipitation events (For the
  Elbe Flooding 2002)
• Changes in the vertical distribution of cloud
  water have to be assessed ( -gtdiscussion of
  workshop cases this afternoon )

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dynamics lt-gt microphysics
Remo Standard climate mode
Remo Standard climate mode
Remo Standard forecast mode
Remo ice