Status of working group Precipitation Processes and Live cycle Martin Hagen DLR Oberpfaffenhofen

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Status of working groupPrecipitation Processes
and Live cycleMartin HagenDLR Oberpfaffenhofen
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Precipitation observed at ground is the result of
a long chain of complex processes
Aerosols
Condensation
Nucleation
Riming
Temperature
CN
Ice density
IN
Falling
Radiation
Pressure
Aggregation
Convection
Wind field
Advection
Freezing
Melting
Convergence
Humidity
Coagulation
Water vapour
Cloud cover
Orography
Hydrology
Soil moisture
Precipitation
Evaporation
Land use
Vegetation
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Interaction with other working groups
WG Convection Initiation
WG Precipitation Processes and Lifecycle
WG Aerosol Cloud Microph.
WG Data Assimilation
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Scientific questions

• Orography can trigger the development of cells,
  however, it is open whether convection is
  suppressed in the subsiding flow in the lee of
  hills.
• The life cycle of single cells can be modulated
  by orography, but it is open whether orography
  like Vosges Mountains or Black Forest can have a
  significant influence on the formation and
  propagation of multi- or super-cells or even
  mesoscale convective systems.
• How significant is this influence if the cells
  have been already formed before they interact
  with orography?
• Can embedded convection be triggered by
  topography. Formerly stably stratified
  precipitation may be destabilized by the forced
  uplift through mountains.

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Required Instruments

• Sounding (radio sondes, drop sondes)
• Wind profilers, Sodars
• Cloud radar
• Doppler weather radar
• Polarization weather radar
• Rain gauges
• Vertical pointing rain radar
• Disdrometer
• Airborne particle observations

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Observation Strategy

• Sounding (radio sondes, drop sondes)
• Wind profilers, Sodars
• Cloud radar
• Doppler weather radar
• Polarization weather radar
• Rain gauges
• Vertical pointing rain radar
• Disdrometer
• Airborne particle observations

Mapping of the environment(hourly) Mapping of
cloud prior to precipitation development (volumes
every 5-10 minutes) Mapping of dynamics and
microphysics (volumes every 5-10
minutes) Continuous operation Storm penetration
at -10 to -20C height(frequent at graupel
initiation and electrification phase)
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Set up of instruments 3rd COPS WS April 2006
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• AMF
• Micropulse lidar, cloud radar, sondes)
• IfT lidars (aerosol and Doppler)
• LMU microwave radiometers
• Hornisgrinde (UHOH lidars, FZK doppler lidar and
  cloud radar)
• Polirad
• 2 radiosonde stations
• UNIBAS Raman lidar
• MICCY radiometer
• 5 MMRs (4 Hamburg, 1 FZK)
• Ka-band cloud radar (Hamburg )
• X-band radar (Hamburg)
• 2 sodars (FZK), 1 Freiburg, 1 Bayreuth
• MWRP from Potenza
• Wind profiler (FZK)
• S-Pol
• TARA cloud radar
• UK

10,19
4
15(1)
11,17,18(2,3)
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2,9
13
10
1,7
10
7
3
5,6,7,12,14,15
15(1)
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10,16(1)
8,16(2-7),20
18(1)
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Perfect world scenario Supersite1 in red, 2 in
blue, 3 in brown, 4 in green
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Weather radar network

• DWD Karlsruhe radars are operated
  continuously(volume 10 min update).
• S-Pol Poldirad (volume 10 minute update
  anticipated).
• Vertical scans (RHI) in predefined directions.

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Polarimetric radar and MRR transect

• Observation of the modification of the RDSD by
  orography.

MRR_1
MRR_3
MRR_2
MRR_4
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Next steps

• State of participitation of S-PolKa ?
• Location for POLDIRAD and S-PolKa ?(S-PolKa 6
  weeks, POLDIRAD 3 months)
• Location of supersites (S1, S2, S3, S4)
• Update list of other instruments- GOP
  precipitation instruments- SOP precipitation
  instruments
• Refine location of precipitation instruments
  (with respect to radars and supersites)
• What output is required for data assimilation ?