GV for Snowfall Retrieval Research

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GV for Snowfall Retrieval Research

• David Hudak
• Paul Joe

2nd International GPM Ground Validation Workshop,
27-29 September, Taipei, Taiwan
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Ref WMO Publication No. 9 Volume A
All active Synoptic Stations north of 50 N
29 Oct 2001
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POSS Occurrence(1 minute data)
YEVInuvik 68N YULMontreal 45N

• Surface obs
• Doppler XBand
• Derived Snowrates
• Minutely
• Snow only
• Typed by observer
• 1 winter of data

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Vertical Profile Analysis
Fort Simpson (62N)
Montreal (45N)
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Quantifying Snow Gauge Errors

• Systematic errors
• WIND (temperature)
• wetting loss
• evaporation loss
• non-zero trace
• capping of gauge orifice
• blowing snow

Goodison et al
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WMO Intercomparison Study Results Catch
Efficiency vs Wind for the 4 most widely used
gauges
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Precipitation Occurrence Sensing System (POSS)

• XBand
• Bistatic
• Continuous Wave

• Doppler
• Mie Scattering
• Terminal Velocity

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POSS Research Applications Quantitative
Precipitation Estimation (QPE)
Under over

• Solid precipitation rate validation using the
  Double Fence Intercomparison Reference (DFIR)

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POSS Research ApplicationsQPE Snow Density
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POSS Research ApplicationsAirport Vicinity Icing
and Snow Advisor (AVISA)
NCAR/DRI Hot Plate
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Centre fo Atmospheric Research Experiments EC
field project deployment suite
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NRC Airborne W/X band radar (NAWX)

• Fully Polarimetric and Doppler
• W-band Five ports Electronic switching
• X-band Two ports - Electronic switching

• W-band
• Nadir and Vertical-up Z, LDR, Vd
• Vertical-up side Polarimetric, Vd
• Nadir-Side Polarimetric, Doppler
• Nadir Nadir-aft Dual-Doppler
• Side Side-forward Dual-Doppler

• X-band
• Nadir and vertical-up Single polarization
• Side - Polarimetric

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CONVAIR-580 CLOUD MICROPHYSICS (cntd)
Under-wing particle probes
Standard PMS 2D Imagery
6400 um
800 um
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POSS Research ApplicationsPrecipitation
TypingDoppler Spectral Mode Analysis
RAIN
SNOW
Mixed SNOW RAIN
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King City C-band Dual Polarized radar
Correlation Coefficient ?hv
ZR-IP-
S
YHM
YKF
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C-band Polarization parameters
Correlation Coefficient ?hv
Reflectivity Z
Differential Reflectivity ZDR
Specific Differential Phase kdp