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Transition of Radar Refractivity to Operational Radars. Interested parties: NCAR, McGill University, NEXRAD Office of Science and Technology, Federal Aviation Administration, and University participants??. OS&T Briefing, 6 April 2004. REFRACT T.
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Transition of Radar Refractivity to Operational Radars Interested parties: NCAR, McGill University, NEXRAD Office of Science and Technology, Federal Aviation Administration, and University participants?? OS&T Briefing, 6 April 2004
REFRACTT Refractivity Experiment For H2O Research And Collaborative operational Technology Transfer
Forecasting Challenge:Tracking the “pockets” of boundary layer moisture so critical for convection initiation and growth. Moisture gradient Moisture gradient Convergence boundaries Convergence boundaries 00:40 UTC 00:40 UTC 22:57 UTC 00:31 UTC 00:01 UTC 00:31 UTC 22:57 UTC 00:01 UTC 23:27 UTC 23:27 UTC Moisture gradients and convergence boundaries associated with thunderstorm development, June 12, 2002
Why REFRACTT • Demonstrate feasibility on operational radars and motivate • NWS and FAA to install refractivity on WSR-88D and TDWR • Demonstrate forecast improvement in models and very • short period forecasting techniques over a larger domain • Improve basic understanding of the role of water vapor • in convective storm initiation and storm evolution • This is technology transfer of IHOP results to the operational community
100 km Boundary Install refractivity on the national network of radars S-Pol Radar 0 km WSR-88D’s TDWR Radars TV Radar (Local Station) Surface Mesonets NWS/ResearchSoundings AERI: ARM/CART -100 km -100 km 0 km 100 km Satellite FOV Satellite Derived Products: CAPE, CIN LI, Precipitable Water, Soundings Spring 2006 Oklahoma REFRACTT Refractivity Experiment For H20 Research And Collaborative operational Technology Transfer
FAA Radar Networks λ = 5 cm PT = 250 kw 0.5° pencil beam λ = 10 cm PT = 1000 kw 1.4° x 5° fan beam Future: Install refractivity on all available operational radars
Cost Function VDRAS Boundary Layer Winds Old New equation Assimilation of Refractivity into VDRAS Juanzhen Sun • Test technique using IHOP data to produce stability fields (CAPE, CIN, and moisture) • Test use of VDRAS stability fields in the Auto-Nowcaster
Comparison of Refractivity Observations with High Resolution Land Data Assimilation System (HRLDAS) 16:00 16:00 Refractivity Soil Moisture 18:00 18:00 Refractivity Soil Moisture Refractivity Hourly HRLDAS Evaporation (mm) Collaborative studies with Fei Chen IHOP 25 May 2002
Data Processing: IHOP “Climatology” Broad WNW-ESE refractivity and daily N gradient observed. Mimics (reflects?) climatological moisture gradient in the area.
Small-Scale Structure of N Lesser variability in along-wind direction than across: • More mixing in along-wind direction via surface friction? • More advection-driven E-W gradients (across wind).
Timeline 2003 2004 2005 2006 2007 Prototype Development Refractivity on S-Pol’s RVP8 Prototype development on TDWR and ASR-9 ORDA (RVP8) installation Prototype installation and testing on NSSL’s KOUN Prototype installation and testing on ROC’s KCRI Operational Radar Refractivity Test
S-Pol refractivity VDRAS convergence field at z=0.187 km Results from IHOP June 12 case study
Z=0.187 km Retrieved water vapor fields for the first three model levels Z=0.937 km Z= 0.562 km
Where are we currently ? • Received the support of the NEXRAD TAC at the 28 October 2003 meeting. • Coordinating with Bob Saffle on writing documentation for NWS Stage 1 and Stage 2 documents • Weber and Parker (MIT/LL) have received high level (verbal not monetary) support for testing the refractivity technique on the TDWR testbed radar in OKC. • Submitted a preliminary letter of intent to NCAR/ATD to request the SPol radar for REFRACT 2006
Piggy-back on the HEAT 2005 Experiment? • Install refractivity on CHILL and the ?? Radar
NCAR SPol Ground Clutter Map Oklahoma Panhandle – IHOP2002 Would like to see similar by-pass filter maps for selected NEXRAD radar sites. Cheryl Stephenson and Dave Zittel at ROC have been contacted.
GROUND CLUTTER PATTERNS OKC TDWR TESTBED SITE 50 km range ring
Observations of a Gust Front Refractivity Reflectivity