A DEPLOYABLE MODULAR WIND PROFILER RADAR FOR LOWER ATMOSPHERE APPLICATIONS William Brown, Steve Cohn, Brad Lindseth National Center for Atmospheric Research Boulder, Colorado, USA With help from: Jim Jordan, Dan Law, Warner Ecklund NOAA 9 th ISTP L’Aquila, Italy. 3-7 September 2012

NCAR : Earth Observing Laboratory Operates a wide range of instruments and aircraft for the scientific community Available by request to National Science Foundation

Current radar wind profilers Four LAP3000 profilers 915 MHz 400W (+ 1290MHz) Boundary layer only Clutter screen Older technology DBS Winds 15 – 30 minutes

Typically deployed with Integrated Sounding System DYNAMO / CINDY Indian Ocean MJO Study

Wide range of science targets But: Inflexible One size fits all Wind Profilers : 40+ projects Common Science Targets Tropical storms and dynamics Severe storms and fronts Mountain-valley flows Winter storms Lake and marine effects Ice/raindrop fall speed and evolution Boundary layer height and entrainment Turbulence effects on aviation safety

New: 449 MHz Wind Profiler

449 MHz Modular Wind Profiler Longer wavelength enables higher altitudes Fast wind measurements (spaced antenna) Modular to give more flexibility Combine modules to make radars of varying sizes Easy to deploy No clutter screen Light-weight modules Hexagonal Module

Boundary Layer Config. 3 antenna modules Network of 6 Mid-Tropospheric Config. 7 antenna modules Network of 2 Lower Stratospheric Config. 19 antenna modules 200 m – 7 km m 300 m – 15 km m Range: Resolution: 150 m – 4 km 30 m Not to scale! One module Modular Antennas With 19 modules :

Example: T-REX

First deployment of 3-antenna prototype PCAPS (Persistent Cold Pool Study) Salt Lake, Utah, Dec Feb 2011 Side-by-side comparison: 915 MHz wind profiler 449 MHz wind profiler (3 modules, 2kW) 449 MHz Wind Profiler 915 MHz Wind Profiler

449 MHz 915 MHz 449 Profiler Winds 2-month deployment Hardware performed well 449 Better altitude coverage than 915 Better time resolution Captured the interface between valley flow and mountain crest flow (important for PCAPS science) Comparisons 24 hours  4 km 

449 MHz Comparison with 915 MHz High 915 Low Winds percentage vs. Height Altitude coverage about 1 km greater 2 months Median absolute difference < 1.5 m/s

449 MHz: 5-minute winds Fast wind measurement enables study of rapidly evolving events Squall over Boulder w 2 hours  10 km 

Wind Profiler: 449 MHz radar Latest developments Expansion to 7 panels So far using: 2 kW TX amp 3 channel data system Coming soon: 16 kW TX amp 7 channel data system Winds thru much of troposphere

7-panel first obs Winds to 6 – 8 km in clear-air Twice as high as 915MHz 449 MHz 915 MHz Sonde

Next step: RIM Range IMaging Enables improvement in range resolution Small inter-pulse steps in wavelength Aiming to go from 150 m down to < 50 m

Summary  Prototype systems working well  Completing seven antenna modules o One 7-panel profiler OR two 3-panel systems (Two BL or one mid-troposphere profiler)  Next Steps o Adding power (up to 16 kW) o Adding channels (3 -> 7) o Improving lower levels o Improve processing and QC o Adding RIM  Three user proposals received already  Longer term:  Mobile truck based profiler, RASS (T v )  Considering how to adapt for ship operations  Eventually…develop full 19-module system