Development of Mobile Radars for Hurricane Studies Michael Biggerstaff School of Meteorology National Weather Center 120 David L. Boren Blvd.; Norman OK 73072
Univ. Massachusetts W-band dual-pol X-band dual-pol CIRPAS X-band phased array CSWR (2) X-band Doppler (1) X-band multi-beam Univ. Connecticut X-band dual-pol Florida State Univ. C-band dual-pol U. Alabama-Huntsville X-band dual-pol Texas Tech Univ. Ka-band Doppler Univ. Oklahoma C-band Doppler (SR1) C-band dual-pol (SR2) X-band dual-pol (NOXP) Many Mobile Systems Exist
Iowa State University (4) X-band dual-pol systems Texas Tech Univ. Second Ka-band Doppler Univ. Massachusetts Ka/Ku/W band OU ARRC X-band imaging radar X-band dual-pol rapid-scan frequency-agile system And More Are On the Way
National Infrastructure Mobile Weather Radars In All 21 mobile radars! 14 X-band mobile radars 2 Doppler (single-beam single-pol) 9 dual-pol (one a rapid scanning system) 1 multi-beam (rapid scanning) 1 phased array (rapid scanning) 1 imaging (simultaneous snap shot 2D) 3 C-band 1 Doppler 2 dual-pol 1 W-band 2 Ka-band 1 triple band
Shared Mobile Atmospheric Research and Teaching (SMART) Radar Program Collaboration OU, NSSL, Texas A&M, TTU Mobility Rapidly deployable (~ minutes) Targeted operations (user configurable) Self sustaining platform Durability Hurricane winds (~90 knots) Snow storms Deserts
Current SMART Radar Characteristics Truck mounted C-band Doppler radar 2.4 m diameter antenna (1.5 beam) Linear horizontal polarization; one-system has simultaneous dual-pol (STaR) option (scheduled for March 09) 250 kw magnetron transmitter 10 kw diesel generator Measures reflectivity, velocity, spectrum width, I&Q time series, differential radar reflectivity factor, differential phase shift, linear depolarization ratio, correlation coefficient; real-time data delivery Radial resolution selectable up to 25 m Full or sector PPIs (up to 6 rpm); selectable RHIs (zero to 90 ) DVD archive; RAID archive for I&Q
Recent Addition NOXP-Simultaneous Transmit and Receive NOXP at Brazoria County airport during Ike land fall Truck mounted X-band dual-polarimetric Doppler radar 2.4 m diameter antenna (0.9 beam, ~28 db cross-pol isolation) 200 kw magnetron transmitter (100 kw in each channel) 10 kw diesel generator Measures reflectivity, velocity, spectrum width, I&Q time series, differential radar reflectivity factor, differential phase shift, correlation coefficient Radial resolution selectable up to 25 m Full or sector PPIs (up to 5 rpm); selectable RHIs (zero to 90 ) DVD archive; RAID archive for I&Q
Hurricanes Sampled by SMART/NOXP Single Doppler/Dual-pol deployment 2001 Gabrielle (BL structure) 2002 Isidore, Lilly (BL rolls and HBL transition) 2008 Ike (Landfall flooding) Dual-Doppler deployment 2003 Isabel (Internal dynamics) Biggerstaff et al. (2005) 2004 Frances (HBL transition; TC tornadoes) Back-Up to 88D Network; 2006-2008 Radar Reflectivity Vertical Motion Cross-section through Isabel Inner Band
Hurricane Research with Mobile Radar Data Mobile C-band Doppler radars on 55 km N-S baseline 12.5 hours of continuous sampling 16-tilt, 130 sector scans took 2.5 min. (4 sectors collected every 20 min) 16-tilt full volume scan took 4 min. (every 10 min) Coordinated with TTU towers Radar Reflectivity Vertical Motion
Inland Flooding Notable variability in rainfall distribution Max rain farther inland 24-hour totals not particularly impressive near coast What internal circulations are responsible for the rainfall distribution? Radar Reflectivity Vertical Motion 24 hour accumulated rainfall estimated by Moorehead, NC WSR-88D radar during landfall of Hurricane Isabel 2003
Internal Dynamics- Outer Bands Retrieved Track-Relative Flow at 1.5 km Vertical Motion Radar Cellular Reflectivity vertical drafts consistent with reflectivity pattern Vertical draft peak magnitudes ~2-3 m/s common Scale of connecting band reflectivity similar to scale of the lowlevel updraft
Internal Dynamics Eyewall Retrieved Track-Relative Flow 3.0 km CAPPI of eyewall structure Vertical Motion Vertical cross-section Radar Reflectivity Failed eyewall replacement cycle prior to landfall; radius of max wind well outside strongest convection. through eyewall Modest updrafts and weak donwdrafts
Current Plans 2009 Debris Flow (Dec. 08 - March 09; SR1) VORTEX2 phase 1 (May-June; all 3 radars) Hydrometeorology Project (July Sept.; NOXP) Rebuild SR2 Transmitter/Receiver and finish dual-pol upgrade (July Sept.) Rebuild NOXP Transmitter/Receiver (Oct.- Dec.) 2010 Debris Flow (Dec. 09 March 10; SR2) Take delivery of RapidXpol by March VORTEX2 phase 2 (May - June; all 3 radars plus RapidXpol) DoE/ARM West Pacific (Sept. 2010 - March 2011; SR1) Finish OU AIR (ARRC Imaging Radar; Aug.) TC at landfall (Aug. - Oct; SR2 and RapidXpol; maybe AIR&SR1) 2011 Debris Flow (Dec. 10 - March 11; SR1) DC3 (May-July; SR1&2 plus NOXP) TC at landfall (Aug. Oct.; all radars)
Summary Numerous mobile radars exist or in active development phase; more expected Mobile radars can provide 3-D winds and quantitative rainfall estimates over large regions with high fidelity in time and space Land-falling Tropical Cyclones potentially targeted for 2010 (Aug. - Oct.) with RapidXpol and SR2 (funding available). More radars are available but would require collaborative effort and additional funds. Larger field effort could be planned for 2011 and beyond with all five radar systems (SR1, SR2, NOXP, AIR, RapidXpol) Large coordinated field program to study land-falling TCs is sorely needed; meanwhile piece-meal uncoordinated deployments by numerous investigators will continue
Questions? SR1 Deployment during Isabel 2003 Point of Contact: Dr. Michael Biggerstaff University of Oklahoma; drdoppler@ou.edu