Toward an Integrated Air-Sea Real-Time Airborne Observing System for Landfalling Hurricanes

1. Toward an Integrated Air-Sea Real-Time Airborne Observing System for Landfalling Hurricanes Peter G. Black, Eric Uhlhorn and John Gamache NOAA/AOML/Hurricane Research Division Al Goldstein, NOAA/AOC, Ivan Popstefanija, ProSensing. Inc. Jim Carswell, Remote Sensing Solutions, Inc., Paul Chang, NOAA/NESDIS Edward Walsh, NASA Goddard at NOAA/ESRL Nick Shay, Univ. of Miami, RSMAS/MPO 61st Interdepartmental Hurricane Conference New Orleans, LA March 5-9, 2007

2. The Evolving SystemThe Bridge Across the Valley of Death • AFRC WC-130J • SFMR: 3-5 units, 2007; all 10 units, 2008 • AOC GIV • TA Doppler, SFMR 2008-09 • AOC WP-3D N43RF • SFMR, TA Doppler NOW;SRA 2007, HIRad 2009 • AOC WP-3D N42RF • SFMR, TA Doppler, IWRAPNOW;AWRAP 2008 2002 IHC- Defining the Valley; 2007 IHC- Building the Bridge

3. SFMR measures C-band microwave emission from foam (air bubbles in the ocean) First flight: Allen, 1980 22 years to assemble bridge components 2003: First OFCM/ AOC bridge- operational SFMR on WP-3D 2004-08: The ‘Golden Gate’ Congressional bridge

4. The Evolving System- Capability • SFMR- Surface wind speed and rain rate along track • TA Doppler- 3D wind vector, reflectivity ± 70 km from track; 1-10 km altitude • IWRAP- Surface wind vector and rain rate swath ± 3-5 km from track to 50 m/s; boundary layer 3D wind vector vertical profile along track- 30 m to flight level • AWRAP- Operational version of IWRAP with dual pol • SRA- Surface directional wave spectrum along track: direction, height and wavelength of 3 wave components in real time. • HIRad (next-generation SFMR)- Surface wind speed and rain rate ± 5-8 km from track for WP-3D; ± 40 km from hi level AUV); wind direction in 3-4 years

5. The Evolving System- Progress • SFMR- • Major wind model upgrade, remove high wind low bias and moderate wind high bias- Uhlhorn, 2005 • Major rain model upgrade- Carswell, 61st IHC-2007 • Major cal upgrade, warm load- ProSensing, 2005 • Add hires land mask, weekly SST field via web uplink- Goldstein • WC-130J fleet SFMR install begins- April, 2007; 3-5 systems by Sept; all 10 by Feb, 2008 • SFMR purchase for GIV • JHT support for calibration, validation and performance improvements in fetch-limited, shallow water conditions: 2005-2007 • Canted off-nadir SFMR installation on N43RF for HIRad algorithm development (?)

6. The Evolving System- Progress 2 • SRA • Real time algorithm development, 2004-05 • SBIR Phase II award (ProSensing) for operational system, 2006 • Operational SRA install and flight tests, 2007 • AWRAP • SBIR Phase II award (Remote Sensing Systems) for operational IWRAP, 2006 • AWRAP install and flight tests, 2008 • G-IV operational TA Doppler and SFMR • Install and flight tests, 2008

7. Reducing Wind Field Uncertainty • SFMR flight track strategies • Alpha pattern normal to storm track • Rotated Alpha or ‘Butterfly’ pattern • SFMR cal improvements; shallow water, coastal algo refinements, rain rate algo refinements (JHT supported) • HIRad- broaden SFMR line to a swath enhancing probability of detecting true surface wind max

8. TA Doppler 23 deg fore/aft scan 70 m pulse AWRAP Frequency: C-band & Ku-band Polarization*: VV, HH, HV & VH Beam Incidence Angles: 30, 35, 41.5, 50 Altitude Range: 500 – 8000 m Range Resolution: 15, 30, 60 & 120 m AWRAP Four channel receiver records Doppler & reflectivity profiles for all four beams simultaneously SRA swath HIRAD Swath: 30-60 deg Conical Scan (60 rpm, 15 m pulse) SFMR 6 frequencies Half Beam: 0 to 10, 12 deg Swath Coverage ~25 – 55 deg. incidence

9. Hurricane Katrina- SFMR 28 Aug - Peaked profile Vmax=142 kt 29 Aug - Flat profile Vmax=100 kt 29 August 28 August * SFMR surface wind — 700 mb flight-level wind ° 700 mb Gradient Wind - - Radial wind • - Vmax NHC estimate Diamond - Vmax Press/Wind Square - GPS 10-m estimate Triangle - GPS 10-m measurement

10. NOAA WSR-88D Radar NOAA GOES IR Satellite Air Force WC-130J Flight Level NOAA WP-3D SFMR NOAA WP-3D DOPPLER

11. NOAA SFMR 29 Aug 0930 UTC Air Force 29 Aug 0930 UTC

12. Doppler Wind Profile - 28 Aug 1725-1820 UTC 12 km SW NE Flight Level 1 km Doppler Wind Profile - 29 Aug 1000-1040 UTC 12 km W NE Flight Level 1 km Dramatic 12-h change in Katrina Wind Profile: CAT5-CAT3

13. 6 6 9 9 Inflow and shallow wind max to West Outflow and deep wind max to East • Doppler analyses from 1st W-E leg during Katrina landfall showing asymmetry in horizontal and vertical wind distribution 12 km Flight Level 1 km Doppler Winds at 1 km altitude. Peak winds right of track on inbound leg and left of track on outbound leg

14. Hurricane Rita Sept 21 Sept 22 Sept 23

15. Hurricane Michael 1930 GMT, 18 Oct, 2000 AFRC 850 mb flight level reduction (left) SFMR surface measurement (right)

16. GPS Dropsonde - Volume Sampled IWRAP inner & outer swath limits 2000 1500 1000 500 0 Dropsonde trajectory Altitude of GPS Dropsonde [m ] Altitude (m) Ground Track 0 2300 m 15 10 5 0 Distance from aircraft [km ]

17. Preliminary Wind Profile Validation Comparison C-Band VV 31.5 degrees incidence to 6 consecutive dropsondes WIND SPEED WIND DIRECTION 2000 1500 1000 500 0 2000 1500 1000 500 0 Flight level Dropsondes IWRAP Altitude SFMR 100 80 60 40 20 0 [deg] 50 60 70 80 90 100 [m/s] Isabel: Sept. 12, 2003, 18:42:20 to 18:43:42 Z

19. Uni-modal Tri-modal Bi-modal Surface Wave Topography Types

20. Hurricane Ivan The center of the figure shows wind speed contours (m/s) from the HRD HWIND surface wind analysis- based mainly on SFMR surface wind speed measurements in Hurricane Ivan at 2230 UTC on 14 September 2004 for a 2｡ box in latitude and longitude centered on the eye. Arrow at the center indicates Ivan’s direction of motion (330ｼ). The storm-relative locations of twelve 2D surface wave spectra measured by the SRA are indicated by the black dots. The spectra have nine solid contours linearly spaced between the 10% and 90% levels relative to the peak spectral density. The dashed contour is at the 5% level. The outer solid circle indicates a 200 m wavelength and the inner circle indicates a 300 m wavelength. The dashed circles indicate wavelengths of 150, 250, and 350 m (outer to inner). The thick line at the center of each spectrum points in the downwind direction, with its length proportional to the surface speed. The upper number at the center of each spectrum is the significant wave height and the lower number is the distance from the center of the eye. The average radial distance for the twelve spectral locations is 80 km.

21. HIRad Concept NOAA’s Gulfstream-IV SP SFMR Swath HiRad Swath  Concept • HIRad offers wide swath and high resolution imaging from Gulfstream IV or a UAV. • Potential for spaceborne application.  Technology • The multi-frequency, microstrip, stacked patch, thinned array is the technology challenge for HIRad. HIRad wind speed simulation of Hurricane Floyd

22. In-Situ Measurements Expendable Probe Deployment • WP-3D • GPS Dropsonde • AXBT • AXCTD • AXCP • WC-130J • GPS Dropsonde • Floats • ADOS: Tz chain to 100 m • Minimet: surface winds, currents • Drifting Buoys • SOLO • Lagrangian • EM-APEX

23. Atmospheric Profiling GPS Dropsondes

24. Ocean Thermal Structure in Floyd

25. Rita 26C Depth from AXCP, AXCTD, AXBT Data

26. ADOS/SVP Minimet drifter AFRC/53rd WC-130J Hercules

27. Hurricane Frances (2004) float and drifter array. Orange line shows storm track labeled by date/time (triangles = 6-hr positions). Blue circles=drifters; magenta squares=lagrangian; green circles=EM-APEX; red stars=ARGO/SOLO. Deployment position is indicated by black symbol.

28. CONCLUSION We are at a historic turning point in history for improving hurricane intensity observation and forecasting where the capability to observe the coupled hurricane-wave-ocean domain matches the improved coupled model capabilities to assimilate and model atmospheric, ocean and interface variables. This alignment should provide the next best opportunity for improving hurricane intensity and structure forecasting.