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

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

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

The Evolving System- Capability SFMR- Surface wind speed and rain rate along track SFMR- Surface wind speed and rain rate along track TA Doppler- 3D wind vector, reflectivity ± 70 km from track; 1-10 km altitude 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 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 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. 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 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

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

The Evolving System- Progress 2 SRA SRA –Real time algorithm development, –SBIR Phase II award (ProSensing) for operational system, 2006 –Operational SRA install and flight tests, 2007 AWRAP 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 G-IV operational TA Doppler and SFMR –Install and flight tests, 2008

Reducing Wind Field Uncertainty SFMR flight track strategies 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) 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 HIRad- broaden SFMR line to a swath enhancing probability of detecting true surface wind max

AWRAP Four channel receiver records Doppler & reflectivity profiles for all four beams simultaneously Conical Scan (60 rpm, 15 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 Swath Coverage ~25 – 55 deg. incidence SFMR 6 frequencies Half Beam: 0 to 10, 12 deg SRA swath HIRAD Swath: deg TA Doppler 23 deg fore/aft scan 70 m pulse

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

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

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

Dramatic 12-h change in Katrina Wind Profile: CAT5-CAT3 Doppler Wind Profile - 29 Aug UTC W NE Doppler Wind Profile - 28 Aug UTC 1 km SWNE Flight Level 1 km Flight Level 12 km

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

Hurricane Rita Sept 21 Sept 22 Sept 23

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

GPS Dropsonde - Volume Sampled Distance from aircraft [km ] m Altitude (m) Ground Track Altitude of GPS Dropsonde [m ] IWRAP inner & outer swath limits Dropsonde trajectory

Preliminary Wind Profile Validation Comparison C-Band VV 31.5 degrees incidence to 6 consecutive dropsondes [m/s] [deg] Flight level SFMR IWRAP Dropsondes WIND SPEEDWIND DIRECTION Isabel: Sept. 12, 2003, 18:42:20 to 18:43:42 Z Altitude

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

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. Hurricane Ivan

HIRad Concept HiRad Swath NOAA’s Gulfstream-IV SP SFMR Swath HIRad wind speed simulation of Hurricane Floyd  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.

Expendable Probe Deployment WP-3D WP-3D –GPS Dropsonde –AXBT –AXCTD –AXCP WC-130J WC-130J –GPS Dropsonde –Floats ADOS: Tz chain to 100 mADOS: Tz chain to 100 m Minimet: surface winds, currentsMinimet: surface winds, currents –Drifting Buoys SOLOSOLO LagrangianLagrangian EM-APEXEM-APEX In-Situ Measurements

Atmospheric Profiling GPS Dropsondes

Ocean Thermal Structure in Floyd

Rita 26C Depth from AXCP, AXCTD, AXBT Data

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

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.

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.