A NEW SAR RETRIEVAL METHOD FOR HURRICANE WIND PARAMETERS REMOTE SENSING TECHNOLOGIES INSTITUTE Antonio Reppucci, Susanne lehner, Johannes Schulz-Stellenfleth German Aerospace Center (DLR) Oberpfaffenhofen 82234 Wessling, Germany. SEASAR 2008, Frascati
Hurricane Katrina Buoys wind speed : A: Measured=14.4 m/s SAR Retrieved =13.3 m/s B: Measured=15.8 m/s SAR Retrieved =17.1 m/s *A * B REMOTE SENSING TECHNOLOGIES INSTITUTE Radius of Maximum Wind (70 m/s). Radius of Hurricane force Wind (33 m/s). Strong Convective Cell SEASAR 2008, Frascati
Overview •Measurement of Tropical Cyclone Intensity •Wind Speed Error REMOTE SENSING TECHNOLOGIES INSTITUTE •New procedure to estimate TC intensity using SAR data •NRCS attenuation in hurricane •Conclusion. SEASAR 2008, Frascati
Dvorak Technique Operational since 1973 The technique utilizes the difference between the temperature of the warm eye and the surrounding cold cloud tops from IR images and the fact that cyclones of similar intensity tend to have certain characteristic CI MWS MSLP features. From these measurements a Current Intensity (CI) value is number (kts) (hPa) assigned to the storm . REMOTE SENSING TECHNOLOGIES INSTITUTE 1.0 25 - - - 1.5 25 - - - [Dvorak, V., 1984: Tropical cyclone intensity analysis using satellite data. NOAA Tech. 2.0 30 1009 Report NESDIS 11. Available from NOAA/NESDIS, 5200 Auth Rd., Washington DC, 20233, 47pp. ] 2,5 35 1005 3,0 45 1000 3,5 55 994 4,0 65 987 4,5 77 979 5,0 90 970 5,5 102 960 6,0 115 948 6,5 127 935 7,0 140 921 7,5 155 906 8,0 170 890 SEASAR 2008, Frascati
Airplane Measurement Operational Hurricane Katrina 28/08/2005 NOAA P3 and G4 research aircraft GPS dropwindsondes: REMOTE SENSING TECHNOLOGIES INSTITUTE � pressure � humidity � temperature � wind direction and speed Stepped-Frequency Microwave Radiometer � Wind speed � Rain Rate [Uhlhorn, Eric W., Peter G. Black, James L. Franklin, Mark Goodberlet, James Carswell, Alan S. Goldstein, 2007 : Hurricane Surface Wind Measurements from an Operational Stepped Frequency Microwave Radiometer, Monthly Weather Review, In press] SEASAR 2008, Frascati
Active Microwave Wind Speed Measurements SeaWinds ASAR Hurricane Katrina 29-08-2005 Hurricane Katrina 28-08-2005 (c) JPL REMOTE SENSING TECHNOLOGIES INSTITUTE m/s C band K u band SEASAR 2008, Frascati
Rain in Tropical Cyclones REMOTE SENSING TECHNOLOGIES INSTITUTE SEASAR 2008, Frascati
Rain Rate by HOAPS REMOTE SENSING TECHNOLOGIES INSTITUTE Image courtesy UNI Hamburg, MPI SEASAR 2008, Frascati
SFMR rain rate measurements NOAA HRD Hurricane Katrina 28/08/2005 REMOTE SENSING TECHNOLOGIES INSTITUTE SEASAR 2008, Frascati
Rain attenuation Ku band C band Delta NRCS Delta NRCS REMOTE SENSING TECHNOLOGIES INSTITUTE Undisturbed NRCS Undisturbed NRCS [Z.S. Haddad, David A. Short, Stephen L. Durden, [Ulaby F.T., More R.K., Fung A.K, 1981, Eastwood Im,Scott Hensley, Martre B. Grable, and Robert Microwave Remote Sensing: Active and Passive A. Black,(1997). A New Parametrization of the Rain Drop (MA: Addison-Wesley) , vol. 1.] Size Distribution, IEEE Trans. Geosci. Remote Sensing , vol. 29,pp. 690–703, Sept. 1997.] SEASAR 2008, Frascati
NRCS err. on wind speed retrieval CMOD-5 REMOTE SENSING TECHNOLOGIES INSTITUTE [Hersbach H., 2003, CMOD5 an improved geophysical model function for ERS C- band scatterometry, Internal report, European Centre for Medium- Range Weather Forecast , no. 395. ] Wind direction [deg] Wind speed [m/s] Simulation of NRCS Attenuation Retrieval of wind speed for different wind speed of the simulated using attenuated and direction NRCS of 0.5 dB NRCS SEASAR 2008, Frascati
Wind Speed error CMOD5 Inc.=25° Cross wind CMOD5 Inc.=25° NRCS [dB] Up wind NRCS [dB] CMOD5 CMOD5 Inc.=25° Inc.=25° Cross wind REMOTE SENSING TECHNOLOGIES INSTITUTE Up wind Att.=0.5 dB Att.=0.5 dB Wind speed [m/s] Wind speed [m/s] Second Solution Wind speed [m/s] Wind speed [m/s] First Solution Wind speed [m/s] Wind speed [m/s] SEASAR 2008, Frascati
Error Map Wind speed [m/s] REMOTE SENSING TECHNOLOGIES INSTITUTE Inc. Angle 25° Wind direction [deg] Wind speed [m/s] Inc. Angle 35° Wind direction [deg] SEASAR 2008, Frascati
Holland Model AOML-HRD Wind Field 1 ⎡ ⎤ ⎛ ⎞ B − A / r 2 Wind speed [m/s] ⎢ 2 ⎥ ⎜ ⎟ exp A ⋅ B ⋅ p − p f r ⋅ f n c 2 ⎢ ⎝ ⎠ ⎥ V = + r ⋅ − ⎢ ⎥ r B 4 ⎢ ⎥ 2 ρ ⋅ r ⎢ ⎥ ⎣ ⎦ REMOTE SENSING TECHNOLOGIES INSTITUTE � p c = Central Pressure � p n = Environment pressure � r = distance from the center � f = Coriolis parameter � ρ = Air Density Wind speed [m/s] � A,B = Scaling Parameter related to R mws [G.J. Holland, 1980, An Analytic model of the wind and pressure profiles in Hurricanes, Mon. Weather Rev., vol. 108, pp. 1212–1218. ] Simulation of Katrina Wind Field SEASAR 2008, Frascati
Along Track Cut REMOTE SENSING TECHNOLOGIES INSTITUTE Holland simulated NRCS Radius maxmimum Measured NRCS wind speed SEASAR 2008, Frascati
New Method to Estimate the Maximum Hurricane Wind Speed o ( ( ) ) p , v CMOD5 ( θ , φ ) Holland Model( p c ,v M ) σ c M [ ] 2 ( ) = ∑ o o , σ p v − σ ( ) i c M i J p , v c M [ ] 2 REMOTE SENSING TECHNOLOGIES INSTITUTE o σ i i o σ = Measured NRCS i o ( ( ) ) p , v σ = Holland simulated NRCS c M p c = central pressure v M = maximum wind speed Holland fitted wind speed CMOD5 Retrieved wind speed tropical storm force winds SEASAR 2008, Frascati
New Method to Estimate the Maximum Hurricane Wind Speed Acquisition Image center Measured Max SAR Retrieved Measured SAR Retrieved Time Coordinates Wind Speed Max Wind Speed Central Central Pressure Pressure 26,1 ° N, 87.7 ° W Hurricane Katrina 28-08-05 15:50 70 m/s 68 m/s 905 mb 901 mb 23.5 ° N, 85.5 ° W Hurricane Rita 22-09-05 03:45 75 m/s 70 m/s 897 mb 890 mb 18.3 ° N, Typhoon Kiko 09-09-05 01:11 45 m/s 48 m/s 955 mb 950 mb 131 ° E REMOTE SENSING TECHNOLOGIES INSTITUTE 29.4 ° N, 124.2 ° E Typhoon Kiko 11-09-05 01:46 55 m/s 60 m/s 945 mb 930 mb 28.8 ° N, 128.4 ° E Typhoon Songda 06-09-04 13:23 44 m/s 40 m/s 945 mb 946 mb SAR Retrieved Central Pressure SAR Retrieved Max Wind Speed Measured Max Wind Speed Measured Central Pressure SEASAR 2008, Frascati
NRCS att. Katrina 28-08 2005 Wind speed [m/s] NRCS [dB] REMOTE SENSING TECHNOLOGIES INSTITUTE Delta NRCS [dB] Inc. Angle: 33.9° NRCS meas [dB] SEASAR 2008, Frascati
REMOTE SENSING TECHNOLOGIES INSTITUTE Wind speed [m/s] Delta NRCS [dB] NRCS att. Kiko 09-09 2005 NRCS meas [dB] NRCS [dB] SEASAR 2008, Frascati Inc. Angle: 37°
Conclusions and future steps • Wind Speed retrieval in Hurrican force winds shows a Limited skill in intensity analysis. • Rain contamination can partly explain the strong damping but also the foam layer must be taken into account. • A new Procedure for the estimation of Tropical Cyclone Intensity using SAR data and parametric model results has REMOTE SENSING TECHNOLOGIES INSTITUTE been developed. • First analysis of the NRCS predicted by the CMOD5 GMF seems not agree with SAR measurements for high wind speed conditions. • Validation of the developed algorithm using more SAR Hurricane images. • Estimation of a possible correction to apply to the GMF CMOD5 for Tropical Cyclones conditions. • Application to extratropical Cyclones. SEASAR 2008, Frascati
REMOTE SENSING TECHNOLOGIES INSTITUTE Thanks for your Attention SEASAR 2008, Frascati
Ocean Surface in a Hurricane Images courtesy NOAAA HRD REMOTE SENSING TECHNOLOGIES INSTITUTE 200 m 200 m Wind speed ~28m/s Wind Speed ~ 46 m/s SEASAR 2008, Frascati
REMOTE SENSING TECHNOLOGIES INSTITUTE SEASAR 2008, Frascati
Rain Attenuation REMOTE SENSING TECHNOLOGIES INSTITUTE Attenuation Coefficient Volume Backscattering Coefficient Reflectivity Factor [ J. Tournadre, Y. Quilfen, 2003] SEASAR 2008, Frascati
Objective • Estimation of TC parameter using SAR data. REMOTE SENSING TECHNOLOGIES INSTITUTE • Improve the existing models for the wind speed retrieval In Tropical Cyclones conditions. SEASAR 2008, Frascati
Experimental techniques Objective Estimation of Tropical Cyclone Observational Analyses of North Atlantic Wind Structure from Infrared Satellite Data. Tropical Cyclones from NOAA Polar-Orbiting KIMBERLY J. MUELLER, MARK DEMARIA, JOHN KNAFF, JAMES P. Satellite Microwave Data KOSSIN, THOMAS H. VONDER HAAR. WEATHER AND Christopher S. Velden, Journal of Applied Meteorology , Volume 28, Issue 1 FORECASTING,dec 2005. (January 1989). REMOTE SENSING TECHNOLOGIES INSTITUTE [Katsaros K. B., Vachon P. W., Black P. G., Dodge P. P.,. Uhlhorn E. W., 2000, Wind Fields from SAR: Could They Improve Our Understanding of Storm Dynamics?, Johns Hopkins APL Technical Digest , vol 21, No. 1] SEASAR 2008, Frascati
Wind Speed error CMOD5 Inc.=35° CMOD5 Cross wind Inc.=35° Up wind NRCS [dB] NRCS [dB] CMOD5 CMOD5 Inc.=35° Inc.=35° Cross wind Up REMOTE SENSING TECHNOLOGIES INSTITUTE Att.=0.5 dB Att.=0.5 dB Wind speed [m/s] Wind speed [m/s] Wind speed [m/s] Wind speed [m/s] Wind speed [m/s] Wind speed [m/s] SEASAR 2008, Frascati
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