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Global/Oceanic Convection Diagnosis and Nowcasting

Global/Oceanic Convection Diagnosis and Nowcasting. Cathy Kessinger, Huaqing Cai, Matthias Steiner, Nancy Rehak, Dan Megenhardt National Center for Atmospheric Research Michael Donovan, Earle Williams Massachusetts Institute of Technology Lincoln Laboratory

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Global/Oceanic Convection Diagnosis and Nowcasting

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  1. Global/Oceanic Convection Diagnosis and Nowcasting Cathy Kessinger, Huaqing Cai, Matthias Steiner, Nancy Rehak, Dan Megenhardt National Center for Atmospheric Research Michael Donovan, Earle Williams Massachusetts Institute of Technology Lincoln Laboratory Richard Bankert, Jeffrey Hawkins Naval Research Laboratory – Monterey Sponsored by NASA ROSES Briefing to FAA and Airline Industry Representatives 8 April 2010

  2. Motivation: Air France 447 • Airbus A330 flying from Rio de Janeiro, Brazil to Paris, France • Departed 19:03 (2203 UTC) 31 May 2009 • Last automated messages received about 0214 UTC 1 June 2009 • 216 passengers and 12 crew lost • Black boxes not found; accident cause not yet determined • The wide-area view provided by real-time experimental Global Convection/Turbulence uplinks may have improved pilot situational awareness

  3. Air France 447 (0145 UTC 1 June 2009) Products developed by Oceanic Convection Diagnosis for deep convection Longwave IR BT Convection Diagnosis Oceanic (CDO) (approx.) Last ACARS message, 0214 UTC + (approx.) Last verbal contact, 0133 UTC Cloud Top Height (approx.) Last ACARS message, 0214 UTC + (approx.) Last verbal contact, 0133 UTC

  4. “Wx Ahead” Uplink Message valid 0130 UTC 1 June 2009 /EXP CLOUD TOP FI AF447/AN NXXXAF 01 Jun 09 -- '/' Cloud tops 30,000 to 40,000 ft//////CCC///// 'C' Cloud tops above 40,000 ft///////////CC///// *4.0N,30.0W///////// *////////C////////// //*//CC///CCC///////// ///*CCCC/C/CC////////// ////*CCCCCCC//C///////// ///CC*CCCCC///CC//////// ///CCC*CCCCC///////////// //CCCCC*CCCC////////////// //CCCCCCC*CCC////////////// /CCCCCCCCC*CCC///// / //CCCCCCCCCC*CC///// // /// //CCCCCCCCCCC*C///////// ////// /////CCCCCCCCCC*C// // // ////// //////CCCCCCCC//*/ // / ////// CC//////CCCCCCC//* ///////// CCC////////////// * ///////// /C//////////// *1.3N,31.4W //// /////// */ *// / /*/// // /*/// / /*// /*// * // * /// * // // * //// * ///// * ////// * ///// /// * /// Pos Rpt / // * / 0133 // X 1.4S,32.8W // Valid for // / 0130-0200z // Pilot feedback at url: http://[site deleted] 30-39Kft >40Kft /=30-39Kft C=>40Kft Graphical view (EFB concept) Text-based view for ACARS printer

  5. Motivation: Continental Airlines 128 • Boeing 767 flying from from Rio de Janeiro, Brazil to Houston, Texas, 3 August 2009 • Diverted to Miami after encountering turbulence at approximately 0756 UTC near the Dominican Republic • 26 passengersand crew injured • Illustrates difficulty in forecasting rapidly-developing cells with MOG turbulence

  6. Continental 128 (0815 UTC 3 August 2009) Cloud Top Height

  7. Motivation: Increasing International Air Travel • Total passenger traffic between the U.S.A and the world ~147.1 million in 2007 • 2010-2025, international passenger growth projected at ~4.5% / year • 331.5 million in 2025 • Suggests a greater need for oceanic aviation weather products

  8. FAA Oceanic Operations Oceanic Flight Information Regions (FIR) Plus Alaska and CONUS !

  9. Current Products for International/Oceanic Aviation • International Flight Folder on NWS Aviation Weather Center web site contains: • International SIGMETs – 4 hourly updates – graphical and text • Significant Weather (SigWx) prognostic chart – 6 hrly updates – graphical • Hurricane and tropical storm SIGMETs – 6 hrly updates – text • Infrared satellite imagery (black and white; color) – full disk updates 3 hrly

  10. Next Generation ATS Requirements • FAA Next Gen requirements for Global Airspace • Identification and forecasting of deep convection occurrence and intensity • Identification and forecasting of turbulence occurrence and intensity • In-flight display of weather hazards • Current research • Oceanic Convection Diagnosis and Nowcasting (NASA-ROSES) • Global Turbulence Decision Support System for Aviation (NASA-ROSES) • Weather Technology in the Cockpit (FAA)

  11. CTop CClass GCD Current: Convective Nowcasting Oceanic (CNO) makes 1-hr and 2-hr nowcasts of storm location using an object tracker CNO Polygons CNO-G Gridded Nowcast Future: CNO-G will produce gridded nowcasts that will more closely resemble storm structures Ocn Convection Diagnosis & Nowcasting System Convective Diagnosis Oceanic (CDO) identifies convective cells CDO Interest CDO Binary Product Greater Gulf of Mexico/Caribbean domain Hourly fx to 8 hr; 30 minute updates Global domain Hourly fx to 8 hr; 3 hourly updates

  12. Cloud Top Height Algorithm • Developed by Steve Miller, Naval Research Laboratory • Implemented at NCAR • Algorithm: • Converts longwave IR (10.8 micron) brightness temperature to cloud top pressure using a GFS model sounding • Cloud top pressure is converted to cloud top height via the standard atmosphere assumption • Strengths: • Can be calculated globally – all satellites have this channel • Day and night • Best performance with optically thick clouds like deep convection • Limitations: • Only for clouds above 15Kft • Cannot detect overshooting tops

  13. Cloud Classification Algorithm • Developed by Paul Tag, Richard Bankert, Naval Research Laboratory • Implemented at NCAR • Algorithm: • Uses all satellite channels (Terrascan or Gini formats) • Calculates feature fields on current image and compares results to a validation data set made by human expert • Does a 1-nearest neighbor best match to determine cloud type • Strengths • Excellent performance at defining cloud types • Daytime and nighttime versions of the algorithm • Daytime version performs best • Successfully tested on MTSAT and Meteosat-9 for global application • Limitations • Computationally intense, but could be tiled and stitched

  14. Global Convection Diagnosis Algorithm • Developed by Fred Mosher, Aviation Weather Center • Modified version implemented at NCAR • Algorithm: • Uses channel differencing • Brightness temperature from the longwave IR channel is subtracted from the brightness temperature of the water vapor channel • Differences near 0 indicate mature convection • Strengths: • Can be calculated globally – all satellites have these 2 channels • Limitations: • Occasionally detects cirrus

  15. Convective Diagnosis Oceanic (CDO) (Lightning) GOES-East CTOP CTOP CDO Binary Product CClass CClass GCD GCD CDO Interest Field (0-4 day, 0-3 night)

  16. IR 5 km PR CAPPI TRMMHAZARD CDO Interest TRMM Validation of the CDO Interest • Validation important to optimize and tune algorithms for best performance and to measure performance • Remote, oceanic regions are a validation challenge • Few instruments • Independent measurements best • Low earth orbit satellites provide comparison to geo-satellites • Tropical Rainfall Measuring Mission (TRMM) • VIRS • Precipitation Radar (PR) • Lightning Imaging Sensor (LIS) • Convective rainfall product T=Convective rain Z=>30 dBZ at 5km L=Lightning • Hurricane Dean 12-22 Aug 2007 • Donovan et al. (2009)

  17. Hit False Alarm Correct Negative Hit Correct Negative Example of CDO Interest Validation • Manual scoring of each storm to fill a 2x2 contingency table T=Convective rain Z=>30 dBZ at 5km L=Lightning

  18. CDO Interest Field Verification Results • Statistical performance separated by various categories • Object based • 1817 storms between 12-22 August 2007 (Hurricane Dean)

  19. CTop CClass GCD Current: Convective Nowcasting Oceanic (CNO) makes 1-hr and 2-hr nowcasts of storm location using an object tracker CNO Polygons CNO-G Gridded Nowcast Future: CNO-G will produce gridded nowcasts that will more closely resemble storm structures Ocn Convection Diagnosis & Nowcasting System Convective Diagnosis Oceanic (CDO) identifies convective cells CDO Interest CDO Binary Product Greater Gulf of Mexico/Caribbean domain Hourly fx to 8 hr; 30 minute updates Global domain Hourly fx to 8 hr; 3 hourly updates Greater Gulf of Mexico/Caribbean region

  20. CSI BIAS Convection Nowcasting Oceanic (CNO) Product CNO-Titan Nowcast • Using CDO, nowcast location of deep convection. Two extrapolation methods tested (Cai et al. 2010) • TITAN (object tracking to 6hr, with growth/decay) • Gridded Forecast (gridded to 6hr, no growth/decay) • Validation over 5 days from Aug 19-23, 2007 • Both methods show skill over Persistence • Gridded Forecast is best overall method • Implemented in greater Gulf of Mexico and global domains CNO-Gridded Nowcast

  21. Summary Statistics of CNO-Gridded Forecasts 1-8hr The black squares are statistics from Aug 19-22, 2007 What are the GFS model scores for oceanic convection??? • 30 days of data from Sep 1-30, 2009 over the Gulf of Mexico domain are used to calculate the statistics with a grid size of ~ 5 km and CDO threshold of 2.5 • The results showed here could serve as benchmark performance of extrapolation-based nowcasting techniques for oceanic convection • Similar verification for model forecasts need to be done so that a comparison of convective forecasting skills between model and extrapolation can be obtained

  22. Examples of Gridded Forecast in the Gulf of Mexico Domain 1 HR 3 HR 6 HR Issue time: 1215 UTC 2009/09/05 Valid time: 1815 UTC 2009/09/05 Issue time: 1215 UTC 2009/09/05 Valid time: 1315 UTC 2009/09/05 Issue time: 1215 UTC 2009/09/05 Valid time: 1515 UTC 2009/09/05 *White lines are CDO=2.5 verification, satellite data available every 30 min

  23. Global Convection Diagnosis • From 2 inputs (CTOP and GCD), CDO is calculated globally • GOES-E, GOES-W, Meteosat 7 and 9, MTSAT • Global Graphical Turbulence Guidance will use to locate potential convectively-induced turbulence Convective Diagnosis Oceanic Binary Product Convective Diagnosis Oceanic Interest Field

  24. Weather Technology in the Cockpit Future Positions Flight Path Current Position • Aircraft-relative display of cloud top height • Pilot and dispatcher receive a “heads up” for approaching weather • Common situational awareness • 2006: United Airlines demo on US-Aus flights • Favorable feedback from pilots • Unsolicited wx information got their attention ASCII display via ACARS thermal printer Cloud Top Height >40kft 30-39kft

  25. Acknowledgements This research is supported by NASA, primarily under Grant No. NNA07CN14A. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Aeronautics and Space Administration. Contact Information for Cathy Kessinger Email: kessinge@ucar.edu Voice: 303-497-8481

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