Overview of T-PARC Falcon operations and ECMWF data denial experiments

1. Overview of T-PARC Falcon operations and ECMWF data denial experiments Martin Weissmann, Florian Harnisch, Stephan Rahm, Martin Wirth Institut für Physik der Atmosphäre, DLR Oberpfaffenhofen, Germany Pat Harr, Naval Postgraduate School, USA Tetsuo Nakazawa and Kotaro Bessho, MRI-JMA, Japan Sarah Jones and Doris Anwender, Universität Karlsruhe/Forschungszentrum Karlsruhe, Germany David Parsons, World Meteorological Organization Hee-Sang Lee, National Institute for Meteorologial Research, Korea Ron McTaggert-Cowan, Environment Canada Carla Cardinali, ECMWF, United Kingdom

2. Overview of Falcon operations • Falcon objectives: • typhoon targeting • extratropical transition of tropical cylcones • lidar observations for NWP • Falcon funding institutions • DLR (Germany), NSF (USA), JMA (Japan) Forschungszentrum Karlsruhe (Germany), NIMR (Korea) • Environment Canada, EUCOS • Falcon operations • 23 August - 3 October 2008 in Japan • 25 research flights • 93 flight hours in total • hosted by US Navy @ NAF Atsugi (near Tokyo) Falcon flights

3. Japan S-Korea Japan Okinawa Sinlaku Highlight 1: Water vapour lidar observations in typhoon environment (11 Sept. 2008) IR Satellite Image 09/11/08 2030 LT contentrations of 0.01-15 g/kg measured by new worldwide unique 4-wavelength DIAL 16W IR Satellite Image 09/11/08 1830 LT source of satellite images: https://www.fnmoc.navy.mil/tcweb/cgi-bin/tc_home.cgi/

4. Highlight 2: Wind lidar observations A-TReC 2003 A-TReC 2003 30 Sept 2008: flight into jet for ET objectives A-TReC 2003: ~ 3% reduction of mean forecast error over Europe by lidar (Weissmann and Cardinali, QJ 2007) GOAL: investigate the general validity of these results with larger data set (60 flight hours during T-PARC) T-PARC: twice the amount of A-TReC lidar data

5. Highlight 3: Joint mission for typhoon targeting (TY center, surrounding and sensitive area) SV Japan China ETKF Concept for ideal mission: joint mission on 11 September WC-130 observations in typhoon center (green) DOTSTAR observations in typhoon surrounding (blue) Falcon obs. in sensitive area highlighted by e.g. SV, ETKF (red) sensitivity experiments by Florian Harnisch --> poster in the afternoon ECMWF experiments for center, surrounding, sensitive area

6. Tracks of typhoons Sinlaku and Jangmi with flight times

7. Influence of T-PARC observations an ECMWF typhoon track prediction significant small sample Sinlaku Jangmi gray: no dropsondes green: operational dropsonde data (two different model versions) magenta: with time-corrected dropsondes on average, forecast error reduction with corrected dropsondes on average, operational setup has similar errors as without dropsondes improvements at a high level of forecast skill, no real forecast busts

8. from Jim Doyle, Navy Research Lab., USA Influence of T-PARC observations an ECMWF typhoon track prediction significant small sample Sinlaku Jangmi gray: no dropsondes green: operational dropsonde data (two different model versions) magenta: with time-corrected dropsondes on average, forecast error reduction with corrected dropsondes on average, operational setup has similar errors as without dropsondes improvements at a high level of forecast skill, no real forecast busts

9. Examples of improving cases uncertainties of recurvature point --> improvement with dropsondes largest improvement with DOTSTAR dropsondes, degradation with WC-130 observations at 2008091000 (for details see poster by F. Harnisch in the afternoon)

10. Examples of neutral and slightly deteriorating cases - very good forecast without observations • remaining errors are supposedly rather connected to problems with land interaction • than initial condition errors (for details see poster by F. Harnisch in the afternoon)

11. Dropsonde observation statistics for WC-130 flight through typhoon center • Dropsondes within the typhoon are successfully assimilated in the ECMW model, but only a relatively small part of the information can be used with current DA systems due to large differences to the model first guess field • Potential for further improvements through flow dependant covariance matrix, e.g. ensemble 4D-Var • Center observations led to significant analysis differences, mainly typhoon intensification, but relatively little forecast improvements

12. T-PARC data coverage @ ECMWF ET recurvature driftsondes formation Period: 2008090900 - 2008100112

13. Influence on mid-latitude forecast error Z 500 hPa Pacific: 30-65N, 155E - 130W Z 500 hPa northern hemisphere 20-90N reduction of mid-range forecast error over the Pacific and long range northern hemisphere forecast error

14. Influence on mid-latitude forecast error (uncycled) Z 500 hPa Pacific: 30-65N, 155E - 130W no improvement without "cycling", i.e. when the analysis uses the first-guess from the control run

15. Conclusions (preliminary results) • on average, improved typhoon track prediction with additional dropsondes • improvements in particular at early typhoon stages before recurvature • largest improvements through observations in the surrounding of the storm (DOTSTAR strategy) rather than in the typhoon center or sensitive areas indicated by singular vectors or ETKF (see poster) • timing errors in operational dropsonde data set at ECMWF, corrected for the future and to my knowledge no other NWP center is affected • in mid-latitudes, improved mid-range forecast over the Pacific and long range forecast on the northern hemisphere • nearly no improvement without "cycling", i.e. when the analysis uses the first-guess from the control run • improvements are moderate, ECMWF forecasts without dropsondes are already relatively accurate • studies to investigate the influence of airborne lidar observations will follow Thanks to: - all people involved in T-PARC - Milan Dragosavac, Ioannis Mallas and all others at ECMWF involved