1. Slide 1The Wave Model - Last part Validation of wind & wave analysis using satellite & buoy. Altimeters onboard ERS-1/2, ENVISAT and Jason Quality is monitored daily. Monthly collocation plots SD 0.5 0.3 m for waves (recent SI 12-15%) SD 2.0 1.2 m/s for wind (recent SI 16-18%) Wave Buoys (and other in-situ instruments) Monthly collocation plots SD 0.85 0.45 m for waves (recent SI 16-20%) SD 2.6 1.2 m/s for wind (recent SI 16-21%)

2. Slide 2The Wave Model - Last part WAM first-guess wave height against ENVISAT Altimeter measurements (June 2003 – May 2004)

3. Slide 3The Wave Model - Last part Global wave height RMSE between ERS-2 Altimeter and WAM FG (thin navy line is 5-day running mean ….. thick red line is 30-day running mean)

4. Slide 4The Wave Model - Last part Analysed wave height and periods against buoy measurements for February to April 2002 2 4 6 8 10 12 14 H S (m) model 02468101214 H S (m) buoy 0 HS ENTRIES: 1 - 3 3 - 8 8 - 22 22 - 62 62 - 173 173 - 482 482 - 1350 02468101214161820 Peak Period Tp (sec.) buoy 0 2 4 6 8 10 12 14 16 18 20 Peak Period Tp (sec.) model TP ENTRIES: 1 - 3 3 - 6 6 - 14 14 - 33 33 - 79 79 - 188 188 - 450 SYMMETRIC SLOPE = 0.932 CORR COEF = 0.956 SI = 0.175 RMSE = 0.438 BIAS = -0.150 LSQ FIT: SLOPE = 0.879 INTR = 0.134 BUOY MEAN = 2.354 STDEV = 1.389 MODEL MEAN = 2.204 STDEV = 1.278 ENTRIES = 29470 SYMMETRIC SLOPE = 1.008 CORR COEF = 0.801 SI = 0.190 RMSE = 1.746 BIAS = 0.072 LSQ FIT: SLOPE = 0.813 INTR = 1.785 BUOY MEAN = 9.160 STDEV = 2.743 MODEL MEAN = 9.232 STDEV = 2.784 ENTRIES = 17212 02468101214 Mean Period Tz (sec.) buoy 0 2 4 6 8 10 12 14 Mean Period Tz (sec.) model TZ ENTRIES: 1 - 3 3 - 6 6 - 12 12 - 26 26 - 59 59 - 133 133 - 300 SYMMETRIC SLOPE = 0.985 CORR COEF = 0.931 SI = 0.105 RMSE = 0.779 BIAS = -0.149 LSQ FIT: SLOPE = 0.989 INTR = -0.069 BUOY MEAN = 7.306 STDEV = 1.979 MODEL MEAN = 7.157 STDEV = 2.102 ENTRIES = 6105 Wave height Peak periodMean period

5. Slide 5The Wave Model - Last part Global wave height RMSE between buoys and WAM analysis

6. Slide 6The Wave Model - Last part Quality of wave forecast Compare forecast with verifying analysis. Forecast error, standard deviation of error ( ), persistence. Period: three months (January-March 1995). Tropics is better predictable because of swell: Daily errors for July-September 1994 Note the start of Autumn. New: 1. Anomaly correlation 2. Verification of forecast against buoy data.

7. Slide 7The Wave Model - Last part Significant wave height anomaly correlation and st. deviation of error over 365 days for years 1997-2004 Northern Hemisphere (NH)

8. Slide 8The Wave Model - Last part Significant wave height anomaly correlation and st. deviation of error over 365 days for years 1997-2004 Tropics

9. Slide 9The Wave Model - Last part Significant wave height anomaly correlation and st. deviation of error over 365 days for years 1997-2004 Southern Hemisphere (SH)

10. Slide 10The Wave Model - Last part RMSE of * significant wave height, * 10m wind speed and * peak wave period of different models as compared to buoy measurements for February to April 2005

11. Slide 11The Wave Model - Last part 3. Benefits for Atmospheric Modelling 3.1. Use as Diagnostic Tool Discovered inconsistency between wind speed and stress and resolved it. Over-activity of atmospheric model during the forecast: mean forecast error versus time.

12. Slide 12The Wave Model - Last part 3.2. Coupled Wind-Wave Modelling Coupling scheme: Impact on depression (Doyle). Impact on climate [extra tropic]. Impact on tropical wind field ocean circulation. Impact on weather forecasting. ATM WAM t u 10 t u 10 time

13. Slide 13The Wave Model - Last part WAM – IFS Interface A t m o s p h e r i c M o d e l qTP air z i / L (U 10,V ) W a v e M o d e l

14. Slide 14The Wave Model - Last part Simulated sea-level pressure for uncoupled and coupled simulations for the 60 h time uncoupledcoupled 956.4 mb963.0 mb U lml > 25 m/s 1000 km

15. Slide 15The Wave Model - Last part Scores of FC 1000 and 500 mb geopotential for SH (28 cases in ~ December 1997) coupled uncoupled

16. Slide 16The Wave Model - Last part Standard deviation of error and systematic error of forecast wave height for Tropics (74 cases: 16 April until 28 June 1998). coupled

17. Slide 17The Wave Model - Last part Global RMS difference between ECMWF and ERS-2 scatterometer winds (8 June – 14 July 1998) coupling ~20 cm/s (~10%) reduction

18. Slide 18The Wave Model - Last part Change from 12 to 24 directional bins: Scores of 500 mb geopotential for NH and SH (last 24 days in August 2000)