Update on hydrodynamic model comparisons

1. Update on hydrodynamic model comparisons Marjy Friedrichs and Carl Friedrichs Aaron Bever (post-doc) Leslie Bland (summer undergraduate student)

2. Methods: Target diagrams (Jolliff et al., 2009) Total RMSD2= Bias2+ unbiased RMSD2 mean seasonal variability Bias y> 0: overestimates mean 1 Unbiased RMSD 1 -1 x > 0 overestimates variability -1

3. Methods: Target diagrams (Jolliff et al., 2009) Total RMSD2= Bias2+ unbiased RMSD2 mean variability Bias y> 0: overestimates mean 1 Unbiased RMSD 1 -1 x > 0 overestimates variability -1

4. Methods: Target diagrams (Jolliff et al., 2009) Normalization by standard deviation of observations Bias/stdev(obs) y> 0: overestimates mean 1 outer circle: Model-data misfit = variability in data Unbiased RMSD/stdev(obs) 1 -1 x > 0 overestimates variability -1

5. Methods: Target diagrams (Jolliff et al., 2009) Normalization by standard deviation of observations Bias/stdev(obs) y> 0: overestimates mean 1 outer circle: Model-data misfit = variability in data Unbiased RMSD/stdev(obs) 1 -1 x > 0 overestimates variability -1

6. Methods: Target diagrams (Jolliff et al., 2009) Normalization by standard deviation of observations Bias/stdev(obs) y> 0: overestimates mean 1 outer circle: Model-data misfit = variability in data Unbiased RMSD/stdev(obs) 1 -1 model does worse than the mean of the data x > 0 overestimates variability -1

7. Model simulations • Original simulations (summer ‘10) • CH3D (P. Wang) • EFDC (J. Shen) • ChesROMS (W. Long) • CBOFS2 (L. Lanerolle) • New ‘consistent forcing’ simulations (this week!) • EFDC (J. Shen) • CBOFS2 (L. Lanerolle) • UMCES ROMS (Y. Li)

8. Preliminary model comparisons (Summer ‘10) • Initially examined salinity at the halocline (max dS/dz) as a function of bathymetric error, latitude, salinity, oxygen, bottom depth Conclusion: For all four models, model skill (total RMSD) is primarily a function of mean salinity and/or latitude

9. New model comparisons (Fall ‘10) • Best match over ±12 hour time window • Additional variables: dS/dzat max dS/dz z of max dS/dz S at max dS/dz • New ‘consistent forcing’ simulations

10. New model comparisons (Fall ‘10) • Best match over ±12 hour time window • Additional variables: dS/dzat max dS/dz z of max dS/dz S at max dS/dz • New ‘consistent forcing’ simulations

11. Surface Salinity = inst match = best match (over 24h)

12. New model comparisons (Fall ‘10) • Best match over ±12 hour time window • Additional variables: dS/dzat max dS/dz z of max dS/dz S at max dS/dz • New ‘consistent forcing’ simulations

13. Salinity (psu) Stratification= max dS/dz

14. Salinity (psu) depth of max dS/dz

15. Salinity (psu) Salinity at max dS/dz

16. New model comparisons (Fall ‘10) • Best match over ±12 hour time window • Additional variables: dS/dzat max dS/dz z of max dS/dz S at max dS/dz • New ‘consistent forcing’ simulations

17. Surface Salinity Red = First runs Black = New or consistent forcing runs. The EFDC results here are without showing the far outliers. CBOFS2 EFDC = old results = new results New forcing: Slight improvement in CBOFS2 results Slight degradation in EFDC results

18. max dS/dz old forcing Salinity (psu) new forcing

19. Salinity (psu) max dS/dz new forcing Salinity (psu)

20. depth of max dS/dz old forcing Salinity (psu) Salinity (psu) new forcing

21. Salinity (psu) depth of max dS/dz new forcing Salinity (psu)

22. Salinity at max dS/dz old forcing Salinity (psu) Salinity (psu) new forcing

23. Salinity (psu) Salinity at max dS/dz new forcing Salinity (psu)

24. Next steps for hydrodynamic comparisons? • Why does CH3D produce superior stratification? • Vertical grid structure? C&D canal? Bathymetry? • other? • Next model runs • Atmospheric forcing? • Boundary conditions on shelf? • Additional metrics