update on hydrodynamic model comparisons

Update on hydrodynamic model comparisons

Marjy Friedrichs and Carl FriedrichsAaron Bever (post-doc)Leslie Bland (summer undergraduate student)

Methods: Target diagrams (Jolliff et al., 2009)

1

1

-1

-1 Unbiased RMSD

Bias

Total RMSD2 = Bias2 + unbiased RMSD2

mean seasonalvariability

x > 0overestimates

variability

y > 0: overestimates

mean

Methods: Target diagrams (Jolliff et al., 2009)

1

1

-1

-1 Unbiased RMSD

Bias

Total RMSD2 = Bias2 + unbiased RMSD2

mean variability

x > 0overestimates

variability

y > 0: overestimates

mean

Methods: Target diagrams (Jolliff et al., 2009)

1

1

-1

-1 Unbiased RMSD/stdev(obs)

Bias/stdev(obs)

Normalization by standard deviation of observations

outer circle: Model-data misfit = variability in data

x > 0overestimates

variability

y > 0: overestimates

mean

Methods: Target diagrams (Jolliff et al., 2009)

1

1

-1

-1 Unbiased RMSD/stdev(obs)

Bias/stdev(obs)

Normalization by standard deviation of observations

outer circle: Model-data misfit = variability in data

x > 0overestimates

variability

y > 0: overestimates

mean

Methods: Target diagrams (Jolliff et al., 2009)

1

1

-1

-1 Unbiased RMSD/stdev(obs)

Bias/stdev(obs)

Normalization by standard deviation of observations

outer circle: Model-data misfit = variability in data

x > 0overestimates

variability

y > 0: overestimates

mean

model does worse than the mean of the data

Model simulationsOriginal 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)

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

New model comparisons (Fall ‘10)Best match over ±12 hour time

windowAdditional variables:

dS/dz at max dS/dz z of max dS/dz S at max dS/dz

New ‘consistent forcing’ simulations

New model comparisons (Fall ‘10)Best match over ±12 hour time

windowAdditional variables:

dS/dz at max dS/dz z of max dS/dz S at max dS/dz

New ‘consistent forcing’ simulations

= inst match = best

match(over 24h)

SurfaceSalinity

New model comparisons (Fall ‘10)Best match over ±12 hour time

windowAdditional variables:

dS/dz at max dS/dz z of max dS/dz S at max dS/dz

New ‘consistent forcing’ simulations

Salinity (psu)

Stratification=

max dS/dz

depth of max dS/dz

Salinity (psu)

Salinity at max dS/dz

Salinity (psu)

New model comparisons (Fall ‘10)Best match over ±12 hour time

windowAdditional variables:

dS/dz at max dS/dz z of max dS/dz S at max dS/dz

New ‘consistent forcing’ simulations

Surface Salinity

EFDC CBOFS2

New forcing: Slight improvement in CBOFS2 resultsSlight degradation in EFDC results

Red = First runsBlack = New or consistent forcing runs.The EFDC results here are without showing the far outliers.

= old results

= new results

max dS/dz

old forcing

new forcing

Salinity (psu)

max dS/dz

newforcing

Salinity (psu)

Salinity (psu)

depth ofmax dS/dz

old forcing

new forcing

Salinity (psu)Salinity (psu)

depth of max dS/dz

newforcing

Salinity (psu)

Salinity (psu)

Salinity atmax dS/dz

old forcing

new forcing

Salinity (psu)

Salinity (psu)

Salinity atmax dS/dz

newforcing

Salinity (psu)

Salinity (psu)

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