Modeling study of the coastal upwelling system of the Monterey Bay area during

1999 and 2000.

I. Shulman (1), J.D. Paduan (2), L. K. Rosenfeld (2),

S. R. Ramp (2), J. C. Kindle (1)

(1) Naval Research Laboratory, Stennis Space Center, MS

(2) Naval Postgraduate School, Monterey, CA

SUPPORT:

NOPP “Innovative Coastal-Ocean Observing Network (ICON)”

ONR Ocean Modeling and Prediction

ONR Biological and Chemical Oceanography

OUTLINE

•Physical Model Configuration

•Model Validation and Related Issues

•Data Assimilation

•Conclusions and Future Plans

Hierarchy of different resolution models in the Pacific

Ocean. Provides large-scale, basin-scale and small-scale view on the Monterey Bay

circulation.

Global (NLOM or NCOM)

PWC (POM or NCOM)

ICON MODEL• Grid resolution ~ 1-4 km,

30 vertical

• Open boundary conditions are derived from Pacific West Coast (PWC) NRL model (resolution ~10km).

• Atmospheric forcing from NOGAPS and COAMPS

predictions.

• Assimilation of CODAR data.

M1

M2

M3

M4

Observed and ICON model SSTsAugust 31, 1999

Pt. Sur

Santa Crus

Table 1.

ICON Model Runs in 1999 Run #

Wind

Forcing* Surface Heat

Forcing** Open Boundary

Forcing*** CODAR

Assimilation 1 NOGAPS None PWC0.0 None 2 NOGAPS MCSST PWC0.0 None 3 COAMPS None PWC0.0 None 4 COAMPS MCSST PWC0.0 None 5 COAMPS COAMPS PWC0.0 None 6 COAMPS None PWC2.1 None 7 COAMPS COAMPS PWC2.1 None 8 NOGAPS None PWC0.0 Yes **** 9 COAMPS None PWC0.0 Yes ****

ICON Model Runs in 2000 (January 1 – October 1) 10 COAMPS COAMPS PWC10.9 No 11 COAMPS COAMPS PWC10.9 Yes

* 9km resolution COAMPS used ** MCSST surface temperatures always assimilated into PWC but only assimilated in ICON model where indicated. *** PWC0.0 is forced with NOGAPS wind, PWC2.1 and PWC10.9 are forces with 27 km, operational COAMPS wind in 1999 and 2000 respectively. **** Runs 8, 9 and 11 were done with the use of several CODAR data assimilation schemes.

Impact of high-resolution wind forcing on ICON model

predictions

PWC and ICON forced with ~90km wind (NOGAPS)

ICON forced with 9km wind ( COAMPS)

PWC forced with ~ 90km wind (NOGAPS)

ICON forced with 9km wind (COAMPS)

PWC forced with 27km wind (COAMPS)

Standard Deviation of SST. 4-6/99, energy at periods > 90 d removed

0.1C

0.8CNOGAPS (91km)

COAMPS (9km)

D. Blencoe, MS thesis

The model run with COAMPS 9km wind forcing better captured the influence of the complex coastline and topography structure.

The model run with COAMPS 9km wind displayed more details and

produced stronger headland effects.

Coupling with larger-scale PWC modelComparison ADCP and model-predicted currents

at buoy M2

Magnitude of complex correlation Angular displacements

Impact of surface heat forcing on ICON model predictions.

Observed and model predicted MLDs (m)

0.1 ˚C 0.2 ˚C 0.1 ˚C 0.2 ˚C

Offshore core of the California current

California Undercurrent

California UndercurrentRAFOS floats vs ICON model currents, 300m

Conclusion

• With high-resolution atmospheric forcing the ICON model captures “the essence” but not the “details”of observed variability.

• Data Assimilation (“blending” of observations and model predictions) is needed

HIGH FREQUENCY RADAR (CODAR) DATA ASSIMILATION

IN THE MONTEREY BAY.

APPROACH

Methods of using HF radar data to provide corrections to

the model wind forcing are investigated.

Figure 4. Alongshore component of wind at the M1 mooring and the mode 1 amplitude for the radar-derived (CODAR) surface velocity fields as a scatter plot (left panel) and versus time (right panel).

Inadequate knowledge of the wind stress is probably a significant source of error in the model solutions.

Figure 6. CODAR data footprints (dots) and locations of M1 and M2 moorings

Magnitudes of complex correlation (a) and angular displacements (b) between model-

predicted currents and those observed at M2.

Map of complex-correlation magnitudes between observed currents at M2 and HF radar-derived surface currents (upper level in each panel) or

model-predicted currents at various depths.

No assim. With assim.

Map of complex-correlation magnitudes between observed currents at M1 and HF radar-derived surface currents (upper level in each panel) or

model-predicted currents at various depths.

No assim. With assim.

W M Av2 f

Us curlzUs .

Div M ICON forced with ~90km wind

(NOGAPS)

242d day

245th day

Along-shore model velocitiesSection AA

Section BB

Bioluminescence

AA BBBioluminescence maximums at 242d and 245th days are located in the frontal areas representing a strong reversal of flow direction.

FUTURE

• Use of circulation model for optimal and adaptive sampling

• Bio-optical and physical modeling

• Data Assimilation: CODAR, SSTs, glider and mooring data, estimation and modeling covariances.