Experiments with Experiments with Monthly Monthly Satellite Ocean Color Fields Satellite Ocean Color Fields in a NCEP Operational Ocean Forecast in a NCEP Operational Ocean Forecast System System PI: Eric Bayler, NESDIS/STAR PI: Eric Bayler, NESDIS/STAR Co-I: David Behringer, Co-I: David Behringer, NWS/NCEP/EMC/GCWMB NWS/NCEP/EMC/GCWMB Co-I: Avichal Mehra, NWS/NCEP/EMC/MMAB Co-I: Avichal Mehra, NWS/NCEP/EMC/MMAB Sudhir Nadiga, NWS/NCEP/EMC – IMSG Sudhir Nadiga, NWS/NCEP/EMC – IMSG
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Experiments with Monthly Satellite Ocean Color Fields in a NCEP Operational Ocean Forecast System PI: Eric Bayler, NESDIS/STAR Co-I: David Behringer, NWS/NCEP/EMC/GCWMB.
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Experiments withExperiments withMonthly Monthly Satellite Ocean Color FieldsSatellite Ocean Color Fields
in a NCEP Operational Ocean Forecast Systemin a NCEP Operational Ocean Forecast System
PI: Eric Bayler, NESDIS/STARPI: Eric Bayler, NESDIS/STAR
Co-I: David Behringer, NWS/NCEP/EMC/GCWMBCo-I: David Behringer, NWS/NCEP/EMC/GCWMB
Annual chlorophyll cycle, no subsurface data assimilation
12-year model run: cyclical chlorophyll, sequential atmospheric forcing (1998-2009)
Experiment 2 (Exp2): SeaWiFS monthly mean chlorophyll (1998 – 2010)
Sequential monthly-mean chlorophyll no subsurface data assimilation
12-year model run: sequential chlorophyll and atmospheric forcing (1998-2009)5
Environmental State ReferenceEnvironmental State Reference
Climate Forecast System Reanalysis (CFSR) Reanalysis defines the mean states of the atmosphere, ocean, land surface and
sea ice Global, high-resolution, coupled atmosphere-ocean-land surface-sea ice model
system provides the best estimate of the state of these coupled domains over the period 1979 – 2009
Continually assimilated the best possible observation data Hourly time resolution and 0.5° horizontal resolution
Produced using the MOM model, the same model used for the control and experiment cases
Employs control case chlorophyll climatology; however, the reanalysis continually assimilates the best available observations (vertical profiles of temperature, salinity, satellite altimeter data, etc.), largely correcting for the influences of chlorophyll
Saha, S., et al., 2010, “The NCEP Climate Forecast System Reanalysis,” Bull. Amer. Meteor. Soc., 91, 1015-1057.
CFSR atmosphere forcing used for the control case and both experiments
Results referenced to CFSR ocean state values
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Analysis DefinitionsAnalysis Definitions Anomaly:
Difference from designated reference (specified monthly-mean annual cycle) Index (i) represents month of data record, e.g. (i = 1) = Jan 1998
Root Mean Square Error (RMSE) RMSE includes:
Differences in monthly-mean annual cycles Differences in anomalies
Index (i) represents month of data record; e.g. (i = 1) = Jan 1998
Normalized RMSE difference RMSE comparison of specified cases with respect to a common reference Expressed in terms of percentage of the Control’s RMSE with respect to the common
reference
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Control Case: Limited Ocean Color Climatology
Upper-ocean temperature variability
Pacific “Cold Tongue”(2S – 2N, 120W)
Temperature (C)
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Control Case: Limited Ocean Color Climatology
Seasonal and interannual anomalies
Temperature (C)
* Anomalies with respect to Control case mean-monthly cycle 9
Pacific “Cold Tongue”(2S – 2N, 120W)
Control Case: Limited Ocean Color Climatology
Ocean Temperature RMSE (CFSR reference)
Temperature (C)
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Pacific “Cold Tongue”(2S – 2N, 120W)
Exp2: Sequential Monthly-mean Ocean ColorOcean Temperature RMSE (CFSR reference)
Temperature (C)
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Pacific “Cold Tongue”(2S – 2N, 120W)
Exp2 vs Control:Ocean Temperature RMSE (CFSR reference)
Pacific “Cold Tongue” (2S – 2N, 120W)
RMSE (°C)
Near-surface improvement of order 0.2C, ~ 10%
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Control Case: Limited Ocean Color Climatology
Upper-ocean temperature variability
Temperature (C)
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Pacific “Warm Pool” (2S – 2N, 165E)
Temperature (C)
Control Case: Limited Ocean Color Climatology
Seasonal and interannual anomalies
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Pacific “Warm Pool” (2S – 2N, 165E)
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Temperature (C)
Control Case: Limited Ocean Color Climatology
Ocean Temperature RMSE (CFSR reference)
Pacific “Warm Pool” (2S – 2N, 165E)
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Temperature (C)
Exp2: Sequential Monthly-mean Ocean ColorOcean Temperature (CFSR reference)
Pacific “Warm Pool” (2S – 2N, 165E)
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Exp2 vs Control:Ocean Temperature RMSE (CFSR reference)
Pacific “Warm Pool” (2S – 2N, 165E)
RMSE (°C)
Minor near-surface improvement
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Near-surface Temperature RMSEControl Case (CFSR reference)
Equatorial Zonal Cross-section (2S – 2N)
Temperature (C)
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Near-surface Temperature RMSEExp1 (CFSR reference)
Equatorial Zonal Cross-section (2S – 2N)
Temperature (C)
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Temperature (C)
Equatorial Zonal Cross-section (2S – 2N)
Near-surface Temperature RMSEExp2 (CFSR reference)
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Equatorial Zonal Cross-section (2S – 2N)
Temperature (C)
Near-surface Temperature RMSEExp1 – Control: Impact magnitude of extended ocean color
climatology
0.05
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Equatorial Zonal Cross-section (2S – 2N)
Temperature (C)
Near-surface Temperature RMSEExp2 – Exp1: Additional impact magnitude from sequential ocean
color data
0.05
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Equatorial Zonal Cross-section (2S – 2N)
Temperature (C)
Near-surface Temperature RMSEExp2 – Control: Net impact magnitude from sequential ocean
color data
0.05
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Equatorial Zonal Cross-section (2S – 2N)
Temperature (C)
Near-surface Temperature RMSE Differences:Extended Ocean Color Climatology
RMSE (Exp1) – RMSE (Control): CFSR reference
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Equatorial Zonal Cross-section (2S – 2N)
Temperature (C)
Near-surface Temperature RMSE Differences:Sequential Ocean Color Data
RMSE (Exp2) – RMSE (Exp1): CFSR reference
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Equatorial Zonal Cross-section (2S – 2N)
Temperature (C)
Near-surface Temperature RMSE Differences:Net = Extended Climatology “+” Sequential Data
RMSE (Exp2) – RMSE (Control): CFSR reference
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Equatorial Zonal Cross-section (2S – 2N)
Percent
Normalized Near-surface Temperature RMSE Differences Extended Ocean Color Climatology
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Equatorial Zonal Cross-section (2S – 2N)
Percent
Normalized Near-surface Temperature RMSE Differences
Sequential Ocean Color Data
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Equatorial Zonal Cross-section (2S – 2N)
Percent
Normalized Near-surface Temperature RMSE Differences
Air-sea heat flux impact important to fully coupled modeling (GODAS/CFS)
SummarySummary Chlorophyll:
Simulations with monthly SeaWiFS ocean chlorophyll data reduce subsurface temperature errors. Most changes in temperature are found just above the seasonal thermocline (20C isotherm)
Sea-Surface Height (SSH): Reductions of SSH errors in the equatorial cold tongue region and north of the
equator are in the 5-10% range
Ocean Heat Content (OHC): Reductions of ocean heat content errors south of the equator and in the cold tongue
region are in the 1-10% range
Currently constrained at surface. When fully coupled (GODAS/CFS), differences will influence air-sea heat fluxes.
NEXT: Comparisons of model output with real data for validation; (in situ vertical profiles of
temperature, salinity, velocity) from Pacific/Atlantic/Indian Ocean arrays and satellite altimetry
Near-real-time ocean color assimilation
Extend study to assess ocean color assimilation impact on the operational results for NOAA’s Real-Time Ocean Forecast System (RTOFS), based on the HYCOM model
Unify NOAA’s ocean color data assimilation methodology for the operational models (GODAS, RTOFS)