NAVOCEANO Operational Ocean Modeling

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NAVOCEANO Operational Ocean Modeling

• MAST Workshop
• 21 July 2008
• Frank.Bub_at_Navy.mil 228-688-4758
• steven.w.payne_at_navy.mil 228-688-5507

Approved for Public Release
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Navy Layered Ocean Model (NLOM)

• 1/32 degree resolution
• 7 vertical layers (MLD 6 layers)
• 96-hour forecasts (30 days every Sunday)
• 200m or deeper water
• Sea Surface Temp, Salinity Height
• SSH for Global Circulation Models
• For position of fronts and eddies
• NOT VALIDATED FOR CURRENTS

1/32 deg (3.5 km / 1.9 nm)
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Global Navy Coastal Ocean Model (G-NCOM)

• POM-based
• 3D Forecasts of Temperature, Salinity,
  Currents, Elevation
• Resolution 1/8 deg
• 42 vertical layers
• Forecast to 72hr _at_ 3hr increments
• NOGAPS atmosphere forcing
• Assimilates SST / SSH / Profiles
• NCODA
• Deep water mesoscale processes
• Tides from OSU (Egbert) model
• Lateral boundary conditions for higher resolution
  nests (SWAFS / regional NCOM)
• Data available at
• http//edac.northerngulfinstitute.org/opendap_inde
  x.html

1/8 deg (14 km / 7.5 nm)
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Operational Ocean Observations

• AVHRR GAC Satellite SST
  800,000 obs/day
• 8-km resolution (NOAA 17,18 day, night, relaxed
  day retrievals)
• AVHRR LAC Satellite SST
  2,500,000 obs/day
• 2-km resolution (NOAA 17,18 day, night
  retrievals)
• GOES Satellite SST
  5,000,000 obs/day
• 12-km resolution (GOES 11,12 day, night
  retrievals)
• In Situ SST/SSS
  15,000 obs/day
• surface ship, fixed and drifting buoys, CMAN,
  TRACKOB
• Subsurface Temperature and Salinity Profiles
  1000 profiles/day
• XBTs, CTDs, Argo Floats
• fixed buoys (TAO, PIRATA), thermistor chain
  drifting buoys
• Sea Surface Height Anomaly (SSHA)
  80,000 obs/day
• altimeter (Jason, ENVISAT), CTDs, Argo Floats
• Sea Ice Concentration
  1,000,000 obs/day
• SSM/I (DMSP F13, F14, F15, F16)

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Shallow Water Analysis and Forecast System (SWAFS)

• POM-based
• 3D Forecasts
• T, S, Currents, Elevation
• Resolution varies by region (1/50 to 1/4 deg)
• 27 to 47 vertical layers
• Forecast to 48hr _at_ 1hr increments
• Assimilates data from
• Satellites (SST, SSH)
• insitu obs (XBTs, CTDs, floats, buoys)
• IHO tides

Up to 1/50 deg (2.2 km / 1.2 nm)
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Hi-Resolution Navy Coastal Ocean Model (Hi-Res
NCOM)
Hi-Res Guam SST Daily SSS

• Same structure / algorithms as GNCOM
• BCs provided by GNCOM
• FNMOC COAMPS forcing
• 3D Forecasts
• T, S, Currents, Elevation
• Resolution varies (1/36 deg)
• 41 vertical layers
• Forecast to 48 (72) hr _at_ 3 (1) hr increments
• Assimilates data from
• Satellites (SST, SSH)
• insitu obs (XBTs, CTDs, floats, buoys)
• Demonstrated in Guam area during Navy exercise
  Valiant Shield
• Plan to implement 4 regions/year, 16 total, to
  support Navy operations

3-hourly Temp _at_ 400m Watch for eastward
propagating internal tides
1/36 deg (3 km / 1.7 nm)
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Advanced Circulation Model (ADCIRC)

• 2D Barotropic ADCIRC
• Next generation finite element model
• Consortium model (NRL, Notre Dame, UNC, NOAA NOS,
  )
• Coastal currents, elevation
• Can be rapidly deployed
• Inputs winds at each node
• Fully tidal forcing
• Run on Linux or MSRC
• OPEVAL FY08
• 3D Baroclinic ADCIRC
• Coastal ASW applications
• T, S, currents, elevations
• FY10

Katrina Inundation
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Simulating Waves Nearshore (SWAN)

• Part of U. Delft DELFT3D package
• A 3RD generation stand-alone (phase-averaged)
  wave model
• Simulates waves in deep, intermediate and
  nearshore depths
• Forecasts into surf zone
• Resolutions from regional (1/12 deg) to beach
  (10 m)
• Deliver graphics, data (NetCDF properties similar
  to WAM)
• Replacing WAM domains
• Transitioned to NAVO FY06

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PC Tides

• Application of wave equation
• 2D barotropic model
• Forced by tidal stations FNMOC / local winds
• Tidal elevation currents
• Assimilates nearby tidal stations (4000 IHO
  stations)
• 2-minute bathymetry (DBDB2)
• Nest to needed resolution
• Provides a first guess - rapid implementation
  (lt24 hours)
• 2D graphics, time series, constituent table
  outputs
• Hurricane storm surge module

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NAVOCEANO Models Data-Flow Wiring
Diagram(Simplified Version)

• MSRC UNCLASSIFIED
• OCEAN MODELS
• NLOM
• NCOM
• SWAFS
• WAM
• MODAS
• PCTIDES
• ADCIRC
• SWAN
• HYCOM
• KRAKEN - BABBAGE

MSRC STORAGE ARCHIVE VINCENT

• DATA COLLECTION
• Data Sources
• External Flow
• BASTION - STREAKER

GRAPHICS
WEB SERVICES

• SATELLITE DATA PROCESSING
• SST
• Altimetry
• Color
• ADFC

• MSRC CLASSIFIED
• OCEAN MODELS
• MODAS
• SWAFS
• SWAN
• PCTIDES
• ADCIRC
• RELO NCOM
• PASCAL

PRODUCT PUSH TGS

• ROAMER (LINUX)
• Set up
• Runstream
• Monitor
• Product generation

GRAPHICS
RMA2
WQMAP
WEB SERVICES
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Hybrid Coordinate Ocean Prediction System (HYCOM)

• Next generation dynamic model
• NOPP Consortium NRL lead, U Miami, Los Alamos,
  French, NOAA/AOML, etc.
• Temperature, Salinity, Currents, Elevation
• Initial global resolution 1/12 deg (2008)
• Final resolution 1/25 deg (2011)
• 40 vertical layers
• Pressure, depth, sigma coordinates as needed
• Forecast to 120hr
• Assimilates SST / SSH / profile data using NCODA
• Global regional model replacements
• Global service to NOAA, others
• ESMF backbone
• http//hycom.rsmas.miami.edu/

NRL Stennis graphics
1/12 (9 km / 5 nm) ? 1/25 deg (3.8 km / 1.8 nm)
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HYCOM HYbrid Coordinate Ocean ModelNCODA
Navy Coupled Ocean Data Assimilation

• Deliverable
• 1/12 fully global ocean prediction system (7 km
  mid-latitude) transitioned to the Naval
  Oceanographic Office in 2008
• Progress
• 1/12 global HYCOM/NCODA running in real-time in
  the NAVOCEANO operational queues since 16 Feb
  2007
• Produces daily 5-day hindcasts up to the nowcast
  time, and up to a 7 forecast (depending on
  resource availability)
• Graphical and digital output available through
  the HYCOM consortium web pages
  http//www.hycom.org
• Validation efforts underway comparing against
  operational 1/8 global NCOM (Navy Coastal Ocean
  Model)
• Sensitivity studies to atmospheric forcing and
  model parameters to optimize model performance
  and simulation of ocean dynamics

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Global HYCOM Configuration

• Horizontal grid 1/12 equatorial resolution
• 4500 x 3298 grid points, 6.5 km spacing on
  average, 3.5 km at pole
• Mercator 79S to 47N, then Arctic dipole patch
• Vertical coordinate surfaces 32 for s2
• KPP mixed layer model
• Thermodynamic (energy loan) sea-ice model
  switching to CICE
• Surface forcing FNMOC NOGAPS 0.5 wind stress,
  wind speed, thermal forcing, and NOGAPS 1.0
  precipitation
• Monthly river runoff (986 rivers)
• Initialized from January climatology (GDEM3) T
  and S, then SSS relaxation from PHC 3.0
• No subsurface relaxation to climatology

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1/12? Global HYCOM Capabilities

• Depict location of mesoscale features such as
  oceanic eddies and meandering currents and fronts
• Sea surface height forecast skill over
  persistence and climatology
• Provide accurate 3D ocean temperature, salinity
  and current structure
• Provide boundary conditions for regional and
  coastal models
• Nested model can be of similar (e.g. NCOM s/z)
  or dissimilar design (e.g. ADCIRC finite
  element)
• Provide ice concentration and thickness along
  with a capability to predict areas of lead
  opening and closings

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Navy Coupled Ocean Data Assimilation (NCODA)
Ocean Obs
Sequential Incremental Update Cycle
Analysis-Forecast-Analysis
Ocean QC
SST GAC/LAC MCSST, GOES, Ship, Buoy Profile
XBT, CTD, PALACE Float, Fixed Buoy, Drifting Buoy
Altimeter SSHA SSM/I Sea Ice
3D MVOI
Increments
HYCOM Model
First Guess
Forecast Fields Prediction Errors
MVOI - simultaneous analysis 6 ocean variables
temperature, salinity, geopotential, layer
pressure, velocity (u,v)
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HYCOM/NCODA Runstream
Valid nowcast time
00Z
00Z
00Z
00Z
00Z
00Z
00Z
00Z
00Z
00Z
-120
-96
-72
-48
-24
0
Tau
24
48
72
96

• Perform first NCODA analysis centered on tau
  -126, i.e. 18Z
• Run HYCOM for 24 hrs using incremental updating (
  ) over the first 6 hrs
• Repeat steps 1) and 2) until the nowcast time
• Run HYCOM in forecast mode out to tau 120

• Approximate run times (using 379 IBM Power 5
  processors)
• Six NCODA analyses 0.9 hrs/analysis 5.4 hrs
• Five HYCOM hindcast days _at_ 150 sec ?t 1.1
  hrs/day 5.5 hrs
• Four HYCOM forecast days _at_ 150 sec ?t 1.1
  hrs/day 4.4 hrs
• Total 15.3 hrs

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Available altimeter data23 January 2008
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NCODA Observation Locations
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Validation Tasks

• Large scale circulation features
• Determine correct placement of large scale
  features
• Sea Surface Height (SSH) variability / Eddy
  Kinetic Energy (EKE)
• Determine if the system has a realistic level and
  distribution of energy at depths
• Mixed layer depth (MLD) / sonic layer depth (SLD)
  / deep sound channel (DSC) / below layer gradient
  (BLG)
• Compare simulated vs. observed for
  non-assimilated ARGO floats
• Vertical profiles of TS
• Quantitative comparison of simulated vs. observed
  for non-assimilated ARGO floats
• Sea surface temperature
• Evaluate whether the models are producing
  acceptable nowcasts and forecasts of sea surface
  temperature
• Coastal sea level
• Assess the models ability to represent observed
  sea surface heights

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Data Assimilation in Global HYCOMGulf Stream and
Kuroshio SSH with SST-based frontal analysis
overlaid
24 January 2008
2 February 2008
Frontal analysis lt 4 days old white, analysis
4 days old black
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1/12º Global HYCOMSSH and surface drifters in
the Kuroshio Region
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1/12º Global HYCOMSSH and surface drifters in
the Kuroshio Extension
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SSH Variability Evaluation
Measure of the mesoscale eddy field
Area avg. 7.8 cm
Oct 92 May 07 SSH variability based on T/P,
ERS-1 and ERS-2 altimeters (from Collecte,
Localisation, Satellites (CLS))
Area avg. 8.4 cm
SSH variability over 2004-2006 from a 1/12
global HYCOM/NCODA hindcast simulation
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MLD Error Analysis
JJ/2007 MLD Median Bias Error (MdBE) model vs.
6K assim. profiles
HYCOM/NCODA MdBE -5 m, RMSE 53 m
gNCOM 02f MdBE -4 m, RMSE 62 m
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Temperature vs. Depth Error Analysis
HYCOM Cooper-Haines (black) vs. HYCOM using MODAS
synthetics (red) vs. NCOM-03a (blue)
Mean error (C)
RMSE (C)
Based on 8400 unassimilated profiles over global
ocean for the period Jun-Jul 2007
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Sea Surface Temperature Evaluation
Data type MCSST, 19,000,000 observations
Data type Drifting buoys, 520,000 observations
Based on thirty 4-day / 3-day forecasts from
HYCOM / NCOM over the period June-July 2007
Limited between 45S 45N
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Forecast Verification Statistics from 1/12?
Global HYCOM
1.0
0.9
World Ocean
Gulf Stream
Persian Gulf
0.8
0.7
Median SSH anomaly correlation
1.0
Equatorial Pacific
0.9
Kuroshio
Taiwan
0.8
0.7
0.6
0
10
20
30
0
10
20
30
0
10
20
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Forecast length (days)
Atmospheric analysis forcing
operational forcing persistence
? 16 Forecasts included in statistics
Operational forcing reverts toward climatology at
the end of the atmospheric forecast.
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HYCOM Future Plans

• Increase to 1/25 resolution globally (3-4 km
  mid-latitude)
• R D starting in FY09, transition in FY12
• Internal/external tides
• Optimal resolution for basin-scale
• Direct boundary conditions for coastal models
• Eliminates need for regional models
• Zero depth boundaries
• Wetting/drying capability
• NAVO wants the above capabilities in order to
  support customer needs
• ONR plans to support this work with a 5-year
  follow-on NOPP project (FY09-FY13)
• We have proposed a follow-on HPC Challenge
  project (FY09-FY11) to support this work

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HYCOM Future Plans (Continued)

• Tides in HYCOM (with Brian Arbic, U. Texas)
• State-of-the-art scientific foundation
• Initial testing in 1/12 global HYCOM with
  internal/external tides under a HPC CAP project,
  major testing in follow-on NOPP project
• 1st eddy-resolving global ocean circulation model
  with tides
• Planned for operational use in 1/25 global HYCOM

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Snapshot of Steric SSH Amplitude Due to the M2
Internal Tide
5 cm
0
Demonstration of internal tidal signature at the
surface from a 1-month simulation using
32-layer, 1/12 global HYCOM with wind forcing