U.S. GODAE: Global Ocean
Prediction with the Hybrid
Coordinate Ocean Model
(HYCOM)
Community Effort: NRL, U. of Miami, Los Alamos,
NOAA/NCEP, NOAA/AOML, NOAA/PMEL, PSI, FNMOC,
NAVOCEANO, SHOM, LEGI, OPeNDAP, UNC, Rutgers,
USF, Fugro-GEOS, Orbimage, Shell, ExxonMobil
Presented by Harley Hurlburt, NRL Stennis, USA
International GODAE Steering Team Meeting X
Met Office UK
Exeter, UK
14-16 Nov 2005
Present U.S. Navy Operational Capabilities Related to GODAE
Viewable on the web
http://www.ocean.nrlssc.navy.mil/global_nlom
http://www.fnmoc.navy.mil/PUBLIC
http://www.navo.navy.mil
Operational Global Ocean Product
~1/2° 2D MVOI SST Analysis
1
Inputs
Run by
IR + in situ
FNMOC
1/8 MODAS SST Analysis
2
IR
NAVO
1/4 MODAS SSH Analysis
2
ENVISAT+GFO+JASON-1
NAVO
ENVISAT+GFO+JASON-1
SST
FNMOC winds+thermal
NAVO
1/16 global NLOM nowcast/forecast
system 2
T239 or ~1/2 for atmospheric model boundary condition (on GODAE server)
2 Provide subsurface temperature
 Real-time altimetry via NAVO Altimeter Data Fusion Center (ADFC)
 NLOM: NRL Layered Ocean Model
 GODAE: Global Ocean Data Assimilation Experiment
 FNMOC operates a GODAE data server with data and products
from a variety of sources, including real-time altimetry from the NAVO ADFC
1
U.S. Navy Future Operational Transitions Related to GODAE
Participants: FNMOC, NAVO, NRL, ONR, Univ, Contractors
Global Product
Mid-Lat
Resolution
Vert.
Coord.
1/8 NCOM 1
15 km
/z
1/32 NLOM 2
3.5 km
Layered
1/12 HYCOM
7 km
1/4 HYCOM
3
1/25 HYCOM
Inputs
Run By
Target
Date
NAVO
2005
SSH, SST,
NAVO
2005
//z
hydro, FNMOC
NAVO
2007
20 km
//z
NOGAPS
FNMOC
2009
3.5 km
//z
atmospheric
NAVO
2011
Semi-operational Product 4
forcing
1/12 Atl. HYCOM 5
7 km
//z
NAVO
2006
1/12 Pac. HYCOM
7 km
//z
NAVO
2006
3.2 km
//z
NAVO
2006
1/25 Black Sea HYCOM
High vertical resolution for mixed layer prediction. Assimilates SSH from NLOM.
Running in real-time, see http://www.ocean.nrlssc.navy.mil/global_ncom
2 Running in real-time, see http://www.ocean.nrlssc.navy.mil/global_nlom
3 For coupled ocean-atmosphere prediction.
4 To give NAVO/Navy experience with HYCOM without official operational status;
to be replaced by global HYCOM including the 1/25 Black Sea HYCOM
5 Under the National Ocean Partnership Program (NOPP), 1/12 Atlantic HYCOM
demo is already running in near real-time. Includes the Mediterranean Sea.
Results at http://hycom.rsmas.miami.edu/ocean_prediction.html (80Tb LAS server soon)
1
User Interest in Real-time Global Ocean Products
NRL Oceanography Division Web Site Hit Statistics during 2004
18,467,717
Avg hits/day
# hits used in country breakdown
50,458
18,289,089
# countries with  1000 hits
67
# countries with  100 hits
120
Total number of countries
182
Includes the following real-time global
Ocean products and other results
Altimeter data
MODAS SSH & SST analyses
Ocean prediction systems
1/16 global NLOM
1/8 global NCOM
1/12 Atlantic HYCOM
Top 25 Countries and # Hits
Total # hits
United States
Japan
China
Taiwan
Germany
Great Britain
Spain
Canada
Vietnam
New Zealand
South Korea
Greece
France
Australia
Russia
Italy
Peru
India
Mexico
Netherlands
Switzerland
Sweden
Puerto Rico
Philippines
Portugal
15,917,868
971,377
197,225
137,623
97,609
75,999
73,888
66,436
65,704
64,092
48,663
48,087
46,755
45,925
38,601
30,435
28,181
27,794
25,764
25,081
24,827
22,260
17,683
13,558
11,350
.08° Global HYCOM snapshot: SSH and ice (gray)
May 2 model year 8
Climatological ERA15 forcing - HYCOM σ2* with 32 layers and GISS mixed layer
.08° Global HYCOM Mean Gulf Stream
And Kuroshio Pathways
Mean over four model years
ERA15 climatological wind &
thermal forcing
Global SSH Variability
Oct 92 – Nov 98 SSH
variability based on T/P,
ERS-1 and ERS-2 altimeters
(from Collecte, Localisation,
Satellites (CLS))
SSH variability from .08°
global HYCOM σ2* with
climatological wind and
thermal forcing
Velocity Cross-section Along Luzon Strait
Sb-ADCP data (top) vs. .08° global HYCOM (bottom) in the upper 300 m
Section along 21°N between 118.5°E and 124.0°E
119°E
120°E
121°E
122°E
123°E
124°E
Cross-section overlaid on
mean currents and speed
100
200
300
100
200
300
Sb-ADCP data from Liang et al. (2003, DSR Pt. II)
Mean from HYCOM with ERA15 wind and thermal forcing
No ocean data assimilation in HYCOM
m/s
NOAA/NCEP Goals for Ocean Prediction
Eddy-resolving Atlantic and Pacific Ocean prediction systems with high
resolution along the U.S. coast and ~1 week forecasts
[Participation in HYCOM NOPP GODAE project led by D.B. Rao and Carlos Lozano]
- Emphasis on US coastal regions, Loop Current, Gulf Stream
- Seamless boundary and initial conditions to regional ocean and bio-geochemical models
Coupled atmosphere-ocean-wave for hurricane forecasts
- WRF-HYCOM-WAVEWATCHIII (2007)
Eddy-permitting (1/4 or matching scale) world oceans forecast system for
medium range (up to 6 weeks)
- Boundary conditions for basin-scale ocean models
- SST estimate to support NWP (regional and global)
- Coupled global atmosphere – ocean forecast system
NOAA/NCEP Plans for Operational Ocean Prediction Systems Related to
GODAE
System
Atlantic HYCOM3
Pacific HYCOM
Resolution
4-17 km
4-18 km
1
Vert.
Coord.
Inputs2
SSH, SST, hydro,
//z
//z NCEP/GFS forcing
Target
Date
2005
2007
1
Curvilinear grid with highest resolution along the US coastline.
2
Data assimilation
- 3D Var with separable horizontal and vertical covariance for SSH, T and S
- 2D Var SST analyses are nudged into the model-estimated mixed layer
3
Running daily in real-time since 20 Sept 2005 with results on the web at
http://polar.ncep.noaa.gov/ofs/experimental
http://polar.ncep.noaa.gov/ofs/experimental/
Nowcast Velocity field at 50 m depth superposed
on the Temperature field from May 11 – June 13
NOAA/NCEP Atlantic Ocean Forecast System
Tide Gauge Comparisons for Hurricane Katrina
Pensacola,
FL
28 Aug 05
00:00
Dauphin
Island, AL
29 Aug 05
00:00
30 Aug 05
00:00
31 Aug 05
00:00
28 Aug 05
00:00
29 Aug 05
00:00
Days
28 Aug 05
00:00
29 Aug 05
00:00
Days
30 Aug 05
00:00
28 Aug 05
00:00
29 Aug 05
00:00
Days
31 Aug 05
00:00
30 Aug 05
00:00
31 Aug 05
00:00
Days
Waveland, MS
Ocean
Springs, MS
30 Aug 05
00:00
Pilot’s
Station,
LA
30 Aug 05 28 Aug 05
00:00
00:00
29 Aug 05
00:00
Days
Consistency NAT Hycom and WFS
ROMS
WFS ROMS SST and surface
velocity is shown inside the dashed
line and outside of this area is the
NAT HYCOM model.
Warm water is detached from the
Loop Current and transported
northward as mesoscale eddies
and filaments.
From A. Barth, A. Alvera-Azcárate,
R. He, R. H. Weisberg
University of South Florida
Comparison with in situ velocity


Velocity at station C15 (10m isobath).
Due to a better representation of the coast geometry, the WFS
ROMS model provides better results than the NAT HYCOM. The
OI Winds also improve the model accuracy.
From A. Barth, A. Alvera-Azcárate, R. He, R. H. Weisberg
University of South Florida
SAB Nested Finite Element Model
UNC-SAB modeling system sequence that nests the regional-scale QUODDY
implementation (middle) within the 1/12 deg operational HYCOM-GODAE model
(left). The limited-area QUODDY implementation (right) includes the estuary
and tidal inlets along the Georgia/South Carolina coast and extends to the shelfbreak.
From Brian Blanton, University of North Carolina-Chapel Hill
HYCOM, 29-31Aug 2005
Stennis, MS