Transcript Present and Future U.S. navy Operational Prediction Systems P.J. Hogan1, H.E. Hurlburt1, O.M.

Present and Future U.S. navy Operational
Prediction Systems
P.J. Hogan1, H.E. Hurlburt1, O.M. Semdstad2, J.A. Cummings1,
E. J. Metzger1
1Naval
Research Laboratory
2Planning Systems, Inc.
http://www.hycom.org
2nd Meeting of the GCOOS Parties
New Orleans, LA
6-7 March 2007
Outline
Current real-time operational ocean products
-> 1/4° MODAS Analysis
-> 1/8° global NCOM (~17 km) + 1/32° global NLOM (~3.5 km)
Near real-time demonstration products
-> 1/24° Intra Americas Sea (IAS) NCOM (~6 km)
-> 1/12° North Atlantic HYCOM (~7 km)
-> 1/25° Gulf of Mexico HYCOM (~3.5 km)
Real-time pre-operational products
-> 1/12° Global HYCOM (~7 km)
NRL – R & D, transitions
NAVOCEANO - Primary operational customer
MODAS = Modular Ocean Data Assimilation System (data analysis)
NCOM = Navy Coastal Ocean Model (σ-z)
NLOM = Navy Layered Ocean Model (quasi-isopycnal)
HYCOM = Hybrid Coordinate Ocean Model (σ-z-ρ)
Global Components
NRL Layered Ocean Model
NLOM at 1/32° resolution provides
global mesoscale representation
NLOM assimilates altimeter SSH and
satellite SST
MODAS provides vertical inference
from NLOM
Navy Coastal Ocean Model
NCOM at 1/8° resolution has higher
vertical structure than 1/32° NLOM
NCOM assimilates vertical
information.
Overall, the system maintains the
deep ocean eddies and represents
the vertical thermal structure.
MODULAR OCEAN DATA ASSIMILATION
SYSTEM (MODAS)
Used for the assimilation of data into operational prediction systems
NAVOCEANO
MCSST & Altimetry
Air, Buoy, & Ship XBTs
Remote Sensors
Daily output to the fleet
Compressed
Oceanographic Data
Global Data Fusion
METOC Centers
Local XBT Measurements
Regional Fusion &Tailored
Operational Support
1/8° Global Navy Coastal Ocean Model (NCOM G8)
Objectives
real-time fully global ocean
forecast system providing
• short-term upper
ocean predictions
• initial/boundary
conditions for real-time
regional models
• ice model host (PIPS 3)
• ocean capability
suitable for a global
coupled air/ocean
system (NOGAPS)
SST
NCOM G8
• 3 day hindcast/5 day
forecast once per day
Several products available at http://www7320.nrlssc.navy.mil
°C
Data Assimilation for Global
NCOM
Surface flux
SST & SSS
ALPS
1/32° NLOM
SSH
IN SITU DATA
MODAS 3D
SST
MODAS 2D
MCSST
3D T & S
Relaxation
Global NCOM nesting into coastal systems
ADCIRC 1 km
MS Bight
HYCOM 0.08°
Intra-Americas Sea
SST
May 4
ADCIRC 100 m
Bay St. Louis, MS
1/24° (6 km) Intra Americas Sea NCOM Nowcast/forecast System
SSH Nowcast for march 4, 2007
Courtesy D.S. Ko, NRL
• 72-hour forecast once per day*
• Assimilates SSH, SST
• Forced with NOGAPS
• BC’s from global NCOM
• 41 σ-z levels
• 53 rivers
* Runs in non-dedicated queue
http://www7320.nrlssc.navy.mil/IASNFS_WWW/
NLOM/NCOM -> HYCOM
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Replace the NCOM/NLOM with the HYbrid Coordinate
Ocean Model (HYCOM)
NLOM: ~30x computationally faster than HYCOM and most
other ocean models but has low vertical resolution and
excludes most shallow water and the Arctic
HYCOM: includes shallow water to 5-10 m and can include
the Arctic
 Hybrid (generalized) isopycnal/terrain-following (σ)/depth
(z-level) coordinates
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Optimal coordinate is chosen dynamically in space and
time via the layered continuity equation
Accurately transitions between shallow and deep water
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Generalized – not limited to these types
A very challenging problem in ocean modeling
Development is a community effort
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International HYCOM Consortium
Alan Wallcraft (NRL) is in charge of developing and maintaining the
standard version of the model
1/12º Atlantic HYCOM
25 October, 2006
Snapshot of Sea Surface Height
Dynamic σ-z-ρ vertical coordinate
• 10-day hindcast, 14 day forecast
once per week
• Provides boundary conditions
to coastal models
• 26 layers, ~8 km resolution
• Assimilates 1/4° gridded MODAS
(assim of surface observations only)
• Vertical projection via Cooper and Haines
• NOGAPS forcing
• Relaxation to MODAS SST
http://www7320.nrlssc.navy.mil/ATLhycom1-12/skill.html
http://www.hycom.org
1/12° Atlantic HYCOM
SSH in Gulf Stream and Gulf of Mexico region
25 October, 2006
White/black line is the frontal analysis of MCSST observations performed at
NAVOCEANO. Black line represents data more than four days old.
NCODA Data Assimilation in HYCOM
 Data for assimilation
- Sea surface height (SSH) from satellite altimetry
- Sea surface temperature (SST)
- Temperature and salinity (T&S) profiles
- Other data later
 Downward projection of surface data
- Cooper and Haines (1996)
Both options are in NCODA
- Synthetic T&S profiles
- Data assimilation technique covariances
]
 Data assimilation techniques
- MVOI – Used by NCODA, primary data assimilation package in HYCOM
- 3DVAR – Planned as a future upgrade in NCODA
- Ensemble Kalman filter
Computer code and expertise in hand. For later addition
- Representer adjoint method
to nested models or small subregions of the global model
- Reduced Order Information Filter (ROIF) – Under development at U. Miami/JPL
}
 The ocean model is an integral component of the data assimilation
- Dynamical interpolation/forecast skill strongly impact data assimilation results
- Model forecast used as a first guess for ocean analysis
- Ocean model converts atmospheric forcing into oceanic information
NRL Coupled Ocean Data Assimilation (NCODA)
Ocean Obs
SST: GAC/LAC
MCSST, GOES,
Ship, Buoy
Profile: XBT, CTD,
PALACE Float,
Fixed Buoy,
Drifting Buoy
Altimeter SSHA
SSM/I Sea Ice
Sequential Incremental Update Cycle
Analysis-Forecast-Analysis
Ocean QC
Forecast Fields
Prediction Errors
Innovations (obsfirst guess)
3D MVOI
First Guess
Increments
HYCOM Model
MVOI - simultaneous analysis 5 ocean variables
temperature, salinity, geopotential, velocity (u,v)
GULF OF MEXICO HYCOM
CONFIGURATION
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Horizontal grid: 1/12° or 1/25° (517 x 349
grid points,
3.5 km spacing on average)
18°N to 31°N
20 vertical coordinates
Bathymetry: 2m coastline
Surface forcing from FNMOC/NOGAPS
Monthly river runoff
Nested Boundary:
relaxation to the 1/12° Atlantic HYCOM
climatological T, S, U and V along open
boundary
1/25º HYCOM Gulf of Mexico Real-time System
Daily nowcast/forecast sequence
7 day forecast
5 day hindcast
Daily
Analysis wind and
Forecast wind and
thermal forcing;
thermal forcing
Assimilation of
Revert toward
Observations from
climatological wind and
Satellites and in situ
thermal forcing,
profiles
Relaxation to climatologically
corrected SST
HYCOM identical twin results
“Observed” track and MCSST locations
Truth
29 August 1999
Analysis, day 1
Initial state from
one year earlier
Truth
18 October 1999
Analysis, day 50
HYCOM identical twin results
“Observed” track and MCSST locations
correction increments
SSH
SST
29 August 1999
Day 1
18 October 1999
Day 50
HYCOM identical twin results
“Observed” track and MCSST locations
correction increments
T
S
200m
29 August 1999
Day 1
18 October 1999
Day 50
HYCOM identical twin results
Temperature and salinity sections along 25.08ºN
“Observed” track and MCSST locations
T
T
Analysis, day 1
29 August 1999
Truth
S
S
T
T
Analysis, day 50
18 October, 1999
Truth
S
S
1/25º Gulf of Mexico HYCOM
Hindcast started 2 September 2003
SSH
14 February 2005
SST
HYCOM nowcast SSH with the NAVO frontal analysis of
MCSST observations (white/black lines, black data > 4 days old)
1/25º Gulf of Mexico HYCOM
Hindcast started 2 September 2003
14 June 2006
Climatological boundary condition
Boundary condition from 1/12º Atlantic
HYCOM nowcast SSH with the NAVO frontal analysis of
MCSST observations (white/black lines, black data > 4 days old)
SSH Observations being assimilated into 1/25° HYCOM
Each frame contains up to 3 days of SSH obs
In Situ SST Observations being assimilated into 1/25° HYCOM
Each frame contains one day of in situ observations
Satellite SST observations going into 1/25° HYCOM
Each frame contains one day of satellite SST observations
Synthetic Observations going into 1/25° HYCOM
Based on satellite SSH, used for 3-D T/S correction
Each frame contains one day of synthetic observations
Global HYCOM Configuration
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Horizontal grid: 1/12° equatorial resolution
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4500 x 3298 grid points, ~6.5 km spacing on average, ~3.5 km at pole
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Mercator 79°S to 47°N, then Arctic dipole patch
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Vertical coordinate surfaces: 32 for σ2*
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GISS mixed layer model
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Thermodynamic (energy loan) sea-ice model
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Surface forcing: wind stress, wind speed, thermal forcing,
precipitation, relaxation to climatological SSS
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Monthly river runoff (986 rivers)
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Initialize from January climatology (GDEM3) T and S, then SSS
relaxation from PHC 3.0
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No subsurface relaxation to climatology
NCODA Assimilation 1/12° Global HYCOM snapshot: SSH and ice (gray)
May 2 model year 8 with climatological forcing
• Ran under DoD Grand Challenge Computer Grant in 2006
• 190K CPU hrs/model year on 784 CPUs (23 wall hrs/month)
• 3 TB/model year for compressed daily 3-D output (250 GB/day compressed)
HYCOM Long-term Goals for Operational Ocean Prediction
 .08 fully – global ocean prediction system transitioned to
NAVO in 2007
 ~7 km mid-latitude resolution
 Include shallow water, minimum depth 5m
 Bi-polar (PanAm) grid for Arctic
 FY04-06 DoD HPC Challenge project essential
 Embedded ice model
 Increase to .04 resolution globally and transition to NAVO by
the end of 2011
 ~3.5 km mid-latitude resolution
 Good resolution for coastal model boundary conditions globally
 “Baseline” resolution for shelf regions globally
 Input to atmospheric and bio-chemical models
 John Kindle has NOPP funding for bio-chemical model
coupling to HYCOM
1/12° Global HYCOM in GoM
Comparison of SSH in the
Gulf of Mexico
Feburary 25, 2007
Both models use NCODA assimilation
1/25° Nested Gulf of Mexico HYCOM
Global HYCOM scheduled to be
transitioned to 1/25° in 2011
4 Nowcast/Forecast Systems Compared with SeaWiFS Ocean Color
Sea Surface Height (SSH) overlain on SeaWiFS ocean color in Gulf of Mexico
SST and altimeter SSH from GFO and Jason-1 were assimilated
Atmospheric forcing was from FNMOC/NOGAPS
User Interest in Real-time Global Ocean Products
NRL Oceanography Division Web Site Hit Statistics during 2005
1,526,968
36,452,092
Avg hits/day
# hits used in country breakdown
99,869
36,342,270
# countries with  1000 hits
70
# countries with  100 hits
127
Total number of countries
181
Includes the following real-time global
Ocean products and other results
Altimeter data
MODAS SSH & SST analyses
Ocean prediction systems
1/16 and 1/32 global NLOM
1/8 global NCOM
1/12 Atlantic HYCOM
Top 25 Countries and # Hits
Total # U.S. Military hits
Total # hits
United States
Japan
Taiwan
China
Russia
Germany
Great Britain
Greece
Spain
Canada
France
Mexico
Philippines
Vietnam
South Korea
Italy
Australia
Singapore
New Zealand
Sweden
India
Denmark
Peru
Netherlands
Norway
27,468,102
7,190,216
152,085
150,733
109,211
103,376
98,845
88,603
72,452
66,011
62,260
60,198
56,034
53,749
53,536
42,297
41,128
40,215
37,724
36,014
27,820
26,664
25,642
24,191
22,805
Unclassified
END
Approved for Public Distribution
www.ocean.nrlssc.navy.mil/
• ALPS
• MODAS
• 1/32° Global NLOM
• 1/16° EAS NCOM
• 1/24° IAS NCOM
• 1/12° Atlantic HYCOM
• 1/8° Global NCOM
• And others!
1/12º Global HYCOM
Hindcast started 12 November 2003
SSH 12 November 2003
1/12º Global HYCOM
Hindcast started 12 November 2003
SSH 12 November 2003
Comparison of Model Sea Surface Height in
the Gulf of Mexico with SeaWIFS
1/32 Global NLOM
0.08
0.1
0.2
0.4
0.6
1/16 Global NLOM
Chlorophyll
mg/m^3
1.0
SSH
cm
Model sea surface height from 28 Aug 2003 overlain on
SeaWIFS chlorophyll concentration from 22-28 Aug 2003
www7320.nrlssc.navy.mil/global_nlom
GULF OF MEXICO MODEL CONFIGURATION
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Horizontal grid: 1/12° (258 x 175 grid points,
6.5 km spacing on average)
18°N to 31°N
20 vertical coordinates
Bathymetry: 5m coastline
Surface forcing from FNMOC/NOGAPS
Monthly river runoff
Nested Boundary:
relaxation to the 1/12° Atlantic HYCOM T, S,
U and V along open boundary, (no assimilation
in these experiments)
Models
nested in
NCOM G8
Galicia
Chesapeake
WCST
Adriatic
IAS
EAS
Global NCOM
MED
1/25º Gulf of Mexico HYCOM
Hindcast started 2 September 2003
29 May 2006
Climatological boundary condition
Boundary condition from 1/12º Atlantic
HYCOM nowcast SSH with the NAVO frontal analysis of
MCSST observations (white/black lines, black data > 4 days old)
Analysis of SSH from 1/12° Global
HYCOM with NCODA assimilation*
November 6, 2003 SSH Analysis
*Increase in computer runtime is ~30%