Application of HYCOM in Eddy-Resolving Global Ocean Prediction

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Application of HYCOM in Eddy-Resolving Global
Ocean Prediction
Part of HYCOM/GODAE project sponsored by the
National Ocean Partnership Program
Community Effort NRL, Florida State, U. of
Miami, GISS, NOAA/NCEP, NOAA/AOML, NOAA/PMEL,
PSI, FNMOC, NAVOCEANO, SHOM, LEGI, OPeNDAP, UNC,
Rutgers, USF, Fugro-GEOS, Orbimage, Shell,
ExxonMobil
Presented by Harley Hurlburt Naval Research
Laboratory Stennis Space Center, MS
USA International GODAE Steering Team
Meeting NOAA/CPO Silver Spring, MD 2-4 June 2008
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U.S. Navy Present and Planned Global Ocean
Prediction Systems
Global Product Mid-Lat Resolution Vert. Coord. Inputs Run By Actual or Target Date
1/16? NLOM 7 km Layered SSH, SST, hydro, FNMOC NOGAPS Atmospheric Forcing NAVO OP 9/01-3/06
1/8? NCOM 1 15 km ?/z SSH, SST, hydro, FNMOC NOGAPS Atmospheric Forcing NAVO OP 2/06
1/32? NLOM 2 3.5 km Layered SSH, SST, hydro, FNMOC NOGAPS Atmospheric Forcing NAVO OP 3/06
1/12? HYCOM 3,5 7 km ?/?/z SSH, SST, hydro, FNMOC NOGAPS Atmospheric Forcing NAVO 2007
1/25? HYCOM 3.5 km ?/?/z SSH, SST, hydro, FNMOC NOGAPS Atmospheric Forcing NAVO 2012
Near Real-time demonstration Near Real-time demonstration Near Real-time demonstration SSH, SST, hydro, FNMOC NOGAPS Atmospheric Forcing
1/12? Atl. HYCOM 4,5 7 km ?/?/z SSH, SST, hydro, FNMOC NOGAPS Atmospheric Forcing NRL 2002
OP operational 1 High vertical resolution for
mixed layer prediction. Assimilates SSH from NLOM
via T and S synthetic profiles. Web page
http//www.ocean.nrlssc.navy.mil/global_ncom 2
Web page http//www.ocean.nrlssc.navy.mil/global_n
lom 3 Running in real time at NAVO. 4 Under the
National Ocean Partnership Program (NOPP), 1/12?
Atlantic HYCOM demo is running in near
real-time. Includes the Mediterranean Sea. 5
Results at http//www.hycom.org (100Tb LAS server
at FSU)
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HYCOM HYbrid Coordinate Ocean ModelNCODA
Navy Coupled Ocean Data Assimilation

• Delivery
• Scheduled for transition to the Naval
  Oceanographic Office in 2008
• Capability
• Provide accurate 3D temperature, salinity and
  current structure
• Depict the location of mesoscale features fronts
  and eddies
• Progress
• 1/12 global HYCOM/NCODA running in real-time in
  the NAVOCEANO operational queues since 22 Dec
  2006
• Produces daily 5-day hindcast up to the nowcast
  time, then a 5-7 day forecast
• 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)

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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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2004-2006 Mean Currents and Speed at 150 m 1/12
non-assimilative global HYCOM
2004-2006 Transport (Sv) INSTANT / 05.8 / 09.7
Lifamatola Pass (deep overflow) 2.9 / 2.0 / 0.5
Makassar Strait 11.5 / 7.3 / 6.7
Lombok Strait 2.2 / 2.4 / 2.5
Ombai Strait 3.1 / 5.1 / 2.9
Timor Pass 7.6 / 5.9 / 5.8
m/s
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Makassar-West Velocity Time Series INSTANT
Mooring (black) vs. GLBa0.08-09.7 (red)
Meridional velocity anomaly wrt observed and
simulated mean
50 m
150 m
350 m
750 m
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Snapshot of Steric SSH Amplitude Due to the M2
Internal Tide
5 cm
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Demonstration of internal tidal signature at the
surface from a 1-month simulation using
32-layer, 1/12 global HYCOM with wind forcing
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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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Satellite Availability - 2007 24 hour data
window
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1/12º Global HYCOM
1/25º GULF OF MEXICO HYCOM
1/12º Atlantic HYCOM
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RMS SSH at ground track points from GFO,
ENVISAT, Jason, and interleaved TOPEX satellite
altimetry, 8 years of altimeter data
Courtesy Gregg Jacobs Naval Research Laboratory
RMS SSH from 1/25 HYCOM Over 2000-2007 with 1/2
NOGAPS surface forcing and NCODA assimilation
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1/25º GOM HYCOM currents
13 March 2007 1500Z
From Erick Rogers, Naval Research Lab.
Wave prediction without accounting for currents
Wave prediction with accounting for currents