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NOGAPS Navy Operational Global Atmospheric Prediction System Complex Data Quality Control Atmospheric Analysis: Multivariate Optimum Interpolation Analysis (MVOI) of Winds and Heights Univariate Analysis of Moisture Ocean Analysis: 2D Optimum Interpolation Analysis of SST 3D Ocean MVOI of T, S, SSH, Sea Ice, and Currents Nonlinear, Normal Mode Initialization Hydrostatic, Spectral Atmospheric Model: Cumulus Parameterization (Emanuel, MWR 1999) Shallow Cumulus Parameterization (Tiedtke, ECMWF Report 1984) PBL Parameterization (Louis, BLM 1982) Radiation Parameterization (Harshvardhan et. al., JGR 1987) Convective and Stratiform Cloud Parameterization (Teixeira and Hogan, JC 2002) Gravity Wave Drag (Palmer et. al., QJRMS 1986) Parallel Ocean Program (POP) Ocean Model Features: Over 16,000 Operational Forecasts run at FNMOC 6 Hour Incremental Data Assimilation Cycle Current Operational Resolution: T239 (~55 km), 30 Vertical Levels Approximately 11 minutes/forecast day wall time using 120 O3K processors Track Forecasts for all Tropical Cyclones w/max wind > 50 knots Supplies Boundary Conditions to Mesoscale and Wave Models
Citation preview
Air/Ocean Coupled Prediction Systems at NRL
MRYRichard M. HodurNaval Research Laboratory
Monterey, CA
8th HYCOM Workshop19-21 August 2003Camp Springs, MD
Air/Ocean Coupled Prediction Systems at NRL MRY
Outline
•Global Air/Ocean Coupled Modeling:•NOGAPS/POP•Validation of one-way coupled system•Development of two-way coupled system
•Mesoscale Air/Ocean Coupled Modeling:•COAMPS/NCOM•Focus on Mediterranean:
•Adriatic Circulation Experiment•Real-Time Testbed
•Summary/Plans
NOGAPSNavy Operational Global Atmospheric Prediction System
•Complex Data Quality Control•Atmospheric Analysis:
• Multivariate Optimum Interpolation Analysis (MVOI) of Winds and Heights• Univariate Analysis of Moisture
•Ocean Analysis:• 2D Optimum Interpolation Analysis of SST• 3D Ocean MVOI of T, S, SSH, Sea Ice, and Currents
•Nonlinear, Normal Mode Initialization•Hydrostatic, Spectral Atmospheric Model:
• Cumulus Parameterization (Emanuel, MWR 1999)• Shallow Cumulus Parameterization (Tiedtke, ECMWF Report 1984)• PBL Parameterization (Louis, BLM 1982)• Radiation Parameterization (Harshvardhan et. al., JGR 1987)• Convective and Stratiform Cloud Parameterization (Teixeira and Hogan, JC 2002)• Gravity Wave Drag (Palmer et. al., QJRMS 1986)
•Parallel Ocean Program (POP) Ocean Model•Features:
• Over 16,000 Operational Forecasts run at FNMOC• 6 Hour Incremental Data Assimilation Cycle• Current Operational Resolution: T239 (~55 km), 30 Vertical Levels• Approximately 11 minutes/forecast day wall time using 120 O3K processors• Track Forecasts for all Tropical Cyclones w/max wind > 50 knots• Supplies Boundary Conditions to Mesoscale and Wave Models
NOGAPS
Ocean MVOI Ocean Model(POP)
T, S, v
NAVDAS
Fluxes, StressesSST
T, q, v
Fully Coupled NOGAPSAir-Ocean with Data Assimilation/Forecast Cycle
MVOI: Multivariate Optimum Interpolation AnalysisPOP: Parallel Ocean Prediction Model
NOGAPS/POP Coupled ModelingComparison of Average 5 m Temperature Analysis Error Correction (Top) with
Forecast Model Correction (Bottom) for August 2000
Reduced errors demonstrate importance of model to data assimilation
Analysis-only produces significant errors in coastal
boundary currents
NOGAPS/POP Coupled ModelingNOGAPS/MVOI/POP Results: SST RMS Errors, Forecast vs Persistence
POP: 1/2 degree, 75S-75N, NOGAPS T159 Forcing
SST RMS Forecast Statistics for CY 2002
NOGAPS/Coupled Models Transition StatusComparison of Modeled (Top) and Observed (Bottom) SSH Variability
POP model was able to simulate SSH
variability in many regions. Direct
assimilation of SSH is expected to improve
results.
POP model run without assimilating
SSH
Plots are for calendar year 2002
Coupled Mesoscale Modeling of the Atmosphere and Ocean
Approach•Utilize existing mesoscale atmosphere and ocean data assimilation systems:
•Atmospheric data assimilation system in the Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS™)
•3-dimensional ocean multivariate optimum interpolation analysis (3D OMVOI)
•NRL Coastal Ocean Model (NCOM)•Initial tests of the coupled system: Focus on the Mediterranean Sea
•Active meteorologically and oceanographically•Navy relevance•Minimizes need for lateral boundary conditions for ocean model
COAMPSTM is a trademark of the Naval Research Laboratory
COAMPS™Coupled Ocean/Atmosphere Mesoscale Prediction System
•Complex Data Quality Control•Analysis:
•Atmosphere: MVOI of u, v, and Heights; Univariate of T, q•Ocean: 2D SST; 3D MVOI of T, S, SSH, Sea Ice, and Currents
•Initialization:•Atmosphere: Hydrostatic Constraint on Analysis Increments, or Digital Filter•Ocean: Stability check
•Model:•Atmosphere:
• Numerics: Nonhydrostatic, Scheme C, Nested Grids, Sigma-z, Flexible Lateral BCs• Parameterizations: PBL, Convection, Explicit Moist Physics, Radiation, Surface Layer
•Ocean: Navy Coastal Ocean Model (NCOM)• Numerics: Hydrostatic, Scheme C, Nested Grids, Hybrid Sigma/z• Parameterizations: Mellor-Yamada 2.5
•Features:• Globally Relocatable (5 Map Projections)• User-Defined Grid Resolutions, Dimensions, and Number of Nested/Parent Grids• Incremental Data Assimilation; Atmosphere - 6 or 12 hours; Ocean - 12 or 24 hours• Applicable for Idealized or Real-Time Applications• Single Configuration Managed System for All Applications
•Operations (Atmospheric Components plus 2D SST Analysis):• FNMOC: 8 Areas, 4 runs/day, grid spacing as low as 6 km, forecasts to 72 hours• Navy Regional Centers: 2 runs/day, grid spacing as low as 3 km, forecasts to 48 hours
COAMPS is a registered trademark of the Naval Research Laboratory
COAMPS™Coupled Ocean/Atmosphere Mesoscale Prediction System
Existing Future
QCPreprocessing
and MVOI Analysis
Initialization and Forecast
QCPreprocessing
and OMVOI Analysis
Initialization and Forecast
Atm
osph
ere
Oce
an
COAMPS is a registered trademark of the Naval Research Laboratory
Atmospheric ReanalysesPurpose: Generate high-resolution fields for forcing NCOM
• Cold start at first analysis time• 12 h incremental data assimilation cycle• Hourly output from forecast model• Analysis include SST analysis for each grid
Analysis
COAMPS 24 h Forecast
Analysis
COAMPS 24 h Forecast
Analysis
COAMPS 24 h Forecast
Observations
Observations
Observations
NOGAPS Fields
NOGAPS BC’s
NOGAPS BC’s
NOGAPS BC’s
12h fcst
12h fcst
12h fcst
Result:Hourly surface
forcing fields for extended time
periods
Atmospheric ReanalysesAverage 10 m winds for Oct 98 using Data Assimilation and Cold Starts with 27 km Resolution
Hours 0-11 of all forecasts used
Results indicate
that horizontal resolution
is important to capture gap flow and other surface-forced events
correctly27 km
81 km
10
5
0
Win
d Sp
eed
(m/s
)
Atmospheric ReanalysesAverage 10 m winds for Oct 98 using hourly output from 27 km grid
Hours 0-11 of all forecasts used
Results indicate
thatdata
assimilation reduces
model spin-up as
evidenced by stronger
winds in gap flow
regions and along
coastlines
Data Assimilation
Cold Start
10
5
0
Win
d Sp
eed
(m/s
)
•Atmosphere:•Bora: Strong, localized
northeasterly winds around Istrian peninsula
•Scirocco: Strong, warm southeast winds
•Ocean:• Cyclonic cells in the central
and southern regions• River runoff and strong winds
create large variability in the northern Adriatic
Bora
Po River
Ocean-Atmosphere Nested Modeling of the Adriatic Sea during Winter and Spring 2001
Meteorology and Oceanography in the Adriatic
1. Generate 27 km atmospheric forcing fields over the Med2. Generate 6 km, 2-year spin-up of the Med using forcing from
#1, then 12-hour data assimilation for October 19993. Generate 4 km atmospheric forcing fields over the Adriatic Sea4. Generate 2 km Adriatic forecasts using initial conditions and
inflow from #2, and atmospheric forcing from #3, 1/28/01-6/4/01
Objectives• Simulate Adriatic
atmospheric and oceanic circulation at high resolution
• Document and understand response of the shallow northern Adriatic waters to forcing by the Bora and Po river run-off
• Quantify the effects of coupling (e.g., one-way, two-way, frequency, resolution) on atmosphere and ocean forecasts
• Aid in planning and interpreting Adriatic Circulation Experiment (ACE) observations
6 km NCOM
27 km
81 km COAMPSTM
2 km NCOM
36 km
12 kmCOAMPSTM
13
2
4
4 km
Momentum, Heat fluxes
Initial conditions and lateral boundary forcing
Mom
entum,
Heat fluxes
Ocean-Atmosphere Nested Modeling of the Adriatic Sea during Winter and Spring 2001
Design of Experiment
Comparison of observed 10 m winds to observations and 25 m ocean current to observations
Comparison of 36 km and 4 km atmospheric winds
Results(1) 4 km and 36
km winds have similar correlation to observations
(2) Ocean model performs better with 4 km winds
Atmosphere
Ocean
(1)
(2)
Results suggest that the consideration of the effects on an ocean model should be a metric in the validation of
atmospheric models and that high-resolution forcing fields improve ocean forecasts
27 km 4 km
Collaboration with Adriatic Circulation Experiment (ACE)
COAMPS™ Fields: 5 October 1999Resolution Comparison: Atmospheric Forcing
Collaboration with Adriatic Circulation Experiment (ACE)2 km NCOM Fields: 5 October 1999
Comparison of Ocean Model Results Using Atmospheric Fields with Different Resolutions
27 km forcing 4 km forcing
Collaboration with Adriatic Circulation Experiment (ACE)Animation of 2 km Adriatic NCOM Simulation for Oct 1999
Hank Perkins, NRL SSC, Version of 06 Oct 2002
Ocean-Atmosphere Nested Modeling of the Adriatic Sea during Winter and Spring 2001
Field Program (2002-2003): Current Measurements
Split
I t a l yAncona
Po
VeniceTrieste
50
100
200NRL, Perkins, 06 Oct 2002
Adige
Piran20 S l o v e n
i a
Paguro Marine Park
x
x
RovinjC r o a t i a
••
•
x
Senigallia
Cesenatico
Max WERArange: 120 km
12
6
8
10
7
SS Line
4
9
5
3
IC
12
KB Line
ND L
ine1
2
VR Line
12
3 45
6
CP Line
12
34
56
LEGEND
Center: SEPTR
Center+NRL: ADCP
IRPEM: CM MooringIBM: C10 Mooring
OGS: Met + CM BuoyNIB: Met + CM Buoy
ISDGM: Tower
OGS and U. Hawaii: WERA Radars (3)
IOF: ADCP
OGS: Wave Buoy
OGS: Codars (3)
+ WTG (+ Sal)
IRB: ADCP or RCM
EuroStratiform: ADCP
Real-Time Ocean Data Assimilation/Forecast Test-Bed
Ocean Analysis/Model Components
Real-time ocean data assimilation run on NRL SGI O2K
MVOI, obs from GODAE Server
NCOM (6 km)72h forecast
Cold Start:First-guess: GDEM, Global NCOM, or POPQC observations/MODAS syntheticsMVOI (z-levels)Initialization5-day spin-up
Warm Start:First-guess: NCOM 12 h forecastQC observationsMVOI (z-levels)Increments added to first-guessInitialization
Hourly Atmospheric Stresses and Fluxes (27 km) from
FNMOC COAMPS™ forecast,Lateral Boundary ConditionsFrom Global NCOM or POP
12h 12hNCOM (6 km)72h forecast
MVOI, obs from GODAE Server
SST
to
Atm
osph
eric
Mod
el
SST
to
Atm
osph
eric
Mod
el
Hourly Atmospheric Stresses and Fluxes (27 km) from
FNMOC COAMPS™ forecast,Lateral Boundary ConditionsFrom Global NCOM or POP
COAMPS™/NCOM Web Page
NCOM Sea Surface Temperature12-21 May 2003: Hours 1-12
Climate Guess Analysis Climate Guess Analysis N
All Data Combined -0.277 -0.03 0.003 0.557 0.262 0.101 4133
ERI SHIP -0.699 -0.182 0.113 1.657 0.598 0.426 24Fixed BUOY Temp 0.029 -0.238 0.006 0.422 0.498 0.129 3Drifting BUOY Temp 0.067 -0.159 -0.049 0.386 0.207 0.146 19N14 Night MCSST -0.277 -0.029 0.003 0.545 0.258 0.093 4072Bucket SHIP -0.711 -0.363 0.261 0.761 0.44 0.387 4Hull Sensor SHIP -0.045 0.117 -0.163 0.334 0.436 0.398 11
Mean Bias (C) RMS Error (C)Analysis Verification at 2003020600: SST
Data Type
Sample Validation of SST AnalysisOutput from Ocean MVOI for Real-Time Mediterranean Run at
0000 UTC 6 March 2003
Similar statistics calculated at each analysis time for all variables at all analysis levels
Statistics indicate that OMVOI/NCOM is performing better than climatology or persistence
Preliminary results
suggest that significant differences exist when forcing an
ocean model with 12 h
frequency as opposed to 1
h or 6 h frequency
12 h frequency runs
1 h and 6 h frequency runs
Importance of Temporal Resolution of Ocean Forcing
Comparison of NCOM runs using 1 h, 6 h, and 12 h COAMPS™ forcingComparisons for Gulf of Lion during February 1999
Application of COAMPS™/NCOM in Eastern Pacific
Cold Start Initial Fields and Lateral Boundary Conditions from Global NCOM
SST: tau 0
SST: tau 72
Surface currents: tau 0
Surface currents: tau 72
•Global:•Testing NOGAPS/POP one-way coupled system•Starting two-way coupled tests•Transition to HYCOM for global ocean prediction
•Mesoscale:•Atmospheric Reanalyses
• Importance of horizontal resolution• Importance of data assimilation
•Air-Ocean Coupling• Use unfiltered, native grid fields for ocean forcing• Collaboration with Adriatic Circulation Experiment (ACE)
• New metric for model verification• Importance of horizontal resolution of ocean forcing
• Importance of temporal resolution of ocean forcing• Real-time ocean data assimilation/Forecast test-bed
•Build in HYCOM for Initial/Lateral Boundary Conditions•Two-way coupling
Air/Ocean Coupled Prediction Systems at NRL MRY
Summary/Plans