The 3rd International Workshop on Next Generation Climate Models for

Advanced High Performance Computing Facilities

Tokyo, Japan, March 28 -30, 2001

Performance and Verification

of the Oil Spill Modeling System

for the Sea of JapanSergey M. VARLAMOV

Institute of Environmental Sciences, RISSHO University

E-mail: varlamov@ris.ac.jp

Jong-Hwan YOON

Research Institute for Applied Mechanics, Kyushu

University

The risk of environmental disasters related with

the spilling of oil products into the sea forces

the development of the high-quality oil spill

simulation and prediction system. It would be

an important tool for the planning of the spill

protection and spill response operations etc.

Simulation of the oil spreading and fate in the

sea is one of practical applications that

requires and integrates the results of

meteorological, oceanographical and the “oil

spill” modeling communities...

Motivations:

Where will go the oil after it was spilled in to

the sea?

- from the start of incident up to it removing from

the sea due to any processes

What will be the oil state at all stages of spill?

- density (buoyancy)

- viscosity (recovery techniques)

- emulsion state (amount to recover)

- [chemical composition - toxicity] etc.

Most important questions:

Fate of oil spilled at sea• Spreading• Horizontal and vertical transport by wind and

sea currents• Natural dispersion• Buoyancy• Emulsification• Evaporation• Dissolution• Photo-oxidation• Sedimentation and shoreline stranding• Biochemical degradation

Oil spill simulations system (Varlamov et. al., 2000)

Oil spill modelOil spill model**

Spill Transport and Weathering

Particles Tracking Model Graphical analysisGraphical analysis

subsystemsubsystem

Ocean Ocean CirculationCirculation

ModelsModels

Meteorological Meteorological subsystemsubsystem

Oil propertyOil propertydatadata

EnvironmenEnvironmentaltal

datadata

Ocean Ocean currentscurrents

datadata

MeteorologicMeteorologicalal

datadata

Oil spill Oil spill simulationssimulations

Ocean circulation models

• At nowadays the ocean circulation models is a part of system

Reasons: no products similar to meteorological analysisand forecasts, i.e. 3D currents, temperature, salinity, wavesfield are available ...

• OCM’s spatial resolution and model domain defines the scale and applicability area of the oil spill analysis and prediction system

although the simplified version with the local wind drift currents model could be applied for any area covered by meteorological forecasts and with the land-sea mask defined (GTOPO30 for the global version).

Ocean circulation models

3-D primitive equations Modular Ocean Model (GFDL MOM)- 1/6° grid (1218 km horizontal resolution)- 19 vertical levels (step 15 m in upper layers; up to 600 m below

1500 m)- rigid grid approximation

wind drift shear local current model + 2-D shallow water nonlinear model (2.5 dimensional model)

- bi-linear vertical turbulent eddy viscosity profile (Poon & Madsen, 1991)

- variable vertical step (from 1 m in upper sea layer)- 1/12° grid (69 km horizontal resolution)- 16 tidal constituents are used at the open boundaries etc.

Oil spill analysis and prediction system was tested with two types of the Japan Sea ocean circulation models:

Outline of Oil Spill Fate and Trajectory Model (year 2001 version)-1

Particles tracking model:

Spill is presented as an ensemble of particles each characterized by its properties that includes

- position on plane and the depth- diameter- density- viscosity- fraction of water in oil (emulsion)- fraction evaporated- fraction [biochemically] degradated etc.

Outline of Oil Spill Fate and Trajectory Model (year 2001 version)-2

Depending on position, model oil particles are

- transported by wind (at the sea surface)- transported by 3D sea currents- experience buoyancy effect- 3D random diffusion (wind and current dependant)- oil–coastal line interaction- evaporation at the sea surface (Fingas, 1996) - emulsification at the sea surface (Mackay et al, 1980)- biochemical degradation- [oil-sea bottom interaction]

Outline of Oil Spill Fate and Trajectory Model (year 2001 version)-3

Other model properties:

- universal 2D horizontal bicubic spline interpolation from arbitrary meteorological, bottom topography, and ocean circulation model grids (with masking of land surface meteorological data)

- initial droplet diameters distribution in accordance with observed dispersion droplet size distribution (Delvigne and Sweeney, 1988), modified by weathering processes, both “permanent” surface slick and oil dispersed into the water column are simulated

- modification of oil particles density and viscosity as result of emulsification, evaporation and biochemical degradation

- assimilation of observed oil slick position for long-term spill simulation

Technical Characteristics and the Improvement of System Performance Model properties:

- programming languages: C (system routines and meteorological GRIB data decoding software) and FORTRAN-90 (ocean circulation and spill models)

- OpenMP directives are used for the parallelization of ocean circulation and spill physical core modules

- computational effects on the parameterization of physical processes was analyzed and fixed (buoyancy-vertical diffusion-particles diameter-integration time step problem)

Routine oil spill simulation and prediction system parameters

Meteorological analysis and forecasts data are received once a day. Total 3.7 Mb are received, and at 18:00 UTC (local night) it usually takes approximately 7 - 8 minutes

SW OCM is started and run the currents simulation and prediction for 126 h (5 days). With 10s time step it takes 1 h 03 min on 667 MHz Alpha processor (GFDL MOM 1/12° - 25 min)

Oil spill simulation could be run by operator and for 5 days with 10000 droplets it will takeless then 14 min

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System Verification: Simulation of the Osung No 3 Oil Spill in the Sea of Japan

Fragment of the Ocean Circulation Model Domain in Tsushima strait area (TerrainBase topography)

Korea

Japan

Hakata

Pusan

Tsushima Isl.

Volume Transport - Camelia Line

Runing average total volume transport through Tsushima strait at the Hakata-Pusan section(‘Camelia’ Line, 03.1997-06.1999 )

3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11

0

2

4

6 Monitoring results (Data of Takikawa & Yoon, 2000)•Total

•Eastern Channel

•Western Channel

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Down Left

3.5Sv 3.0 Sv 2.5 Sv 2.0 Sv 1.5 Sv 1.0 Sv

-1.0 Sv 1.580.666

0.920.35

0.230.05

-0.5 Sv

0.0 Sv 2.401.06

1.710.75

1.040.43

0.5 Sv 2.471.10

2.120.94

1.770.79

1.0 Sv 3.251.46

2.541.14

2.190.98

1.840.83

1.500.68

1.5 Sv 2.611.18

2.261.03

1.910.87

Takikawa -original data

Takikawa -after tides

elimination

Model:TerrainBase

Total:mean/stddev

2.253.60

2.481.06

2.504.04

East:mean/stddev

0.891.83

1.040.70

1.101.73

West:mean/stddev

1.362.81

1.440.57

1.401.71

Model simulationswith TerrainBasetopography

Model simulations with smoothed ETOPO5topography(Eastern/Western channel volume transport ~2.2 when ~0.8 expected)

Tidal Sea Level Variations

5 10 15

-100

0

100

5 10 15

-100

0

100

Idzuhara (upper) and Hakata (lower) tidal stations, February 2000Observed (blue, black) and simulated(red) sea level anomalies, cm.

RMS Error = 12 cm

RMS Error = 9 cm

- 229 kl of Bunker C oil spilled

- Largest part of oil was recovered(April 8-9)

- April 9, 1997 15:45 JST coastline ofN.Tsushima Isl. was polluted

Animated Simulation Results:Push on the map to start demonstration, esc to stop it, the label fields pass to the next slide.

Model particles in upper 2 m layer, size by color.Sea current and surface wind drift (4% of wind speed)

Oil spill accident with Korean tanker Osung No 3

Oil concentration in upper 2 m layer

It is strongly related with the model particles size and trace mainly

the surface drifting slick position

Oil concentration in upper 2 m layer

It is strongly related with the model particles size and trace mainly

the surface drifting slick position

Animated Simulation Results:Push on the map to start demonstration, esc to stop it, the label fields pass to the next slide.

Sea current and surface wind drift (4% of wind speed)

Tanker Osung No 3 oil spill incident simulation

Relative mass of oil stranded at the shoreline

Relative mass of oil stranded at the shoreline

Some spill model integral parameters

Mean (volume weighted) diameterof floating model oil particles, m

Mean (volume weighted) diameterof floating model oil particles, m

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4000

6000

8000

10000

Total number of active modeloil particles

Total number of active modeloil particles

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0

500

1000

1500

4 5 6 7 8 9 10 11 12 13

0

50

100

150

4 5 6 7 8 9 10 11 12 13

0

200000

400000

Mean (volume weighted) dynamicviscosity of floating oil, cP

Mean (volume weighted) dynamicviscosity of floating oil, cP

Conclusion

Oil spill numerical simulation system

could provide important information for

the short term (at least up to 4-5 days)

planning of accidental oil spill recovery

operations