Bonn Agreement Oil Appearance Code Bonn Agreement Oil Appearance - PowerPoint PPT Presentation

Bonn Agreement Oil Appearance Code Bonn Agreement Oil Appearance Code BAOAC BAOAC

Bonn Agreement Oil Appearance Code Bonn Agreement Oil Appearance Code A correlation between the visual appearance and A correlation between the visual appearance and the thickness of oil on the sea the thickness of oil on the sea used to estimate spilled oil volume used to estimate spilled oil volume

Developing the BAOAC Developing the BAOAC • Literature survey (1997) • Literature survey (1997) – Who had claimed what and when ? Scientifically justified ? Who had claimed what and when ? Scientifically justified ? – • Laboratory studies • Laboratory studies – Thin oil films studied under laboratory conditions Thin oil films studied under laboratory conditions – • Fjord studies • Fjord studies – Small Small- -scale outdoor experiments scale outdoor experiments – • Bonnex 2002 • Bonnex 2002 – Full Full- -scale experiments at sea scale experiments at sea –

The BAOAC The BAOAC Code Appearance QUANTITY Thickness Code Appearance QUANTITY Thickness µ m) ( µ 3 / km 2 m 3 / km 2 m) m ( 1 Sheen 0.04 - - 0.3 0.3 0.04 - - 0.3 0.3 1 Sheen 0.04 0.04 (Silvery / Grey) (Silvery / Grey) 2 Rainbow 0.30 – – 5.0 5.0 0.3 – – 5.0 5.0 2 Rainbow 0.30 0.3 3 Metallic 5.0 - - 50 50 5 - - 50 50 3 Metallic 5.0 5 4 Discontinuous True 50 - - 200 200 50 - - 200 200 4 Discontinuous True 50 50 Oil Colour Oil Colour 5 Continuous True > 200 > 200 5 Continuous True > 200 > 200 Oil Colour Oil Colour

Observing Oil On The Sea Observing Oil On The Sea • A combination of reflected and transmitted light is • A combination of reflected and transmitted light is seen when looking at oil on the sea seen when looking at oil on the sea • With thin layers of oil you see the light reflected • With thin layers of oil you see the light reflected from the sea surface, filtered through a layer of oil from the sea surface, filtered through a layer of oil • With thick layers of oil you see only the surface of • With thick layers of oil you see only the surface of the oil the oil

Appearance Code 1 Sheen (0.04 µ m – 0.3 µ m) The oil layer reflects white light slightly more effectively than the water.

”Rainbow region” (from 0.15 µ m to 3 µ m) Light reflected from both oil/water surface (the sea surface) and oil/air surface (the oil surface) Appearance Code 2 Rainbow Region (0.3 µ m to 5 µ m) Light reflected from both oil/water surface (the sea surface) and oil/air surface (the oil surface)

Appearance Code 3 Metallic (3 µ m to 50 µ m) Majority of light is reflected from oil surface, but a minority passes through oil film and is reflected from sea surface.

Metallic Metallic Rainbow Rainbow Sheen Sheen

Sheen Sheen Metallic Metallic Rainbow Rainbow

Appearance Codes 4 and 5 Discontinuous True Colour and True Colour (50 µ m - < 200 µ m) Light is being reflected from the oil surface rather than from the sea surface

Discontinuous True Oil Colour Discontinuous True Oil Colour and and True Oil Colour True Oil Colour

The True Colour of Oils The True Colour of Oils • Crude oils are black or brown • Crude oils are black or brown • Diesel fuel is nearly colourless • Diesel fuel is nearly colourless • Heavy Fuel Oils are black • Heavy Fuel Oils are black • The observed colour depends on oil film • The observed colour depends on oil film thickness thickness – Optical density of oil Optical density of oil – – Background Background – – Viewing angle Viewing angle –

HEAVY FUEL OI L HEAVY FUEL OI L

THE OI L APPEARANCE CODE THE OI L APPEARANCE CODE CODE APPEARANCE QUANTITY THICKNESS CODE APPEARANCE QUANTITY THICKNESS 3 / km 2 m 3 / km 2 µm m m µ 1 SHEEN 0.04 - - 0.3 0.3 0.04 – – 0.3 0.3 1 SHEEN 0.04 0.04 (SILVERY / GREY) (SILVERY / GREY) 2 RAINBOW 0.3 – – 5.0 5.0 0.3 – – 5.0 5.0 2 RAINBOW 0.3 0.3 3 METALLIC 5.0 – – 50 50 5 – – 50 50 3 METALLIC 5.0 5 4 4 DISCONTINUOUS DISCONTINUOUS 50 50 – – 200 200 50 – 50 – 200 200 TRUE OIL COLOUR TRUE OIL COLOUR 5 5 TRUE COLOUR TRUE COLOUR 200 200 - - > 200 > 200 200 - 200 - > 200 > 200

Appearance Description Appearance Description SHEEN: SI LVERY / GREY – – ALL OI LS WI LL APPEAR THE ALL OI LS WI LL APPEAR THE SHEEN: SI LVERY / GREY SAME SAME RAI NBOW: RAI NBOW: RANGE OF COLOURS – RANGE OF COLOURS – ALL OI LS WI LL APPEAR ALL OI LS WI LL APPEAR THE SAME THE SAME METALLI C: METALLI C: A HOMOGENEOUS COLOUR – A HOMOGENEOUS COLOUR – DEPENDENT ON THE DEPENDENT ON THE LI GHT AND SKY CONDI TI ONS – – A BLUE SKY WI LL A BLUE SKY WI LL LI GHT AND SKY CONDI TI ONS BE MI RRORED I N THE OI L BE MI RRORED I N THE OI L DI SCONTI NUOUS THE BROKEN NATURE OF THE COLOUR, DUE TO DI SCONTI NUOUS THE BROKEN NATURE OF THE COLOUR, DUE TO TRUE COLOUR: THI NNER AREAS WI THI N THE SLI CK I S TRUE COLOUR: THI NNER AREAS WI THI N THE SLI CK I S DESCRI BED AS DI SCONTI NUOUS. THE TRUE DESCRI BED AS DI SCONTI NUOUS. THE TRUE COLOUR OF THE OI L WI LL GRADUALLY COLOUR OF THE OI L WI LL GRADUALLY DOMI NATE. DOMI NATE. TRUE COLOUR: TRUE COLOUR I S OI L SPECI FI C TRUE COLOUR: TRUE COLOUR I S OI L SPECI FI C

“Metallic Metallic” ” a mirror to the sky a mirror to the sky “ Oil layers that look metallic reflect the colour of the sky, but Oil layers that look metallic reflect the colour of the sky, but with some element of oil colour with some element of oil colour

Using the BAOAC to obtain Using the BAOAC to obtain spilled oil volume estimates spilled oil volume estimates � Estimate slick length Estimate slick length � � Estimate slick width Estimate slick width � � Estimate oil coverage as percentage Estimate oil coverage as percentage � � Calculate total slick area Calculate total slick area � � Estimate proportions of different BAOAC Codes Estimate proportions of different BAOAC Codes � � Calculate spilled oil volumes (minimum and maximum) Calculate spilled oil volumes (minimum and maximum) � in each Code area in each Code area � Calculate minimum and maximum spilled oil volume Calculate minimum and maximum spilled oil volume �

AREA MEASUREMENT AREA MEASUREMENT WI DTH WI DTH VI SUAL OBSERVATI ON / MEASUREMENT OF SLAR I MAGE VI SUAL OBSERVATI ON / MEASUREMENT OF SLAR I MAGE 1. LENGTH X WI DTH = AREA OF ‘ ‘I MAGI NARY I MAGI NARY’ ’ RECTANGLE RECTANGLE 1. LENGTH X WI DTH = AREA OF 2. ESTI MATED AREA OF ‘ ‘I MARGI NARY I MARGI NARY’ ’ COVERED WI TH OI L COVERED WI TH OI L 2. ESTI MATED AREA OF AS A PERCENTAGE. AS A PERCENTAGE. 3. CALCULATE THE AREA COVERED WI TH OI L 3. CALCULATE THE AREA COVERED WI TH OI L L L LENGTH X WI DTH X COVERAGE % = AREA LENGTH X WI DTH X COVERAGE % = AREA E E N N COVERAGE COVERAGE G G % % T T H H

OI LED AREA MEASUREMENT OI LED AREA MEASUREMENT AREA ADJUSTMENT AREA ADJUSTMENT (CLEAR WATER) (CLEAR WATER) UV / VI SUAL ASSESSMENT UV / VI SUAL ASSESSMENT (AREAS OF CLEAR WATER WI THI N THE OI L (AREAS OF CLEAR WATER WI THI N THE OI L EXPRESSED AS A PERCENTAGE % ) EXPRESSED AS A PERCENTAGE % ) AREA X ADJUSTMENT % = OI LED AREA AREA X ADJUSTMENT % = OI LED AREA AREAS CLEAR AREAS CLEAR OF OI L OF OI L

PERCENTAGE OF OI LED AREA COVERED BY PERCENTAGE OF OI LED AREA COVERED BY APPEARANCE APPEARANCE VI SUAL ASSESSMENT VI SUAL ASSESSMENT SHEEN (50% ) SHEEN (50% ) METALLI C (5% ) METALLI C (5% ) RAI NBOW (40% ) RAI NBOW (40% ) TRUE COLOUR (5% ) TRUE COLOUR (5% )

VOLUME ESTI MATI ON VOLUME ESTI MATI ON MI NI MUM VOLUME CALCULATI ON MI NI MUM VOLUME CALCULATI ON 1. LENGTH X WI DTH = RECTANGLE AREA 1. LENGTH X WI DTH = RECTANGLE AREA 2. 2. RECTANGLE AREA X PERCENTAGE % COVERAGE = AREA RECTANGLE AREA X PERCENTAGE % COVERAGE = AREA 3. AREA X ‘ ‘CLEAR WATER CLEAR WATER’ ’ ADJUSTMENT % = OI LED AREA ADJUSTMENT % = OI LED AREA 3. AREA X 4. 4. OI LED AREA X I NDI VI DUAL APPEARANCE AREA (EXPRESSED AS A OI LED AREA X I NDI VI DUAL APPEARANCE AREA (EXPRESSED AS A PERCENTAGE OF THE OI LED AREA) = AREA OF OI L APPEARANCE PERCENTAGE OF THE OI LED AREA) = AREA OF OI L APPEARANCE 5. 5. AREA OF OI L APPEARANCE X MI NI MUM THI CKNESS = MI NI MUM AREA OF OI L APPEARANCE X MI NI MUM THI CKNESS = MI NI MUM VOLUME FOR THAT OI L APPEARANCE VOLUME FOR THAT OI L APPEARANCE 6. AS PARA 5 ABOVE FOR EACH APPEARANCE (MI NI MUM VOLUME) 6. AS PARA 5 ABOVE FOR EACH APPEARANCE (MI NI MUM VOLUME) 7. 7. ADD UP ALL THE MAXI MUM VOLUMES FOR ALL THE OI L ADD UP ALL THE MAXI MUM VOLUMES FOR ALL THE OI L APPEARANCES TO FI ND THE ‘ ‘OVERALL OVERALL’ ’ MI NI MUM VOLUME. MI NI MUM VOLUME. APPEARANCES TO FI ND THE