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Pour Point
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Pour point is the lowest temperature at which an oil will flow at a specific rate under specified conditions. It is roughly equivalent to melting point for pure substances, but because oil is a mixture of compounds, pour point is difficult to measure precisely, and may vary somewhat from sample to sample. ADIOS2 reports the initial pour point of the oil, and warns you if the spill is in water temperature below the pour point, but will still attempt to predict the weathering of the oil slick. The model does this for two reasons. First, there is uncertainty in the actual pour point value, and second, oil that is initially above the water temperature will take some time to cool down to the water temperature. However, you should be aware that the answers from such a scenario may be unreliable.
Technical Details
ADIOS2 does not use pour point value in its weathering algorithms except when providing you with a warning message if the water temperature is below pour point. It is important to note that pour point increases as the oil weathers. ADIOS2 does not model this. However, the interested user can refer to Mackay et. al (1983) for a formula to compute this change.
References
Mackay, D., W. Stiver, and P.A. Tebeau.1983. Testing of Crude Oils for Petroleum Products for Environmental Purposes, Proc. of the 1983 International Oil Spill Conference, American Petroleum Institute, Washington, D.C., pp. 331-337.
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BackLast updated October 31, 2000
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