SCIPUFF Dispersion Model
SCIPUFF (Second-order Closure Integrated Puff) model is a Lagrangian puff dispersion model using Gaussian puffs to represent an arbitrary, three-dimensional time-dependent concentration. The diffusion parameterization is based on turbulence closure theory, which gives a prediction of the dispersion rate in terms of the measurable turbulent velocity statistics of the wind field. This generalized approach provides a unified parameterization for modelling dispersion at all ranges from laboratory to continental scales. The explicit representation of diffusion in terms of velocity statistics also provides a rational basis for the assessment of time-averaging effects.
In addition to the average concentration, the turbulence closure model also provides a prediction of the statistical variance in the concentration field resulting from the random fluctuations in the wind field. Using a simple shape assumption for the probability distribution function (pdf), the mean and variance are used to generate a quantitative probability prediction.
- Continuous, instantaneous, moving and stack sources
- Gaseous and particulate materials
- Buoyant and non-buoyant releases
- Complex terrain effects and mass-consistent wind-field adjustment
- Dry deposition
- Wet deposition and gravitational settling of particles
- Linear decay of released materials
- Short and long range transport
- Fixed winds, surface or profile observations or gridded meteorological input accepted
- Time-history concentration sampling capability (i.e., receptors)
- Provides estimates of the uncertainty in the concentration field
- Performs accurate treatment of wind shear
- Merges puffs in addition to splitting them using an efficient adaptive multi-grid scheme.
- Uses an efficient adaptive time-stepping scheme.
- Utilizes static puffs near the source to reduce computation time.
- Flexible output displays color contour plots of concentration and probabilities of exceeding user-specified concentrations.
SCIPUFF Public Domain Version - EPA Alternative Model
SCIPUFF has been validated against a number of classical laboratory and field experiments, demonstrating its usefulness for general atmospheric dispersion applications. It has been recommended as an alternative model by the EPA which can be used on a case-by-case basis for regulatory applications.
In 2000, a public domain version of SCIPUFF was submitted to the EPA by Titan Corporation as an EPA Alternative Model. All defense related features are removed. The link to download this version of SCIPUFF, as mentioned in the EPA SCIPUFF Model Overview, is now defunct. As a courtesy, Sage Management makes available for download this public domain version of SCIPUFF, known as PC-SCIPUFF Model (Version 1.2PD31.5) 7/18/2000.
Contact SCIPUFF Model Developers
15 Roszel Road, Suite 102
Princeton, NJ 08540
Phone: (609) 452-2950 x103
Fax: (609) 452-2856
Sykes, R. I., C. P. Cerasoli and D. S. Henn (1999). The representation of dynamic flow effects in a Lagrangian puff dispersion model, J. Haz. Mat., 64, 223-247.
Sykes, R. I., S. F. Parker, D. S. Henn, C. P. Cerasoli and L. P. Santos (1998). PC-SCIPUFF Version 1.1PD.1 Technical Documentation. ARAP Report No. 718. Titan Corporation, Titan Research & Technology Division, ARAP Group, P.O. Box 2229, Princeton, NJ, 08543-2229.
Sykes, R. I. and R. S. Gabruk (1997). A second-order closure model for the effect of averaging time on turbulent plume dispersion, J. Appl. Met., 36, 165-184.
Sykes, R. I., D. S. Henn, S. F. Parker and R. S. Gabruk (1996). SCIPUFF - A generalized hazard dispersion model. Ninth Joint Conference on the Applications of Air Pollution Meteorology with A&WMA, American Met. Soc.
Sykes, R. I. and D. S. Henn (1995). Representation of velocity gradient effects in a Gaussian puff model. J. Appl. Met., 34, 2715-2723.
Sykes, R. I., S. F. Parker, D. S. Henn and W. S. Lewellen (1993). Numerical simulation of ANATEX tracer data using a turbulence closure model for long-range dispersion, J. Appl. Met., 32, 929-947.