BREEZE SCIPUFF
BREEZE SCIPUFF is a time-dependent Gaussian puff model developed by Titan's ARAP Group that employs second-order closure turbulence modeling techniques to relate the dispersion rate to velocity fluctuation statistics.
BREEZE developers created a Graphical User Interface (GUI) that include a GIS, user-friendly data entry forms, parameter range checks, 3D visualization, reporting, and more. In addition to the capability of running the system on a standard Windows® desktop PC, BREEZE developed a system that runs the SCIPUFF model on a LINUX cluster.
SCIPUFF Overview
SCIPUFF is a Lagrangian puff dispersion model that uses a collection of Gaussian puffs to represent an arbitrary, three-dimensional, time-dependent concentration field. The turbulent diffusion parameterization is based on modern turbulence closure theory, specifically the second-order closure model of Donaldson (1973) and Lewellen (1977), which provides a direct relationship between the predicted dispersion rates and the measurable turbulent velocity statistics of the wind field. In addition to the average concentration value, the closure model also provides a prediction of the statistical variance in the concentration field resulting from the random fluctuations in the wind field. The closure approach also provides a direct representation for the effect of averaging time (Sykes and Gabruk, 1997).
The general features of SCIPUFF are as follows:
- Continuous, instantaneous, moving and stack sources
- Gaseous and particulate materials
- Buoyant and non-buoyant releases
- Flat and complex terrain
- 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
- Puff sampling capability (i.e., receptors)
In addition, SCIPUFF also:
- 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.
Donaldson, C. du P., 1973. Atmospheric turbulence and the dispersal of atmospheric pollutants, AMS Workshop on Micrometeorology, D.A. Haugen (Ed.). Science Press, Boston. pp. 313-390.
Lewellen, W.S., 1977. Use of invariant modeling, Handbook of Turbulence, W. Frost and T.H. Moulden (Eds.). Plenum Press. pp. 237-280.
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. Meteor., 36: 165-184.