CANARINA:
DISPER:
SOLUTIONS: DISPER
COMMANDS:
ALGORITHMS:
EMISSIONS:
GRAPHS:

Downwind and Crosswind Distances The model uses a Cartesian receptor network. All receptor points are converted to Cartesian (X,Y) coordinates prior to performing the dispersion calculations. In the Cartesian coordinate system, the X axis is positive to the east of the userspecified origin and the Y axis is positive to the north. The user must define the location of each source with respect to the origin of the grid using Cartesian coordinates. If the X and Y coordinates of the source are X(S) and Y(S), the downwind distance x to the receptor, along the direction of plume travel, is given by: x=[X(R)X(S)]sin(WD)[Y(R)Y(S)]cos(WD) (2) where WD is the direction from which the wind is blowing. The downwind distance is used in calculating the distancedependent plume rise and the dispersion parameters. The crosswind distance y to the receptor from the plume centerline is given by: y=[X(R)X(S)]cos(WD)[Y(R)Y(S)]sin(WD) (3) Wind Speed Profile The wind power law is used to adjust the observed wind speed, u_{ref}, from a reference measurement height, z_{ref}, to the stack or release height, h_{s}. The stack height wind speed, u_{s}, is used in the Gaussian plume equation. The power law equation is of the form: u_{s}=u_{ref}(h_{s}/z_{ref})^{p} (4) where p is the wind profile exponent. Values of p may be provided by the user as a function of stability category and wind speed class. Default values are as follows:
The stack height wind speed, u_{s}, is not allowed to be less than 1.0 m/s. Algorithms I  Algorithms II  Algorithms III  Algorithms IV  Algorithms V  Algorithms VI  Algorithms VII  Algorithms VIII  Algorithms IX  Algorithms X
Air pollution map (XYPlane) produced by continuous discharge in time (three stacks). The red colour represents high pollutant concentrations. Wind: SE (135 degrees).
Air pollution map (XYPlane) produced by continuous discharge in time. The fucshia lines represents a stacks in the XYPlane. The red colour represents high pollutant concentrations. Winds: E (90 dregrees) and 70 degrees.
