On the Relationship Between Synoptic Scale Parameters and Pasquill Stability Classes for the Purposes of Air Pollution Modeling

Quite often, for the tasks connected with environmental impact assessment it is necessary to estimate pollutant concentrations on the basis of standard meteorological data such as sunshine, cloud amount, and wind velocity using the Pasquill stability classes. They are usually determined from the atmospheric characteristics estimated near the ground surface using a table classification with 10 m wind velocity and insolation intensity (or cloud cover at night). These meteorological data are not allways available and they are difficult for prognostication. For the purposes of the prognostical estimation of the atmospheric diffusion in case of emergency releases when regulatory type models are used it is useful to find the relation between the synoptic scale parameters obtained from the numerical weather prediction and the Pasquill stability classes.