Resumen
Graphical representations for the vertical plume spread parameter, sz require digitisation for implementation in numerical calculations of plume spread. Current algebraic representation for these curves (developed from the original Pasquill-Gifford-Turner curves) centres on determining a "best-fit" regression together with other empirical evidence. Here an observationally validated conceptual model based on turbulent mixing theory is proposed for the quantification of the PGT curves for neutral and stable conditions.