An Application of a Diagnostic Wind Model to Describe Atmospheric Transport

In this paper a diagnostic model is used to reconstruct the wind field on the basis of measurements: An initial wind field generated from available sparse measured data is corrected to satisfy mass conservation by solving a three-dimensional elliptic differential equation. The actual orography is taken into account by transforming this equation to a terrain-following coordinate system. For the solution of the transformed equation a fully vectorized fast elliptic solver is applied. By the aid of the obtained wind fields air parcel trajectories may be calculated to elucidate the prevailing atmospheric transport mechanisms. As an example, wind fields and air parcel trajectories are presented for the Athens basin. The results confirm the features of the sea breeze circulation hinted at by observations and by previous calculations. The identified air movements are discussed in view of the elevated pollution levels in Athens.