Testing interpolation and filtering techniques in connection with a semi-Lagrangian method

In air pollution models, semi-Lagrangian methods are often used to solve the advective part of the corresponding model equations. Interpolation is an essential part of these methods. In this paper, five different interpolation methods will be discussed and results of numerical experiments will be presented. To keep the concentration field non-negative, filtering techniques are used. A monotone interpolation method is also examined.