LEO: Combination of a Plume and Grid Model in the Netherlands

We present the chemistry transport model LEO: a hybrid model, which combines the Eulerian grid model LOTOS-EUROS with the Gaussian plume model OPS. LEO is a new model under development in the Netherlands, which combines high resolution plume calculations around sources with large-scale transport and chemistry from a Eulerian grid model. In this way, we combine the best of both worlds into a new state-of-the-art model. The aim of LEO is to have a new calculation tool available in the Netherlands at a high resolution (typically 1 x 1 km(2)), which can (among others) deliver data input for the yearly produced maps of concentrations and deposition over the Netherlands. In the presentation a brief overview of the LEO model is given, and results of calculations are presented for calculating annual averaged concentrations of pollutants and deposition of acidifying and eutrophying components over the Netherlands. Furthermore, preliminary results are shown for LEO in its Plume-in-Grid (PinG) configuration, i.e., the transport of the mass released from a number of point sources is initially calculated with a plume description, after which the mass of the plumes is dumped into the grid. We will illustrate the performance of LEO by analysing existing multi source situations for ammonia with high time resolution measurements of ammonia.