Updates of the atmospheric dispersion models inside the Local Scale Model Chain of RODOS regarding particles

Abstract

New schemes for calculating particles dry and wet deposition have been implemented in the Local Scale Model Chain of RODOS in the frame of Work Package 4 of project PREPARE. Care has been taken not to increase computational times and at the same time, simulations performed with previous deposition schemes to be reproducible. The new schemes take into account particles properties: size and density. Important assumptions adopted so far are that the particles properties are the same for all nuclides and that the properties remain constant during all times of release and dispersion. All formulations adopted for calculating dry and wet deposition coefficients for particles depending on their properties are widely used in the scientific literature. The first tests that have been performed show that the new particles deposition schemes behave as expected and deposition is scaled depending on the size and the density of the particles. The calculated deposition patterns for fine particles with the new scheme are very similar to those calculated by the previous scheme. For larger particles, the differences in comparison to results with the previous deposition scheme justify the implementation of the new scheme in JRODOS.