Regional and intercontinental modelling - Air Pollution Modeling and Its Application - page 123

2. Model Description

The LOTOS-EUROS model (Schaap et al., 2008) is used to calculate the PM10
distributions over Europe for 2005. The LOTOS-EUROS model is a 3D chemistry
transport model aimed to simulate air pollution in the lower troposphere. In the
vertical the model has four layers up to 3.5 km following the dynamic mixing
layer approach. The horizontal resolution used here is 0.5° × 0.25°. The model is
suitable to calculate the transport of primary (combustion) particles (EC, OC), sea
salt and secondary inorganic aerosols (SIA: SO4, NO3, NH4). In this study, we
incorporated the description of crustal material for the following emission sources:
wind-abrasion, resuspension by traffic, and resuspension by agricultural-activities
(see below). In addition, the inflow of desert dust originating from large deserts
residing outside the LOTOS-EUROS model domain is included by applying
concentration data of the TM5 global transport model at all boundaries.

2.1. Wind-blown dust emission

The emission of wind-blown dust (wind-induced abrasion) was included following
the work of Marticorena and Bergametti (1995, 1997), Gomes et al. (2003) and
Alfaro et al. (2004). The applied methods are based on well-know relations for
saltation induced dust production in desert area and take into account information
on soil texture.

2.2. Resuspension by traffic

A pragmatic approach is followed to calculate of traffic related resuspension
emission with the LOTOS-EUROS model:
∑∑

F = C C EF D ,

trs c lim rs veh , road veh , road

veh road

The method is based upon a vehicle driven kilometre map (D veh,road ) over
Europe, typified for light duty (LDV) and heavy duty (HDV) traffic and three road
type classes (rural roads, urban roads and highways), with corresponding emission
factors (EF veh,road ). The first order estimates for the applied emission factors for
PM 2.5-10 , based upon literature (Ketzel et al., 2007; Thorpe et al., 2007 a.o.) are
listed in Table 1 . C clim and C rs are factors to account for variability of traffic resus-
pension due to the variability of climate conditions (parameterised using soil water
content) and road sanding activities. During precipitation traffic resuspension is
neglected.