Identification of pollen sources affecting Catalonia (South West of Europe) using SILAM model in its adjoint (inverse) mode

Airborne pollen particles can be dispersed into the atmosphere and depending on the meteorological conditions can reach large distances (~103 km) and produce allergic symptoms in a part of the population sensitive to it. In this study, the System for Integrated modeLling of Atmospheric coMposition (SILAM) in its inverse mode (source apportion-ment problem) is applied to determine the main source areas of the episodes that produced high pollen levels ineight aerobiological stations of the Xarxa Aerobiològica de Cata-lunya (Aerobiological Network of Catalonia) during the years 2006, 2007 and 2008. Because of the low local contribution to birch pollen in Catalonia (NE of Spain), it is believed that the occasional birch pollen peaks observed each spring may come from pollen emitted in other European regions. The model SILAM (Sofiev et al, 2006 a) in its adjoint (inverse) mode has been widely applied to study the contribution of long-range transport to the observed pollen peaks in north Europe (Sofiev et al., 2006 b; Siljamo et al., 2008; Veriankaite et al., 2010) and in this work it has been applied to the South of Europe