Modelling activities constrained by Target Selective Inhibitor Library observations need to be focused on aerosol cloud-mediated climate in the Baltic Region. This ideally should include: • Treatment of biogenic and carbonaceous aerosols. Summarising the results presented above, it can be concluded that there is clear observational evidence for an anthropogenic influence on aerosol cloud-mediated processes

over Europe. The effects show individual characteristics for different atmospheric circulation patterns. The next steps need to combine atmospheric modelling and different observations synthesised in more detail, including the latest achievements from field studies aiming to analyse the European aerosol system (Kulmala et al. 2011). “
“The climatic features of a particular region depend primarily on latitude, land-sea interactions and the annual cycle (seasons), whereas intra-seasonal variations of climate are determined mostly by atmospheric circulation. In temperate climates, prolonged ‘steady states’ of atmospheric conditions usually give rise to extreme events such as floods, droughts, thaws, and frosts. In boreal zones of excessive moisture, extreme droughts are not a very common phenomenon (Lloyd-Hughes & Saunders 2002); all four categories of drought (Mishra & Singh 2010) have nevertheless been identified. First of all, droughts have a major impact on agriculture as well as on the increasing number of forest

fires and the decrease in river runoff (Hisdal & Tallaksen 2003). Moreover, PR-171 price ever droughts can seriously affect the regional economy, human social life and wildlife (Thorsteinsson and Björnsson, 2011 and Rimkus et al., 2013). Recent studies have indicated that the number of droughts has not been increasing in northern Europe (Bordi et al. 2009); nonetheless, droughts are still expected to be common in the future (Kjellström et al. 2007). Every regional scale of drought has its own, unique, developing scenario because of the very complex nature of droughts. Lack of precipitation is well-known as the main factor contributing to drought

occurrence, while other factors either have a too ‘long memory’, such as soil moisture in deeper layers, or large spatial variability in land use and vegetation cover, or very special preconditions such as snow water equivalent, the rate of snow melt and the thickness of frozen soil. Earlier studies showed that there is no typical chain of processes linked to summer drought occurrence either in northern Europe (Parry et al., 2010 and Kingston et al., 2013) or in northern North America (Girardin et al., 2006 and Cook et al., 2011). However, some circulation indices are still useful diagnostic tools for the large-scale atmospheric circulation impact on regional hydro-thermal anomalies (Zveryaev, 2004 and Samaniego and Bardossy, 2007, Ignacio et al. 2008, Parry et al. 2010).