Urban Photochemical Pollution in the Iberian Peninsula: Lisbon and Barcelona Airsheds

Abstract

Numerical simulations with photochemical transport models were independently performed for two domains situated in the Iberian Peninsula covering the Lisbon and Barcelona airsheds. Although the days chosen for simulation of the two cities are not the same, the synoptic situations in both cases, known as typical summertime situations, were similar, which allowed the development of typical mesoscale circulations, such as sea breezes and mountain and valley winds dominated by the Azores anticyclone. Emission inventories for the two areas were developed. The O 3 concentrations recorded in both cities have a similar level. Nevertheless, O x values in Barcelona are higher than in Lisbon, which may, at a first glance, indicate an apparently more oxidant atmosphere in Barcelona. Photochemical modeling for the two cities has shown that the behavior of the circulatory patterns in both urban areas is rather different, which mainly has to do with the different strengths of the sea breeze and the topography, inducing an important offshore vertical layered dimension of pollutant transport in Barcelona versus an important inland horizontal transport in Lisbon.

Application of TAPM to predict photochemical air pollution over Portugal

“…Concentration patterns show that there is a potential advection and transport of the pollutants emitted from the major urban centers (Porto and Lisbon) to the coast and to some inland parts of Portugal. This scenario confirms other mesoscale meteorological simulations performed in this region by other authors [11][12][13]. Observed and simulated hourly maximum ozone values for different types or air quality monitoring sites.…”

Air quality assessment for Portugal

“…Unfortunately, according to the land use map, these areas correspond to high-density vegetation and forest areas. These ozone concentration patterns were already foreseen in previous mesoscale modelling studies (Barros et al, 2003;Borrego et al, 2000), where the ozone precursors transport from the urban areas of Porto and Lisbon to the south and interior part of Portugal (by the N-NW dominant winds) is clear and significant.…”

“…Recent works (Hogrefe et al, 2001) emphasize the importance of policy analysis on a "climatological" basis rather than of focusing on a single critical episode; this approach allows to better evaluate the model performances and to quantify policies effects with respect to long-term air quality standards. Several ozone modelling studies were already performed for Portugal, in β-mesoscale domains and during some specific and episode days (e.g., Barros et al, 2003;Borrego et al, 2000). Large-scale simulations including Portugal have also been done, but with a coarse grid resolution (Coutinho and Borrego, 1991).…”

Are the Pyrenees a barrier for the transport of birch (Betula) pollen from Central Europe to the Iberian Peninsula?

“…The path through the Mediterranean Sea could be related with the sea breeze influence, which is relevant in the Iberian Mediterranean coastal regions, especially in spring and summer. Besides, the sea breeze is stronger in the Barcelona area, where the Bellaterra station is located, because of the development of the upslope winds on the southern slopes of the coastal mountain range, which contribute to the reinforcement of the general onshore flow (Barros et al, 2003) and the production of Betula peaks when these air-masses are pollen loaded. The path through Les Alberes region pass was also traced by the MM5 mesoscale model to describe the LRT transport of Fagus pollen from NE France and SW Germany to Catalonia (Belmonte et al, 2008).…”