Characterization of a long range transport pollution episode affecting PM in SW Spain

Abstract

A multidisciplinary study on aerosol characterization was performed at the regional background monitoring station of El Arenosillo, in SW Spain, between 28 June and 5 July 2006. The main aim of the Arenosillo aerosol measurement campaign 2006 was to compare the results of aerosol characterization obtained by different groups by measuring physical and chemical parameters using optical methods and in situ sampling. The campaign coincided with a long-range transport episode from Western Iberia, passing through the Gulf of Cadiz and the Straits of Gibraltar towards the study area. The results of the variability of PM levels and chemical composition of PM10, PM2.5 and PM1 at El Arenosillo and at three nearby regional and urban background sites were interpreted. Mean levels measured during the campaign reached 23, 15 and 12 microg m(-3) for PM10, PM2.5 and PM1, respectively, at El Arenosillo. PM during the Arenosillo campaign 2006 was dominated by the secondary inorganic aerosols (SIA, 24, 38 and 39% of PM10, PM2.5 and PM1 mass), carbonaceous aerosols (17, 21 and 23% of the mass), crustal material (13, 9 and 4%), and sea spray (10, 5 and 1%). These values are within the usual range of regional background sites of Southern Spain with the exception of the relatively low crustal load and the high SIA levels. Two major PM episodes were differentiated. The first one was characterized by high levels of Bi, As, Pb, Se, P and Zn, which are the main tracers of the industrial emissions near the town of Huelva. High concentrations of these elements were also recorded at the nearby sites. In the second episode, maximum levels of SO4(2-), V and coarse Cu as well as the bulk mass of PM1 were determined, tracing the polluted air mass transport from Western Iberia through the Straits of Gibraltar. These results underline the importance of the influence of long-range transport of pollutants on the levels and composition of regional background PM in SW Iberia, where local emissions may also play a role.

Variability of aerosol, gaseous pollutants and meteorological characteristics associated with changes in air mass origin at the SW Atlantic coast of Iberia

“…In the marine boundary layer (MBL) sulfur compounds are quite common (Charlson et al, 1987;Zorn et al, 2008) as the ocean is a large source for atmospheric sulfur (Barnes et al, 2006). In addition, shipping emissions of marine transport in the Strait of Gibraltar play an important role as reported by Pey et al (2008). Therefore, "sulfate" is the most abundant species of the "Marine" submicron non-refractory aerosol with a fraction of 54 % (0.91 ± 0.43 µg m −3 ).…”

“…This offers the advantage to achieve a better understanding of the characteristics, sources and processes, as typical summer features in this part of Southern Europe are reduced: enhanced photochemistry or recirculation periods that typically occur in spring and summer seasons in this part of Southern Europe (Pey et al, 2008) would contribute to a more complex study scenario.…”

“…The Atlantic Ocean itself has relatively low levels of pollutants, however there are shipping emissions from heavy ship traffic in the Strait of Gibraltar (Pey et al, 2008). Huelva is a highly industrialized town with three large chemical estates…”

“…In addition, particularly in Southern Europe, the season plays an important role. In the summer months African dust outbreaks, re-circulation of air masses, strong photochemistry and long range transport from NW Europe or Western Iberia (Sanchez de la Campa et al, 2007;Pey et al, 2008) affect the atmospheric composition and levels. The SW of Spain lies next to the Atlantic Ocean and the Strait of Gibraltar, a major ship route.…”

On the sub-micron aerosol size distribution in a coastal-rural site at El Arenosillo Station (SW – Spain)

“…the sea-land breeze) is very typical in coastal areas during spring and summer and plays an important role in transporting air pollution from and towards urban areas, (Ma and Lyons, 2003;Sorribas et al, 2007;Pey et al, 2008;Adame et al, 2010a;Wright et al, 2010). Given that El Arenosillo is located in a coastal rural site, the influence of the regional aerosol transport on the background particle level is analysed in this section.…”