The western Mediterranean basin as an aged aerosols reservoir. Insights from an old-fashioned but efficient radiotracer

The long-term contemporary 210Pb time series acquired during the period 2004-2011 at two distant sites of different altitude in the Mediterranean basin, El Arenosillo (40 m.a.s.l. in southwestern Spain) and Mt. Cimone (2165 m a.s.l. in northern Italy), are analyzed and compared. In addition, the measurements of PM10 mass concentrations collected at the same time and the corresponding 210Pb/PM10 ratio at the two sites are considered to gain better insights into the origin and size of the particles. Three statistical trajectory methods are applied to identify and characterize the 210Pb source regions at the two sites. The three methods yield similar outcomes in the source identification, which strengthens the robustness of our results. In addition to the importance of the transport from areas of continental Europe, this study highlights the relevant role of the Mediterranean Sea as an important 210Pb reservoir layer associated to the aged air masses that accumulate in the western Mediterranean basin. The analysis of the sources points out the relevant influence of northern Africa to 210Pb increases at both sites as well, even though the most intensive episodes are not of Saharan origin. This work is the first time that 210Pb measurements at two distant sampling sites of different heights are simultaneously analyzed, allowing the identification and characterization of common sources with impact over the whole region.

BRATTICH Erika;  HERNANDEZ CEBALLOS Miguel Angel;  ORZA Jose Antonio;  BOLIVAR Juan Pedro;  TOSITTI Laura; 

2017-01-13

PERGAMON-ELSEVIER SCIENCE LTD

JRC100538

1352-2310,   

http://www.sciencedirect.com/science/article/pii/S1352231016305416,    https://publications.jrc.ec.europa.eu/repository/handle/JRC100538,   

10.1016/j.atmosenv.2016.07.022,