Impact of air masses on the distribution of 210Pb in the southeast of Iberian Peninsula air.

The current research has been developed in the southern of the Iberian Peninsula in order to better understand the atmospheric processes and also the influence of the air masses origin and pathways in the transport of 210Pb-aerosols in the atmosphere. Simultaneous measurements of the radionuclides 7Be and 210Pb on airborne have been routinely carried out at Granada (Spain 37.177N, 3.598 W, 687 m a.s.l.) from 2010 to 2014. The long term monitoring evolution on 210Pb is discussed in this study and also the useful ratio 7Be/210Pb. The maximum monthly activity concentration for 210Pb at ground level in Granada was detected during summer and early autumn (September), whereas minimum activity was measured in the winter. The monthly mean activity concentration for 210Pb was 617.8 ± 33.0 µBq·m-3. The results show that the annual average 210Pb concentrations in samples collected during the same period were almost constant. The lowest activity concentration for 210Pb are associated with maritime air masses coming from Atlantic and Norwest of Spain, while the highest activity concentrations for this radiotracers were positively correlated with the arrival of mineral dust linked to continental air masses coming from Mediterranean, Africa and Local area. The concentrations values show a nice agreement with the relevant reported results.

A cluster analysis of back trajectories to study the behaviour of radioactive aerosols in the south-east of Spain.

This research is focused on the study of the influence of the air masses together with the local meteorological fluctuations on the amount of radioactive elements in aerosols at surface air of the southeastern of Iberian Peninsula. The radioactivity in aerosols has been determined by measuring the concentration activity of Gross ß and (7)Be from January 4(th), 2011 to December 31(s)(t), 2013. The activity concentration (Bq/m(3)) of gross beta was measured by α/ß Low-Level counter, whereas the activity concentration of (7)Be (Bq/m(3)) was detected by gamma spectrometry (Eγ = 477.6 KeV, Yield = 10.42%). The air mass origings have been set using k-means clustering analysis of daily 72-h kinematic 3D backward trajectories at 500 m, 1500 m and 3000 m of altitude. Finally, a multiple Regression Analysis (MRA) have been carried out in order to determine the influence of the origins and trajectories of the air masses and local meteorology variations on the evolution of Gross ß and (7)Be activity concentration. In conclusion, the results of the current research demonstrate that the re-suspended mineral dust from Northern Africa transported by Mediterranean air masses at low altitude (500 m) and African air masses at high altitude (3000 m) increases the radioactivity concentration in aerosols at the surface atmosphere. In addition, the opposite influence of the Saharan intrusions at 1500 m of altitude on the behaviour of (7)Be aerosols deserves special attention.