Evidences of different meteorological patterns governing 7Be and 210Pb surface levels in southern Iberian Peninsula

7Be, 210Pb and PM10 levels in surface air have been simultaneously measured at two sampling sites in southern Iberian Peninsula during two years. Each site covers one different meteorological area of the Guadalquivir valley, from the mouth (Huelva) to the middle point (Cordoba). The objective of the present paper was to analyze the spatial variability of both natural radionuclides, and to identify and characterize the meteorological patterns associated with similar and different surface concentration levels in this complex region. Concentrations were similar in both sampling sites. 7Be was from 0.6 to 15.5 mBq m-3 in Huelva, and from 1.2 to 13.3 mBq m-3 in Córdoba, 210Pb activity concentrations were between 0.04 and 2.30 mBq m-3 in Huelva, and between 0.03 and 1.2 mBq m-3 in Cordoba, while the PM10 concentrations were found to be in the 5.1-81.3 µg m-3 range in Huelva, and 8.2-76.3 µg m-3 in Cordoba respectively. A linear regression analysis indicated more regional variability for 210Pb than for 7Be between simultaneous measurements. Principal components analysis (PCA) was applied to the datasets and the results revealed that aerosol behavior was mainly represented by two components, which explain 82 % of total variance. The analysis of surface measurements and meteorological parameters revealed that componetF1 grouped sampling periods in which the influence of similar meteorological conditions over the region lead to similar 7Be, 210Pb and PM10 concentration levels in both sampling sites. On the contrary, component F2 detached the 7Be, 210Pb and PM10 concentration levels between monitoring sites, and the meteorological analysis showed how this component is associated with the development of different mesoscale circulations in each part of the valley. The identification of sampling periods characterized by differences in surface concentrations and wind patterns between stations suggests that the valley could not be taken as one single unit for certain meteorological scenarios. These results evidence how the understanding of wind characteristics within a complex terrain provide some essential knowledge in the regionalization and/or optimization of monitoring networks.

GUTIERREZ SAN MIGUEL Enrique;  HERNANDEZ CEBALLOS Miguel Angel;  GARCIA MOZO Herminia;  BOLIVAR Juan Pedro; 

2019-01-16

ELSEVIER SCI LTD

JRC114091

0265-931X (online),   

https://publications.jrc.ec.europa.eu/repository/handle/JRC114091,   

10.1016/j.jenvrad.2018.12.007 (online),