San Miguel E G, Hernández-Ceballos M A, García-Mozo H, Bolívar J P
Department of Integrated Sciences, Area of Applied Physics, University of Huelva, 21071, Huelva, Spain; Research Center on Natural Resources, Health and the Environment (RENSMA), University of Huelva, 21071, Huelva, Spain.
European Commission, Joint Research Centre (JRC), Ispra, Italy.
J Environ Radioact. 2019 Mar;198:1-10. doi: 10.1016/j.jenvrad.2018.12.007. Epub 2018 Dec 15.
Be, Pb and PM levels in surface air have been simultaneously measured at two sampling sites in the southern Iberian Peninsula for a period of 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 study is to analyse the spatial variability of both natural radionuclides, and to identify and characterise the meteorological patterns associated with similar and different surface concentration levels in this complex region. Concentrations are similar in both sampling sites. Be level is in the 0.6-15.5 mBq m range in Huelva and 1.2-13.3 mBq m in Córdoba, Pb activity concentrations are between 0.04 and 2.30 mBq m in Huelva, and between 0.03 and 1.2 mBq m in Cordoba, and PM concentrations are found to be in the 5.1-81.3 μg m range in Huelva, and 8.2-76.3 μg m in Cordoba, respectively. A linear regression analysis indicates more regional variability for Pb than for Be between simultaneous measurements. Principal components analysis (PCA) is applied to the datasets and the results reveal that aerosol behaviour is mainly represented by two components, which explain 82% of the total variance. The analysis of surface measurements and meteorological parameters revealed that component F1 groups sampling periods in which the influence of similar meteorological conditions over the region lead to similar Be, Pb and PM concentration levels in both sampling sites. On the other hand, component F2 detaches the Be, Pb and PM concentration levels between monitoring sites, and the meteorological analysis shows how surface concentrations within this component are associated with the development of different mesoscale circulations in each part of the valley. The identification of sampling periods characterised by differences in surface concentrations and wind patterns between stations suggests that the valley could not be considered 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.
在伊比利亚半岛南部的两个采样点对地表空气中的铍（Be）、铅（Pb）和颗粒物（PM）水平进行了为期两年的同步测量。每个采样点覆盖瓜达尔基维尔河谷一个不同的气象区域，从河口（韦尔瓦）到中点（科尔多瓦）。本研究的目的是分析这两种天然放射性核素的空间变异性，并识别和表征与该复杂区域中相似和不同地表浓度水平相关的气象模式。两个采样点的浓度相似。韦尔瓦的铍水平在0.6 - 15.5 毫贝克勒尔每立方米范围内，科尔多瓦为1.2 - 13.3 毫贝克勒尔每立方米；韦尔瓦的铅活度浓度在0.04 至2.30 毫贝克勒尔每立方米之间，科尔多瓦在0.03 至1.2 毫贝克勒尔每立方米之间；韦尔瓦的颗粒物浓度在5.1 - 81.3 微克每立方米范围内，科尔多瓦在8.2 - 76.3 微克每立方米范围内。线性回归分析表明，同步测量期间铅的区域变异性比铍更大。对数据集应用主成分分析（PCA），结果显示气溶胶行为主要由两个成分表征，这两个成分解释了总方差的82%。对地表测量数据和气象参数的分析表明，成分F1 对采样期进行了分组，在这些采样期中，该区域相似气象条件的影响导致两个采样点的铍、铅和颗粒物浓度水平相似。另一方面，成分F2 区分了监测点之间的铍、铅和颗粒物浓度水平，气象分析表明该成分内的地表浓度与河谷各部分不同中尺度环流的发展相关。对各站点之间地表浓度和风型存在差异的采样期的识别表明，对于某些气象情景，该河谷不能被视为一个单一单元。这些结果证明了对复杂地形中风特征的理解如何为监测网络的区域划分和/或优化提供一些重要知识。
