Exploring wind direction and SO2 concentration by circular–linear density estimation

  • E. García-PortuguésEmail author
  • R. M. Crujeiras
  • W. González-Manteiga
Original Paper


The study of environmental problems usually requires the description of variables with different nature and the assessment of relations between them. In this work, an algorithm for flexible estimation of the joint density for a circular–linear variable is proposed. The method is applied for exploring the relation between wind direction and SO2 concentration in a monitoring station close to a power plant located in Galicia (NW–Spain), in order to compare the effectiveness of precautionary measures for pollutants reduction in two different years.


Circular distributions Circular kernel estimation Circular–linear data Copula 



The authors acknowledge the support of Project MTM2008–03010, from the Spanish Ministry of Science and Innovation and Project 10MDS207015PR from Dirección Xeral de I+D, Xunta de Galicia. Work of E. García-Portugués has been supported by FPU grant AP2010–0957 from the Spanish Ministry of Education. We also thank the referee and the Associate Editor for providing constructive comments and help in improving this paper.


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Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  • E. García-Portugués
    • 1
    Email author
  • R. M. Crujeiras
    • 1
  • W. González-Manteiga
    • 1
  1. 1.Department of Statistics and Operations Research, Faculty of MathematicsUniversity of Santiago de CompostelaSantiago de CompostelaSpain

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