Exploring wind direction and SO${}_2$ concentration by circular-linear density estimation

Abstract

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 SO${}_2$ 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.