A comparison between hierarchical spatio-temporal models in presence of spatial homogeneous groups: the case of Ozone in the Emilia-Romagna Region

Hierarchical spatio-temporal models permit to estimate many sources of variability. In many environmental problems, different features characterizing spatial locations can be found. Differences in these classifications can show discrepancies either in mean levels or in the spatio-temporal dependence structure. When these characteristics are not included in the model structure, model performances and spatial predictions may lead to poor results. Here, we compare alternative enrichments of the hierarchical spatio-temporal model that consider the presence of groups. Our application concerns Ozone data in the Emilia-Romagna region in which the monitoring sites can be classified according to their relative position with respect to traffic emissions.