Environmental and Ecological Statistics

, Volume 16, Issue 4, pp 515–529 | Cite as

A simple non-separable, non-stationary spatiotemporal model for ozone

  • Francesca Bruno
  • Peter Guttorp
  • Paul D. Sampson
  • Daniela Cocchi
Article

Abstract

The past two decades have witnessed an increasing interest in the use of space-time models for a wide range of environmental problems. The fundamental tool used to embody both the temporal and spatial components of the phenomenon in question is the covariance model. The empirical estimation of space-time covariance models can prove highly complex if simplifying assumptions are not employed. For this reason, many studies assume both spatiotemporal stationarity, and the separability of spatial and temporal components. This second assumption is often unrealistic from the empirical point of view. This paper proposes the use of a model in which non-separability arises from temporal non-stationarity. The model is used to analyze tropospheric ozone data from the Emilia-Romagna Region of Italy.

Keywords

Spatiotemporal process Temporal non-stationarity Non-separability Deformation Tropospheric ozone 

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Copyright information

© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  • Francesca Bruno
    • 1
  • Peter Guttorp
    • 2
  • Paul D. Sampson
    • 2
  • Daniela Cocchi
    • 1
  1. 1.Department of Statistics P. FortunatiUniversity of BolognaBolognaItaly
  2. 2.Department of StatisticsUniversity of WashingtonWashingtonUSA

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