A Spatio-Temporal Model for Mexico City Ozone Levels
Gabriel Huerta, Bruno Sansó, Jonathan R. Stroud
University of New Mexico, UC-Santa Cruz, University of Pennsylvania
We consider hourly readings of ozone concentrations over Mexico City and propose a model
for spatial as well as temporal interpolation and prediction. The model is based on regressing
the observed readings on air temperature. Two harmonic components are added to account
for the main periodicities that ozone presents during a given day and that are not explained
by the temperature covariate. The model incorporates spatial covariance structure for the
observations and the parameters that define the harmonic components. Using the dynamic linear
model framework, we show how to compute smoothed means and predictive values for ozone.
We illustrate the methodology on data from September, 1997.
The manuscript is available in PDF format.