Articles | Volume 8, issue 10
Atmos. Meas. Tech., 8, 4487–4505, 2015
Atmos. Meas. Tech., 8, 4487–4505, 2015

Research article 23 Oct 2015

Research article | 23 Oct 2015

Spatial mapping of ground-based observations of total ozone

K.-L. Chang1, S. Guillas1, and V. E. Fioletov2 K.-L. Chang et al.
  • 1Department of Statistical Science, University College London, London, UK
  • 2Environment Canada, Toronto, Ontario, Canada

Abstract. Total column ozone variations estimated using ground-based stations provide important independent source of information in addition to satellite-based estimates. This estimation has been vigorously challenged by data inhomogeneity in time and by the irregularity of the spatial distribution of stations, as well as by interruptions in observation records. Furthermore, some stations have calibration issues and thus observations may drift. In this paper we compare the spatial interpolation of ozone levels using the novel stochastic partial differential equation (SPDE) approach with the covariance-based kriging. We show how these new spatial predictions are more accurate, less uncertain and more robust. We construct long-term zonal means to investigate the robustness against the absence of measurements at some stations as well as instruments drifts. We conclude that time series analyzes can benefit from the SPDE approach compared to the covariance-based kriging when stations are missing, but the positive impact of the technique is less pronounced in the case of drifts.

Short summary
The aim of this article is to analyze the total column ozone data from the World Ozone and Ultraviolet Radiation Data Centre (WOUDC) that consists of around 150 stations irregularly spaced over the globe. Our use of a new statistical spatial technique over the globe can greatly outperform the currently used spatial approximation of the total column ozone in terms of approximation. We feel that this technique could benefit the ozone science community.