\documentclass[11pt]{article} \setlength{\oddsidemargin}{0.0truein} \setlength{\evensidemargin}{0.0truein} \setlength{\textwidth}{6.5truein} \setlength{\topmargin}{0.0truein} \setlength{\textheight}{9.0truein} \setlength{\headsep}{0.0truein} \setlength{\headheight}{0.0truein} \setlength{\topskip}{10.0pt} \setlength{\parskip}{5mm} \usepackage{url} \begin{document} \begin{center} \textbf{\textsc{STANFORD UNIVERSITY}}\\[5pt] \textbf{\textsc{DEPARTMENT OF STATISTICS}}\\[5pt] \Large{\textbf\textsc{{DEPARTMENTAL SEMINAR}}} \end{center} \begin{center} 4:15 p.m., Tuesday, May 2, 2006\\ Sequoia Hall Room 200\\ (Cookies at 3:45 in 1st Floor Lounge) \end{center} \begin{center} \textsl{Michael Stein }\\ University of Chicago \end{center} \begin{center} \textbf{ Seasonal variations in the spatial-temporal dependence \\ of total column ozone } \end{center} \noindent The Total Ozone Mapping Spectrometer (TOMS) is a satellite-based instrument that measures total column ozone on a daily basis over a fairly dense spatial grid with near global coverage. Statistical models for the spatial-temporal variations in total column ozone provide insights into ozone dynamics, are valuable for obtaining inferences on long-term trends in ozone levels, and can be used to predict ozone levels at unobserved points in space-time. However, developing such a model is complicated by the seasonally varying nature of the space-time dependence and the partial confounding of spatial and temporal variation caused by the sun-synchronous orbit of the satellite. I will consider methods for describing, modeling and estimating the seasonal patterns in the dependence structure for measurements at a single latitude. Applying one of these models to the synoptic prediction of total column ozone at a latitude shows that there is at least the potential for substantially improved predictions by exploiting the high spatial density of observations TOMS provides. I will also take a brief look at a less processed version of the TOMS data in an effort to disentangle smaller scale spatial and temporal variation. \end{document}