Good Practices and Common Pitfalls in Climate Time Series Changepoint Techniques: A Review

Authors

ROBERT B. LUND, University of California, Santa Cruz
CLAUDIE BEAULIEU, University of California, Santa Cruz
REBECCA KILLICK, Lancaster University
QIQI LU, University of California, Davis
XUEHENG SHI, University of Nebraska–LincolnFollow

Date of this Version

12-1-2023

Citation

VOLUME 36. JOURNAL OF CLIMATE. 1 DECEMBER 2023. DOI: 10.1175/JCLI-D-22-0954.1

Comments

Open access.

Abstract

Climate changepoint (homogenization) methods abound today, with a myriad of techniques existing in both the climate and statistics literature. Unfortunately, the appropriate changepoint technique to use remains unclear to many. Further complicating issues, changepoint conclusions are not robust to perturbations in assumptions; for example, allowing for a trend or correlation in the series can drastically change changepoint conclusions. This paper is a review of the topic, with an emphasis on illuminating the models and techniques that allow the scientist to make reliable conclusions. Pitfalls to avoid are demonstrated via actual applications. The discourse begins by narrating the salient statistical features of most climate time series. Thereafter, single- and multiple-changepoint problems are considered. Several pitfalls are discussed en route and good practices are recommended.While most of our applications involve temperatures, a sea ice series is also considered.