%0 Journal Article %1 Dunn2022Effect %A Dunn, Robert J H %A Morice, Colin P %D 2022 %I IOP Publishing %J Environmental Research Letters %K climate probabilistic time-series %N 3 %P 034026 %R 10.1088/1748-9326/ac52c8 %T On the effect of reference periods on trends in percentile-based extreme temperature indices %U https://doi.org/10.1088%2F1748-9326%2Fac52c8 %V 17 %X ERL graphic iopscience_header.jpg LETTER • THE FOLLOWING ARTICLE ISOPEN ACCESS On the effect of reference periods on trends in percentile-based extreme temperature indices Robert J H Dunn2,1 and Colin P Morice1 Published 25 February 2022 • © 2022 The Author(s). Published by IOP Publishing Ltd Environmental Research Letters, Volume 17, Number 3 Citation Robert J H Dunn and Colin P Morice 2022 Environ. Res. Lett. 17 034026 DownloadArticle PDF DownloadArticle ePub Figures References Download PDFDownload ePub 123 Total downloads Turn on MathJax Share this article Share this content via email Share on Facebook (opens new window) Share on Twitter (opens new window) Share on Mendeley (opens new window) Hide article information Author e-mails robert.dunn@metoffice.gov.uk Author affiliations 1 Met Office Hadley Centre, Fitz Roy Road, Exeter, EX1 3PB, United Kingdom Author notes 2 Author to whom any correspondence should be addressed. ORCID iDs Robert J H Dunn https://orcid.org/0000-0003-2469-5989 Colin P Morice https://orcid.org/0000-0002-5656-1021 Dates Received 29 October 2021 Accepted 8 February 2022 Published 25 February 2022 Check for updates using Crossmark Peer review information Method: Single-anonymous Revisions: 1 Screened for originality? Yes DOI https://doi.org/10.1088/1748-9326/ac52c8 Buy this article in print Journal RSS Sign up for new issue notifications Create citation alert Abstract A number of studies have noted that the use of distinct reference periods when comparing indices measuring the frequency of days exceeding a particular temperature percentile threshold leads to apparently different behaviour. We show that these differences arise because of the interplay between the increasing temperatures and the choice of reference period. The time series of the indicators calculated using the different reference periods are offset, as expected, but also diverge. Linear trends calculated over the same period from the same underlying data but where different reference periods have been used are substantially different if a change in climatological conditions has occurred between the two reference periods. We show this not only occurs in our simple empirical approach, but also for the averages of gridded observational and reanalysis datasets and also at a station level. This has implications for data set comparisons using trends in temperature percentile indices that are based on different reference periods. It also has implications for updates to standard reference periods used to monitor the climate.

@article{Dunn2022Effect, abstract = {ERL graphic iopscience_header.jpg LETTER • THE FOLLOWING ARTICLE ISOPEN ACCESS On the effect of reference periods on trends in percentile-based extreme temperature indices Robert J H Dunn2,1 and Colin P Morice1 Published 25 February 2022 • © 2022 The Author(s). Published by IOP Publishing Ltd Environmental Research Letters, Volume 17, Number 3 Citation Robert J H Dunn and Colin P Morice 2022 Environ. Res. Lett. 17 034026 DownloadArticle PDF DownloadArticle ePub Figures References Download PDFDownload ePub 123 Total downloads Turn on MathJax Share this article Share this content via email Share on Facebook (opens new window) Share on Twitter (opens new window) Share on Mendeley (opens new window) Hide article information Author e-mails robert.dunn@metoffice.gov.uk Author affiliations 1 Met Office Hadley Centre, Fitz Roy Road, Exeter, EX1 3PB, United Kingdom Author notes 2 Author to whom any correspondence should be addressed. ORCID iDs Robert J H Dunn https://orcid.org/0000-0003-2469-5989 Colin P Morice https://orcid.org/0000-0002-5656-1021 Dates Received 29 October 2021 Accepted 8 February 2022 Published 25 February 2022 Check for updates using Crossmark Peer review information Method: Single-anonymous Revisions: 1 Screened for originality? Yes DOI https://doi.org/10.1088/1748-9326/ac52c8 Buy this article in print Journal RSS Sign up for new issue notifications Create citation alert Abstract A number of studies have noted that the use of distinct reference periods when comparing indices measuring the frequency of days exceeding a particular temperature percentile threshold leads to apparently different behaviour. We show that these differences arise because of the interplay between the increasing temperatures and the choice of reference period. The time series of the indicators calculated using the different reference periods are offset, as expected, but also diverge. Linear trends calculated over the same period from the same underlying data but where different reference periods have been used are substantially different if a change in climatological conditions has occurred between the two reference periods. We show this not only occurs in our simple empirical approach, but also for the averages of gridded observational and reanalysis datasets and also at a station level. This has implications for data set comparisons using trends in temperature percentile indices that are based on different reference periods. It also has implications for updates to standard reference periods used to monitor the climate.}, added-at = {2022-03-11T17:21:08.000+0100}, author = {Dunn, Robert J H and Morice, Colin P}, biburl = {https://www.bibsonomy.org/bibtex/288822a0f527f8de984e7e12a1e71f417/verifier}, doi = {10.1088/1748-9326/ac52c8}, interhash = {fbe79d02b605d5808e44df22ee4a9686}, intrahash = {88822a0f527f8de984e7e12a1e71f417}, journal = {Environmental Research Letters}, keywords = {climate probabilistic time-series}, month = feb, number = 3, pages = 034026, publisher = {{IOP} Publishing}, timestamp = {2022-03-11T17:21:08.000+0100}, title = {On the effect of reference periods on trends in percentile-based extreme temperature indices}, url = {https://doi.org/10.1088%2F1748-9326%2Fac52c8}, volume = 17, year = 2022 }