On the effect of reference periods on trends in percentile-based extreme temperature indices
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...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2022-01-01
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| Series: | Environmental Research Letters |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1748-9326/ac52c8 |
| _version_ | 1797747097093537792 |
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| author | Robert J H Dunn Colin P Morice |
| author_facet | Robert J H Dunn Colin P Morice |
| author_sort | Robert J H Dunn |
| collection | DOAJ |
| description | 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. |
| first_indexed | 2024-03-12T15:47:17Z |
| format | Article |
| id | doaj.art-b5a7405d82f4432397b5a8d6412b229c |
| institution | Directory Open Access Journal |
| issn | 1748-9326 |
| language | English |
| last_indexed | 2024-03-12T15:47:17Z |
| publishDate | 2022-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | Environmental Research Letters |
| spelling | doaj.art-b5a7405d82f4432397b5a8d6412b229c2023-08-09T15:24:41ZengIOP PublishingEnvironmental Research Letters1748-93262022-01-0117303402610.1088/1748-9326/ac52c8On the effect of reference periods on trends in percentile-based extreme temperature indicesRobert J H Dunn0https://orcid.org/0000-0003-2469-5989Colin P Morice1https://orcid.org/0000-0002-5656-1021Met Office Hadley Centre , Fitz Roy Road, Exeter, EX1 3PB, United KingdomMet Office Hadley Centre , Fitz Roy Road, Exeter, EX1 3PB, United KingdomA 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.https://doi.org/10.1088/1748-9326/ac52c8reference periodclimate extremes indicespercentile-based indiceswarming trends |
| spellingShingle | Robert J H Dunn Colin P Morice On the effect of reference periods on trends in percentile-based extreme temperature indices Environmental Research Letters reference period climate extremes indices percentile-based indices warming trends |
| title | On the effect of reference periods on trends in percentile-based extreme temperature indices |
| title_full | On the effect of reference periods on trends in percentile-based extreme temperature indices |
| title_fullStr | On the effect of reference periods on trends in percentile-based extreme temperature indices |
| title_full_unstemmed | On the effect of reference periods on trends in percentile-based extreme temperature indices |
| title_short | On the effect of reference periods on trends in percentile-based extreme temperature indices |
| title_sort | on the effect of reference periods on trends in percentile based extreme temperature indices |
| topic | reference period climate extremes indices percentile-based indices warming trends |
| url | https://doi.org/10.1088/1748-9326/ac52c8 |
| work_keys_str_mv | AT robertjhdunn ontheeffectofreferenceperiodsontrendsinpercentilebasedextremetemperatureindices AT colinpmorice ontheeffectofreferenceperiodsontrendsinpercentilebasedextremetemperatureindices |