Heat waves in Finland : present and projected summertime extreme temperatures and their associated circulation patterns
The number and intensity of individual hot days affecting Finland in the current and future climate is investigated together with the circulation patterns associated with the hot days. In addition, the number, length and intensity of heat waves lasting at least 3 days is also considered. ERA-Interim...
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ftunivhelsihelda:oai:helda.helsinki.fi:10138/327668 2024-01-07T09:45:29+01:00 Heat waves in Finland : present and projected summertime extreme temperatures and their associated circulation patterns Kim, Sol Sinclair, Victoria A. Räisänen, Jouni Ruuhela, Reija Department of Physics 2021-03-09T06:45:01Z 16 application/pdf http://hdl.handle.net/10138/327668 eng eng Wiley 10.1002/joc.5253 Kim , S , Sinclair , V A , Räisänen , J & Ruuhela , R 2018 , ' Heat waves in Finland : present and projected summertime extreme temperatures and their associated circulation patterns ' , International Journal of Climatology , vol. 38 , no. 3 , pp. 1393–1408 . https://doi.org/10.1002/joc.5253 ORCID: /0000-0003-3657-1588/work/42361474 ORCID: /0000-0002-2125-4726/work/42361509 85028344230 33c1cd83-1573-4912-8fc0-7b5aacc61e41 http://hdl.handle.net/10138/327668 000426729300021 openAccess info:eu-repo/semantics/openAccess 114 Physical sciences CLIMATE CHANGE Meteorologia circulation patterns CMIP5 Finland heat waves EUROPE Article acceptedVersion 2021 ftunivhelsihelda 2023-12-14T00:15:12Z The number and intensity of individual hot days affecting Finland in the current and future climate is investigated together with the circulation patterns associated with the hot days. In addition, the number, length and intensity of heat waves lasting at least 3 days is also considered. ERA-Interim reanalysis data and both direct model output and bias-corrected data for historical and future climate [representative concentration pathway 4.5 (RCP4.5) scenario] simulations from 17 global climate models are analysed. Three intensities of heat waves and hot days are defined based on daily mean temperature thresholds of 20, 24 and 28 °C. The percentage of summertime days which exceed these temperature thresholds is shown to increase in the future. In ERA-Interim, 24% of summertime days in southern Finland exceed the lowest temperature threshold while none exceed the highest temperature threshold. Under the RCP4.5 scenario these values increase to 47 and 1%, respectively. Larger relative changes occur in northern Finland. Heat waves are also longer in the RCP4.5 simulations than in the historical simulations. In southern Finland, the mean length of a heat wave where the 20 °C daily mean temperature is exceeded is 6.1 days in the historical simulations but increases to 9.4 days in the RCP4.5 simulations. The hot days in both northern and southern Finland are associated with a statistically significant positive pressure anomaly over Finland and to the east to Finland and a statistically significant negative pressure anomaly over Russia between 90 and 120°E. These pressure anomalies were evident for all intensities of hot days in the current climate and the future climate. The magnitude of the pressure anomalies increases as the daily mean temperature threshold increases. However, for hot days which exceed the same daily mean temperature threshold, the pressure anomalies are weaker in the RCP4.5 simulations than in the historical or ERA-Interim data. Peer reviewed Article in Journal/Newspaper Northern Finland HELDA – University of Helsinki Open Repository International Journal of Climatology 38 3 1393 1408 |
institution |
Open Polar |
collection |
HELDA – University of Helsinki Open Repository |
op_collection_id |
ftunivhelsihelda |
language |
English |
topic |
114 Physical sciences CLIMATE CHANGE Meteorologia circulation patterns CMIP5 Finland heat waves EUROPE |
spellingShingle |
114 Physical sciences CLIMATE CHANGE Meteorologia circulation patterns CMIP5 Finland heat waves EUROPE Kim, Sol Sinclair, Victoria A. Räisänen, Jouni Ruuhela, Reija Heat waves in Finland : present and projected summertime extreme temperatures and their associated circulation patterns |
topic_facet |
114 Physical sciences CLIMATE CHANGE Meteorologia circulation patterns CMIP5 Finland heat waves EUROPE |
description |
The number and intensity of individual hot days affecting Finland in the current and future climate is investigated together with the circulation patterns associated with the hot days. In addition, the number, length and intensity of heat waves lasting at least 3 days is also considered. ERA-Interim reanalysis data and both direct model output and bias-corrected data for historical and future climate [representative concentration pathway 4.5 (RCP4.5) scenario] simulations from 17 global climate models are analysed. Three intensities of heat waves and hot days are defined based on daily mean temperature thresholds of 20, 24 and 28 °C. The percentage of summertime days which exceed these temperature thresholds is shown to increase in the future. In ERA-Interim, 24% of summertime days in southern Finland exceed the lowest temperature threshold while none exceed the highest temperature threshold. Under the RCP4.5 scenario these values increase to 47 and 1%, respectively. Larger relative changes occur in northern Finland. Heat waves are also longer in the RCP4.5 simulations than in the historical simulations. In southern Finland, the mean length of a heat wave where the 20 °C daily mean temperature is exceeded is 6.1 days in the historical simulations but increases to 9.4 days in the RCP4.5 simulations. The hot days in both northern and southern Finland are associated with a statistically significant positive pressure anomaly over Finland and to the east to Finland and a statistically significant negative pressure anomaly over Russia between 90 and 120°E. These pressure anomalies were evident for all intensities of hot days in the current climate and the future climate. The magnitude of the pressure anomalies increases as the daily mean temperature threshold increases. However, for hot days which exceed the same daily mean temperature threshold, the pressure anomalies are weaker in the RCP4.5 simulations than in the historical or ERA-Interim data. Peer reviewed |
author2 |
Department of Physics |
format |
Article in Journal/Newspaper |
author |
Kim, Sol Sinclair, Victoria A. Räisänen, Jouni Ruuhela, Reija |
author_facet |
Kim, Sol Sinclair, Victoria A. Räisänen, Jouni Ruuhela, Reija |
author_sort |
Kim, Sol |
title |
Heat waves in Finland : present and projected summertime extreme temperatures and their associated circulation patterns |
title_short |
Heat waves in Finland : present and projected summertime extreme temperatures and their associated circulation patterns |
title_full |
Heat waves in Finland : present and projected summertime extreme temperatures and their associated circulation patterns |
title_fullStr |
Heat waves in Finland : present and projected summertime extreme temperatures and their associated circulation patterns |
title_full_unstemmed |
Heat waves in Finland : present and projected summertime extreme temperatures and their associated circulation patterns |
title_sort |
heat waves in finland : present and projected summertime extreme temperatures and their associated circulation patterns |
publisher |
Wiley |
publishDate |
2021 |
url |
http://hdl.handle.net/10138/327668 |
genre |
Northern Finland |
genre_facet |
Northern Finland |
op_relation |
10.1002/joc.5253 Kim , S , Sinclair , V A , Räisänen , J & Ruuhela , R 2018 , ' Heat waves in Finland : present and projected summertime extreme temperatures and their associated circulation patterns ' , International Journal of Climatology , vol. 38 , no. 3 , pp. 1393–1408 . https://doi.org/10.1002/joc.5253 ORCID: /0000-0003-3657-1588/work/42361474 ORCID: /0000-0002-2125-4726/work/42361509 85028344230 33c1cd83-1573-4912-8fc0-7b5aacc61e41 http://hdl.handle.net/10138/327668 000426729300021 |
op_rights |
openAccess info:eu-repo/semantics/openAccess |
container_title |
International Journal of Climatology |
container_volume |
38 |
container_issue |
3 |
container_start_page |
1393 |
op_container_end_page |
1408 |
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1787427027115048960 |