Lengthening of summer season over the Northern Hemisphere under 1.5 °C and 2.0 °C global warming
Summer season has lengthened substantially across Northern Hemisphere (NH) land over the past decades, which has been attributed to anthropogenic greenhouse gas increases. This study examines additional future changes in summer season onset and withdrawal under 1.5 °C and 2.0 °C global warming condi...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2021-01-01
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| Series: | Environmental Research Letters |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1748-9326/ac3f64 |
| _version_ | 1797747143279116288 |
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| author | Bo-Joung Park Seung-Ki Min Evan Weller |
| author_facet | Bo-Joung Park Seung-Ki Min Evan Weller |
| author_sort | Bo-Joung Park |
| collection | DOAJ |
| description | Summer season has lengthened substantially across Northern Hemisphere (NH) land over the past decades, which has been attributed to anthropogenic greenhouse gas increases. This study examines additional future changes in summer season onset and withdrawal under 1.5 °C and 2.0 °C global warming conditions using multiple atmospheric global climate model (AGCM) large-ensemble simulations from the Half a degree Additional warming, Prognosis and Projected Impacts project. Five AGCMs provide more than 100 runs of 10 year length for three experiments: All-Hist (current decade: 2006–2015), Plus15, and Plus20 (1.5 °C and 2.0 °C above pre-industrial condition, respectively). Results show that with 1.5 °C and 2.0 °C warmer conditions summer season will become longer by a few days to weeks over entire NH extratropical lands, with slightly larger contributions by delay in withdrawal due to stronger warming in late summer. Stronger changes are observed more in lower latitudes than higher latitudes and largest expansion (up to three weeks) is found over East Asia and the Mediterranean. Associated changes in summer-like day frequency is further analyzed focusing on the extended summer edges. The hot days occur more frequently in lower latitudes including East Asia, USA and Mediterranean, in accord with largest summer season lengthening. Further, difference between Plus15 and Plus20 experiments indicates that summer season lengthening and associated increases in hot days can be reduced significantly if warming is limited to 1.5 °C. Overall, similar results are obtained from Coupled Model Intercomparison Project phase 5 coupled GCM simulations (based on RCP8.5 scenario experiments), suggesting a weak influence of air-sea coupling on summer season timing changes. |
| first_indexed | 2024-03-12T15:46:57Z |
| format | Article |
| id | doaj.art-5ef9d8e57fca4e1a8a074d90d5189300 |
| institution | Directory Open Access Journal |
| issn | 1748-9326 |
| language | English |
| last_indexed | 2024-03-12T15:46:57Z |
| publishDate | 2021-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | Environmental Research Letters |
| spelling | doaj.art-5ef9d8e57fca4e1a8a074d90d51893002023-08-09T15:22:58ZengIOP PublishingEnvironmental Research Letters1748-93262021-01-0117101401210.1088/1748-9326/ac3f64Lengthening of summer season over the Northern Hemisphere under 1.5 °C and 2.0 °C global warmingBo-Joung Park0Seung-Ki Min1https://orcid.org/0000-0002-6749-010XEvan Weller2https://orcid.org/0000-0002-7454-9827Division of Environmental Science and Engineering, Pohang University of Science and Technology , Pohang, Republic of KoreaDivision of Environmental Science and Engineering, Pohang University of Science and Technology , Pohang, Republic of Korea; Institute for Convergence Research and Education in Advanced Technology, Yonsei University , Incheon, Republic of KoreaSchool of Environment, University of Auckland , Auckland, New ZealandSummer season has lengthened substantially across Northern Hemisphere (NH) land over the past decades, which has been attributed to anthropogenic greenhouse gas increases. This study examines additional future changes in summer season onset and withdrawal under 1.5 °C and 2.0 °C global warming conditions using multiple atmospheric global climate model (AGCM) large-ensemble simulations from the Half a degree Additional warming, Prognosis and Projected Impacts project. Five AGCMs provide more than 100 runs of 10 year length for three experiments: All-Hist (current decade: 2006–2015), Plus15, and Plus20 (1.5 °C and 2.0 °C above pre-industrial condition, respectively). Results show that with 1.5 °C and 2.0 °C warmer conditions summer season will become longer by a few days to weeks over entire NH extratropical lands, with slightly larger contributions by delay in withdrawal due to stronger warming in late summer. Stronger changes are observed more in lower latitudes than higher latitudes and largest expansion (up to three weeks) is found over East Asia and the Mediterranean. Associated changes in summer-like day frequency is further analyzed focusing on the extended summer edges. The hot days occur more frequently in lower latitudes including East Asia, USA and Mediterranean, in accord with largest summer season lengthening. Further, difference between Plus15 and Plus20 experiments indicates that summer season lengthening and associated increases in hot days can be reduced significantly if warming is limited to 1.5 °C. Overall, similar results are obtained from Coupled Model Intercomparison Project phase 5 coupled GCM simulations (based on RCP8.5 scenario experiments), suggesting a weak influence of air-sea coupling on summer season timing changes.https://doi.org/10.1088/1748-9326/ac3f64summer season lengthglobal warmingParis Agreementseasonal cycle |
| spellingShingle | Bo-Joung Park Seung-Ki Min Evan Weller Lengthening of summer season over the Northern Hemisphere under 1.5 °C and 2.0 °C global warming Environmental Research Letters summer season length global warming Paris Agreement seasonal cycle |
| title | Lengthening of summer season over the Northern Hemisphere under 1.5 °C and 2.0 °C global warming |
| title_full | Lengthening of summer season over the Northern Hemisphere under 1.5 °C and 2.0 °C global warming |
| title_fullStr | Lengthening of summer season over the Northern Hemisphere under 1.5 °C and 2.0 °C global warming |
| title_full_unstemmed | Lengthening of summer season over the Northern Hemisphere under 1.5 °C and 2.0 °C global warming |
| title_short | Lengthening of summer season over the Northern Hemisphere under 1.5 °C and 2.0 °C global warming |
| title_sort | lengthening of summer season over the northern hemisphere under 1 5 °c and 2 0 °c global warming |
| topic | summer season length global warming Paris Agreement seasonal cycle |
| url | https://doi.org/10.1088/1748-9326/ac3f64 |
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