Bidimensional climatology and trends of Northern Hemisphere blocking utilizing a new detection method
Abstract In this article, the meridional gradient of daily potential vorticity (PV) on the 330 K isentropic surface is used to identify atmospheric blocking events for the period 1979–2019. The associated two‐dimensional index considers not only Rossby wave breaking, but also energy dispersion and n...
Published in: | Quarterly Journal of the Royal Meteorological Society |
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Online Access: | http://dx.doi.org/10.1002/qj.4489 https://rmets.onlinelibrary.wiley.com/doi/pdf/10.1002/qj.4489 |
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crwiley:10.1002/qj.4489 2024-10-13T14:07:43+00:00 Bidimensional climatology and trends of Northern Hemisphere blocking utilizing a new detection method Li, Muyuan Luo, Dehai Simmonds, Ian Yao, Yao Zhong, Linhao National Natural Science Foundation of China 2023 http://dx.doi.org/10.1002/qj.4489 https://rmets.onlinelibrary.wiley.com/doi/pdf/10.1002/qj.4489 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Quarterly Journal of the Royal Meteorological Society volume 149, issue 754, page 1932-1952 ISSN 0035-9009 1477-870X journal-article 2023 crwiley https://doi.org/10.1002/qj.4489 2024-09-19T04:19:32Z Abstract In this article, the meridional gradient of daily potential vorticity (PV) on the 330 K isentropic surface is used to identify atmospheric blocking events for the period 1979–2019. The associated two‐dimensional index considers not only Rossby wave breaking, but also energy dispersion and nonlinearity of blocking systems, and thus has a solid theoretical foundation. It also has the advantage of automatically excluding subtropical high‐pressure systems in summer and autumn. The index reveals that the Northern Hemisphere exhibits high blocking frequency over Euro‐Atlantic, North Pacific and Greenland in winter, spring and autumn, and over two wide‐extended bands at high latitudes in summer. Two prominent blocking episode (BE) intensity centres are found over the eastern Atlantic and eastern Pacific in all seasons, while the long‐lived BE is primarily situated in regions with high BE frequency. There is more frequent and longer‐lived BE in the Euro‐Atlantic sector than in the North Pacific, whereas the BE in the North Pacific is more intense. Notably, with the same poleward criterion for the four seasons, the BE frequency and duration are supposed to be overestimated in summer. Comparing our blocking detection method with previous blocking indices provides additional information about the long‐term trends for blocking frequency and intensity, which can be useful to our understanding of future extremes on climate time‐scales. It is found that both blocking frequency and intensity exhibit upward linear trends in the Ural region and Barents–Kara Sea in winter, Europe, northern North Pacific and East Siberia in spring, western Greenland in summer, as well as Norwegian Sea, Europe and North Atlantic in autumn, which point to increases in high‐impact weather events in these regions. Article in Journal/Newspaper Greenland Kara Sea North Atlantic Norwegian Sea Siberia Wiley Online Library Norwegian Sea Kara Sea Greenland Pacific Quarterly Journal of the Royal Meteorological Society 149 754 1932 1952 |
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Open Polar |
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Wiley Online Library |
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crwiley |
language |
English |
description |
Abstract In this article, the meridional gradient of daily potential vorticity (PV) on the 330 K isentropic surface is used to identify atmospheric blocking events for the period 1979–2019. The associated two‐dimensional index considers not only Rossby wave breaking, but also energy dispersion and nonlinearity of blocking systems, and thus has a solid theoretical foundation. It also has the advantage of automatically excluding subtropical high‐pressure systems in summer and autumn. The index reveals that the Northern Hemisphere exhibits high blocking frequency over Euro‐Atlantic, North Pacific and Greenland in winter, spring and autumn, and over two wide‐extended bands at high latitudes in summer. Two prominent blocking episode (BE) intensity centres are found over the eastern Atlantic and eastern Pacific in all seasons, while the long‐lived BE is primarily situated in regions with high BE frequency. There is more frequent and longer‐lived BE in the Euro‐Atlantic sector than in the North Pacific, whereas the BE in the North Pacific is more intense. Notably, with the same poleward criterion for the four seasons, the BE frequency and duration are supposed to be overestimated in summer. Comparing our blocking detection method with previous blocking indices provides additional information about the long‐term trends for blocking frequency and intensity, which can be useful to our understanding of future extremes on climate time‐scales. It is found that both blocking frequency and intensity exhibit upward linear trends in the Ural region and Barents–Kara Sea in winter, Europe, northern North Pacific and East Siberia in spring, western Greenland in summer, as well as Norwegian Sea, Europe and North Atlantic in autumn, which point to increases in high‐impact weather events in these regions. |
author2 |
National Natural Science Foundation of China |
format |
Article in Journal/Newspaper |
author |
Li, Muyuan Luo, Dehai Simmonds, Ian Yao, Yao Zhong, Linhao |
spellingShingle |
Li, Muyuan Luo, Dehai Simmonds, Ian Yao, Yao Zhong, Linhao Bidimensional climatology and trends of Northern Hemisphere blocking utilizing a new detection method |
author_facet |
Li, Muyuan Luo, Dehai Simmonds, Ian Yao, Yao Zhong, Linhao |
author_sort |
Li, Muyuan |
title |
Bidimensional climatology and trends of Northern Hemisphere blocking utilizing a new detection method |
title_short |
Bidimensional climatology and trends of Northern Hemisphere blocking utilizing a new detection method |
title_full |
Bidimensional climatology and trends of Northern Hemisphere blocking utilizing a new detection method |
title_fullStr |
Bidimensional climatology and trends of Northern Hemisphere blocking utilizing a new detection method |
title_full_unstemmed |
Bidimensional climatology and trends of Northern Hemisphere blocking utilizing a new detection method |
title_sort |
bidimensional climatology and trends of northern hemisphere blocking utilizing a new detection method |
publisher |
Wiley |
publishDate |
2023 |
url |
http://dx.doi.org/10.1002/qj.4489 https://rmets.onlinelibrary.wiley.com/doi/pdf/10.1002/qj.4489 |
geographic |
Norwegian Sea Kara Sea Greenland Pacific |
geographic_facet |
Norwegian Sea Kara Sea Greenland Pacific |
genre |
Greenland Kara Sea North Atlantic Norwegian Sea Siberia |
genre_facet |
Greenland Kara Sea North Atlantic Norwegian Sea Siberia |
op_source |
Quarterly Journal of the Royal Meteorological Society volume 149, issue 754, page 1932-1952 ISSN 0035-9009 1477-870X |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1002/qj.4489 |
container_title |
Quarterly Journal of the Royal Meteorological Society |
container_volume |
149 |
container_issue |
754 |
container_start_page |
1932 |
op_container_end_page |
1952 |
_version_ |
1812814235440250880 |