Ensemble sensitivity analysis of Greenland blocking in medium‐range forecasts
The North Atlantic Oscillation (NAO) is the leading mode of variability in the large‐scale circulation over the North Atlantic in winter, and strongly influences the weather and climate of Europe. On synoptic time‐scales, the negative phase of the NAO often corresponds to the occurrence of a blockin...
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crwiley:10.1002/qj.3391 2024-06-23T07:53:13+00:00 Ensemble sensitivity analysis of Greenland blocking in medium‐range forecasts Parker, Tess Woollings, Tim Weisheimer, Antje Natural Environment Research Council 2018 http://dx.doi.org/10.1002/qj.3391 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fqj.3391 https://onlinelibrary.wiley.com/doi/pdf/10.1002/qj.3391 https://onlinelibrary.wiley.com/doi/full-xml/10.1002/qj.3391 https://rmets.onlinelibrary.wiley.com/doi/pdf/10.1002/qj.3391 en eng Wiley http://creativecommons.org/licenses/by/4.0/ Quarterly Journal of the Royal Meteorological Society volume 144, issue 716, page 2358-2379 ISSN 0035-9009 1477-870X journal-article 2018 crwiley https://doi.org/10.1002/qj.3391 2024-06-13T04:25:05Z The North Atlantic Oscillation (NAO) is the leading mode of variability in the large‐scale circulation over the North Atlantic in winter, and strongly influences the weather and climate of Europe. On synoptic time‐scales, the negative phase of the NAO often corresponds to the occurrence of a blocking episode over Greenland. Hence, the dynamics and predictability of these blocking events is of interest for the prediction of the NAO and its related impacts over a wide region. Ensemble sensitivity analysis utilises the information contained in probabilistic forecast ensembles to calculate a statistical relationship between a forecast metric and some precursor condition. Here the method is applied to 15‐day forecasts of a set of 26 Greenland blocking events using the state‐of‐the‐art European Centre for Medium‐Range Weather Forecasts (ECMWF) forecasting system. The ensemble sensitivity analysis shows that Greenland blocking does not develop in isolation in these forecasts, but instead the blocking is sensitive to remote precursors, such as 500 and 50 hPa geopotential height, particularly in the low‐frequency flow. In general, there are more significant sensitivities to anomalies in the Tropics than in the polar regions. Stratospheric sensitivities tend to emerge at later lead times than tropospheric sensitivities. The strongest and most robust sensitivities correspond to a Rossby wave precursor reaching from the Pacific basin across North America. Article in Journal/Newspaper Greenland North Atlantic North Atlantic oscillation Wiley Online Library Greenland Pacific Quarterly Journal of the Royal Meteorological Society 144 716 2358 2379 |
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Wiley Online Library |
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crwiley |
language |
English |
description |
The North Atlantic Oscillation (NAO) is the leading mode of variability in the large‐scale circulation over the North Atlantic in winter, and strongly influences the weather and climate of Europe. On synoptic time‐scales, the negative phase of the NAO often corresponds to the occurrence of a blocking episode over Greenland. Hence, the dynamics and predictability of these blocking events is of interest for the prediction of the NAO and its related impacts over a wide region. Ensemble sensitivity analysis utilises the information contained in probabilistic forecast ensembles to calculate a statistical relationship between a forecast metric and some precursor condition. Here the method is applied to 15‐day forecasts of a set of 26 Greenland blocking events using the state‐of‐the‐art European Centre for Medium‐Range Weather Forecasts (ECMWF) forecasting system. The ensemble sensitivity analysis shows that Greenland blocking does not develop in isolation in these forecasts, but instead the blocking is sensitive to remote precursors, such as 500 and 50 hPa geopotential height, particularly in the low‐frequency flow. In general, there are more significant sensitivities to anomalies in the Tropics than in the polar regions. Stratospheric sensitivities tend to emerge at later lead times than tropospheric sensitivities. The strongest and most robust sensitivities correspond to a Rossby wave precursor reaching from the Pacific basin across North America. |
author2 |
Natural Environment Research Council |
format |
Article in Journal/Newspaper |
author |
Parker, Tess Woollings, Tim Weisheimer, Antje |
spellingShingle |
Parker, Tess Woollings, Tim Weisheimer, Antje Ensemble sensitivity analysis of Greenland blocking in medium‐range forecasts |
author_facet |
Parker, Tess Woollings, Tim Weisheimer, Antje |
author_sort |
Parker, Tess |
title |
Ensemble sensitivity analysis of Greenland blocking in medium‐range forecasts |
title_short |
Ensemble sensitivity analysis of Greenland blocking in medium‐range forecasts |
title_full |
Ensemble sensitivity analysis of Greenland blocking in medium‐range forecasts |
title_fullStr |
Ensemble sensitivity analysis of Greenland blocking in medium‐range forecasts |
title_full_unstemmed |
Ensemble sensitivity analysis of Greenland blocking in medium‐range forecasts |
title_sort |
ensemble sensitivity analysis of greenland blocking in medium‐range forecasts |
publisher |
Wiley |
publishDate |
2018 |
url |
http://dx.doi.org/10.1002/qj.3391 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fqj.3391 https://onlinelibrary.wiley.com/doi/pdf/10.1002/qj.3391 https://onlinelibrary.wiley.com/doi/full-xml/10.1002/qj.3391 https://rmets.onlinelibrary.wiley.com/doi/pdf/10.1002/qj.3391 |
geographic |
Greenland Pacific |
geographic_facet |
Greenland Pacific |
genre |
Greenland North Atlantic North Atlantic oscillation |
genre_facet |
Greenland North Atlantic North Atlantic oscillation |
op_source |
Quarterly Journal of the Royal Meteorological Society volume 144, issue 716, page 2358-2379 ISSN 0035-9009 1477-870X |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1002/qj.3391 |
container_title |
Quarterly Journal of the Royal Meteorological Society |
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144 |
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716 |
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2358 |
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2379 |
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1802644778690543616 |