Signal and noise in regime systems: A hypothesis on the predictability of the North Atlantic Oscillation
Studies conducted by the UK Met Office reported significant skill in predicting the winter North Atlantic Oscillation (NAO) index with their seasonal prediction system. At the same time, a very low signal‐to‐noise ratio was observed, as measured using the “ratio of predictable components” (RPC) metr...
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Online Access: | https://doi.org/10.1002/qj.3414 https://ora.ox.ac.uk/objects/uuid:0033d709-5147-4d95-a330-7420d39887ec |
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ftuloxford:oai:ora.ox.ac.uk:uuid:0033d709-5147-4d95-a330-7420d39887ec 2023-05-15T17:29:29+02:00 Signal and noise in regime systems: A hypothesis on the predictability of the North Atlantic Oscillation Strommen, K Palmer, T 2019-01-15 https://doi.org/10.1002/qj.3414 https://ora.ox.ac.uk/objects/uuid:0033d709-5147-4d95-a330-7420d39887ec unknown Royal Meteorological Society doi:10.1002/qj.3414 https://ora.ox.ac.uk/objects/uuid:0033d709-5147-4d95-a330-7420d39887ec https://doi.org/10.1002/qj.3414 info:eu-repo/semantics/openAccess Journal article 2019 ftuloxford https://doi.org/10.1002/qj.3414 2022-06-28T20:04:34Z Studies conducted by the UK Met Office reported significant skill in predicting the winter North Atlantic Oscillation (NAO) index with their seasonal prediction system. At the same time, a very low signal‐to‐noise ratio was observed, as measured using the “ratio of predictable components” (RPC) metric. We analyse both the skill and signal‐to‐noise ratio using a new statistical toy model, which assumes NAO predictability is driven by regime dynamics. It is shown that if the system is approximately bimodal in nature, with the model consistently underestimating the level of regime persistence each season, then both the high skill and high RPC value of the Met Office hindcasts can easily be reproduced. Underestimation of regime persistence could be attributable to any number of sources of model error, including imperfect regime structure or errors in the propagation of teleconnections. In particular, a high RPC value for a seasonal mean prediction may be expected even if the model's internal level of noise is realistic. Article in Journal/Newspaper North Atlantic North Atlantic oscillation ORA - Oxford University Research Archive Quarterly Journal of the Royal Meteorological Society 145 718 147 163 |
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Open Polar |
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ORA - Oxford University Research Archive |
op_collection_id |
ftuloxford |
language |
unknown |
description |
Studies conducted by the UK Met Office reported significant skill in predicting the winter North Atlantic Oscillation (NAO) index with their seasonal prediction system. At the same time, a very low signal‐to‐noise ratio was observed, as measured using the “ratio of predictable components” (RPC) metric. We analyse both the skill and signal‐to‐noise ratio using a new statistical toy model, which assumes NAO predictability is driven by regime dynamics. It is shown that if the system is approximately bimodal in nature, with the model consistently underestimating the level of regime persistence each season, then both the high skill and high RPC value of the Met Office hindcasts can easily be reproduced. Underestimation of regime persistence could be attributable to any number of sources of model error, including imperfect regime structure or errors in the propagation of teleconnections. In particular, a high RPC value for a seasonal mean prediction may be expected even if the model's internal level of noise is realistic. |
format |
Article in Journal/Newspaper |
author |
Strommen, K Palmer, T |
spellingShingle |
Strommen, K Palmer, T Signal and noise in regime systems: A hypothesis on the predictability of the North Atlantic Oscillation |
author_facet |
Strommen, K Palmer, T |
author_sort |
Strommen, K |
title |
Signal and noise in regime systems: A hypothesis on the predictability of the North Atlantic Oscillation |
title_short |
Signal and noise in regime systems: A hypothesis on the predictability of the North Atlantic Oscillation |
title_full |
Signal and noise in regime systems: A hypothesis on the predictability of the North Atlantic Oscillation |
title_fullStr |
Signal and noise in regime systems: A hypothesis on the predictability of the North Atlantic Oscillation |
title_full_unstemmed |
Signal and noise in regime systems: A hypothesis on the predictability of the North Atlantic Oscillation |
title_sort |
signal and noise in regime systems: a hypothesis on the predictability of the north atlantic oscillation |
publisher |
Royal Meteorological Society |
publishDate |
2019 |
url |
https://doi.org/10.1002/qj.3414 https://ora.ox.ac.uk/objects/uuid:0033d709-5147-4d95-a330-7420d39887ec |
genre |
North Atlantic North Atlantic oscillation |
genre_facet |
North Atlantic North Atlantic oscillation |
op_relation |
doi:10.1002/qj.3414 https://ora.ox.ac.uk/objects/uuid:0033d709-5147-4d95-a330-7420d39887ec https://doi.org/10.1002/qj.3414 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1002/qj.3414 |
container_title |
Quarterly Journal of the Royal Meteorological Society |
container_volume |
145 |
container_issue |
718 |
container_start_page |
147 |
op_container_end_page |
163 |
_version_ |
1766123617862549504 |