Impact of hindcast length on estimates of seasonal climate predictability
It has recently been argued that single-model seasonal forecast ensembles are overdispersive, implying that the real world is more predictable than indicated by estimates of so-called perfect model predictability, particularly over the North Atlantic. However, such estimates are based on relatively...
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ftpubmed:oai:pubmedcentral.nih.gov:4459196 2023-05-15T17:29:27+02:00 Impact of hindcast length on estimates of seasonal climate predictability Shi, W Schaller, N MacLeod, D Palmer, T N Weisheimer, A 2015-03-16 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4459196/ https://doi.org/10.1002/2014GL062829 en eng Blackwell Publishing Ltd http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4459196/ http://dx.doi.org/10.1002/2014GL062829 ©2015. The Authors. http://creativecommons.org/licenses/by/4.0/ This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. CC-BY Research Letters Text 2015 ftpubmed https://doi.org/10.1002/2014GL062829 2015-06-14T00:13:50Z It has recently been argued that single-model seasonal forecast ensembles are overdispersive, implying that the real world is more predictable than indicated by estimates of so-called perfect model predictability, particularly over the North Atlantic. However, such estimates are based on relatively short forecast data sets comprising just 20 years of seasonal predictions. Here we study longer 40 year seasonal forecast data sets from multimodel seasonal forecast ensemble projects and show that sampling uncertainty due to the length of the hindcast periods is large. The skill of forecasting the North Atlantic Oscillation during winter varies within the 40 year data sets with high levels of skill found for some subperiods. It is demonstrated that while 20 year estimates of seasonal reliability can show evidence of overdispersive behavior, the 40 year estimates are more stable and show no evidence of overdispersion. Instead, the predominant feature on these longer time scales is underdispersion, particularly in the tropics. Text North Atlantic North Atlantic oscillation PubMed Central (PMC) Geophysical Research Letters 42 5 1554 1559 |
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Research Letters Shi, W Schaller, N MacLeod, D Palmer, T N Weisheimer, A Impact of hindcast length on estimates of seasonal climate predictability |
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Research Letters |
description |
It has recently been argued that single-model seasonal forecast ensembles are overdispersive, implying that the real world is more predictable than indicated by estimates of so-called perfect model predictability, particularly over the North Atlantic. However, such estimates are based on relatively short forecast data sets comprising just 20 years of seasonal predictions. Here we study longer 40 year seasonal forecast data sets from multimodel seasonal forecast ensemble projects and show that sampling uncertainty due to the length of the hindcast periods is large. The skill of forecasting the North Atlantic Oscillation during winter varies within the 40 year data sets with high levels of skill found for some subperiods. It is demonstrated that while 20 year estimates of seasonal reliability can show evidence of overdispersive behavior, the 40 year estimates are more stable and show no evidence of overdispersion. Instead, the predominant feature on these longer time scales is underdispersion, particularly in the tropics. |
format |
Text |
author |
Shi, W Schaller, N MacLeod, D Palmer, T N Weisheimer, A |
author_facet |
Shi, W Schaller, N MacLeod, D Palmer, T N Weisheimer, A |
author_sort |
Shi, W |
title |
Impact of hindcast length on estimates of seasonal climate predictability |
title_short |
Impact of hindcast length on estimates of seasonal climate predictability |
title_full |
Impact of hindcast length on estimates of seasonal climate predictability |
title_fullStr |
Impact of hindcast length on estimates of seasonal climate predictability |
title_full_unstemmed |
Impact of hindcast length on estimates of seasonal climate predictability |
title_sort |
impact of hindcast length on estimates of seasonal climate predictability |
publisher |
Blackwell Publishing Ltd |
publishDate |
2015 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4459196/ https://doi.org/10.1002/2014GL062829 |
genre |
North Atlantic North Atlantic oscillation |
genre_facet |
North Atlantic North Atlantic oscillation |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4459196/ http://dx.doi.org/10.1002/2014GL062829 |
op_rights |
©2015. The Authors. http://creativecommons.org/licenses/by/4.0/ This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1002/2014GL062829 |
container_title |
Geophysical Research Letters |
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42 |
container_issue |
5 |
container_start_page |
1554 |
op_container_end_page |
1559 |
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1766123577164169216 |