Tropical Atlantic rainfall drives bias in extratropical seasonal forecasts
Abstract We investigate the impact of seasonal forecast biases in the Tropical Atlantic on the North Atlantic. The analysis uses a novel ensemble‐based method to estimate the impact of tropical rainfall bias on forecasts of the Extratropical North Atlantic. The inter‐ensemble spread of the forecast...
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Online Access: | http://dx.doi.org/10.1002/asl.1205 https://rmets.onlinelibrary.wiley.com/doi/pdf/10.1002/asl.1205 |
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crwiley:10.1002/asl.1205 2024-06-02T08:10:59+00:00 Tropical Atlantic rainfall drives bias in extratropical seasonal forecasts Collier, T. Kettleborough, J. Scaife, A. A. Hermanson, L. Davis, P. 2023 http://dx.doi.org/10.1002/asl.1205 https://rmets.onlinelibrary.wiley.com/doi/pdf/10.1002/asl.1205 en eng Wiley http://creativecommons.org/licenses/by/4.0/ Atmospheric Science Letters volume 25, issue 4 ISSN 1530-261X 1530-261X journal-article 2023 crwiley https://doi.org/10.1002/asl.1205 2024-05-03T11:41:16Z Abstract We investigate the impact of seasonal forecast biases in the Tropical Atlantic on the North Atlantic. The analysis uses a novel ensemble‐based method to estimate the impact of tropical rainfall bias on forecasts of the Extratropical North Atlantic. The inter‐ensemble spread of the forecast model is used to estimate the impact of the bias in Tropical Atlantic rainfall on the North Atlantic by selecting model members that happen to produce forecast anomalies that most closely resemble the tropical rainfall bias and using these as a proxy for the model error. The Tropical Atlantic rainfall bias impacts Rossby wave sources over the Subtropical Atlantic and there is a clear Rossby wave pattern originating from this area which is comparable to the mean bias in hindcasts. We argue that Tropical Atlantic rainfall errors explain a significant amount of the bias in seasonal forecasts over the Extratropical North Atlantic. Article in Journal/Newspaper North Atlantic Wiley Online Library Atmospheric Science Letters |
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Open Polar |
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Wiley Online Library |
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crwiley |
language |
English |
description |
Abstract We investigate the impact of seasonal forecast biases in the Tropical Atlantic on the North Atlantic. The analysis uses a novel ensemble‐based method to estimate the impact of tropical rainfall bias on forecasts of the Extratropical North Atlantic. The inter‐ensemble spread of the forecast model is used to estimate the impact of the bias in Tropical Atlantic rainfall on the North Atlantic by selecting model members that happen to produce forecast anomalies that most closely resemble the tropical rainfall bias and using these as a proxy for the model error. The Tropical Atlantic rainfall bias impacts Rossby wave sources over the Subtropical Atlantic and there is a clear Rossby wave pattern originating from this area which is comparable to the mean bias in hindcasts. We argue that Tropical Atlantic rainfall errors explain a significant amount of the bias in seasonal forecasts over the Extratropical North Atlantic. |
format |
Article in Journal/Newspaper |
author |
Collier, T. Kettleborough, J. Scaife, A. A. Hermanson, L. Davis, P. |
spellingShingle |
Collier, T. Kettleborough, J. Scaife, A. A. Hermanson, L. Davis, P. Tropical Atlantic rainfall drives bias in extratropical seasonal forecasts |
author_facet |
Collier, T. Kettleborough, J. Scaife, A. A. Hermanson, L. Davis, P. |
author_sort |
Collier, T. |
title |
Tropical Atlantic rainfall drives bias in extratropical seasonal forecasts |
title_short |
Tropical Atlantic rainfall drives bias in extratropical seasonal forecasts |
title_full |
Tropical Atlantic rainfall drives bias in extratropical seasonal forecasts |
title_fullStr |
Tropical Atlantic rainfall drives bias in extratropical seasonal forecasts |
title_full_unstemmed |
Tropical Atlantic rainfall drives bias in extratropical seasonal forecasts |
title_sort |
tropical atlantic rainfall drives bias in extratropical seasonal forecasts |
publisher |
Wiley |
publishDate |
2023 |
url |
http://dx.doi.org/10.1002/asl.1205 https://rmets.onlinelibrary.wiley.com/doi/pdf/10.1002/asl.1205 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Atmospheric Science Letters volume 25, issue 4 ISSN 1530-261X 1530-261X |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1002/asl.1205 |
container_title |
Atmospheric Science Letters |
_version_ |
1800756939901108224 |