Granger causality of coupled climate processes: Ocean feedback on the North Atlantic oscillation
This study uses a Granger causality time series modeling approach to quantitatively diagnose the feedback of daily sea surface temperatures (SSTs) on daily values of the North Atlantic Oscillation (NAO) as simulated by a realistic coupled general circulation model (GCM). Bivariate vector autoregress...
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ftunivreading:oai:centaur.reading.ac.uk:5246 2024-06-23T07:55:04+00:00 Granger causality of coupled climate processes: Ocean feedback on the North Atlantic oscillation Mosedale, T. J. Stephenson, D. B. Collins, M. Mills, T. C. 2006 https://centaur.reading.ac.uk/5246/ unknown American Meteorological Society Mosedale, T. J., Stephenson, D. B., Collins, M. and Mills, T. C. (2006) Granger causality of coupled climate processes: Ocean feedback on the North Atlantic oscillation. Journal Of Climate, 19 (7). pp. 1182-1194. ISSN 1520-0442 551 Geology hydrology meteorology Article NonPeerReviewed 2006 ftunivreading 2024-06-11T14:41:45Z This study uses a Granger causality time series modeling approach to quantitatively diagnose the feedback of daily sea surface temperatures (SSTs) on daily values of the North Atlantic Oscillation (NAO) as simulated by a realistic coupled general circulation model (GCM). Bivariate vector autoregressive time series models are carefully fitted to daily wintertime SST and NAO time series produced by a 50-yr simulation of the Third Hadley Centre Coupled Ocean-Atmosphere GCM (HadCM3). The approach demonstrates that there is a small yet statistically significant feedback of SSTs oil the NAO. The SST tripole index is found to provide additional predictive information for the NAO than that available by using only past values of NAO-the SST tripole is Granger causal for the NAO. Careful examination of local SSTs reveals that much of this effect is due to the effect of SSTs in the region of the Gulf Steam, especially south of Cape Hatteras. The effect of SSTs on NAO is responsible for the slower-than-exponential decay in lag-autocorrelations of NAO notable at lags longer than 10 days. The persistence induced in daily NAO by SSTs causes long-term means of NAO to have more variance than expected from averaging NAO noise if there is no feedback of the ocean on the atmosphere. There are greater long-term trends in NAO than can be expected from aggregating just short-term atmospheric noise, and NAO is potentially predictable provided that future SSTs are known. For example, there is about 10%-30% more variance in seasonal wintertime means of NAO and almost 70% more variance in annual means of NAO due to SST effects than one would expect if NAO were a purely atmospheric process. Article in Journal/Newspaper North Atlantic North Atlantic oscillation CentAUR: Central Archive at the University of Reading |
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CentAUR: Central Archive at the University of Reading |
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551 Geology hydrology meteorology |
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551 Geology hydrology meteorology Mosedale, T. J. Stephenson, D. B. Collins, M. Mills, T. C. Granger causality of coupled climate processes: Ocean feedback on the North Atlantic oscillation |
topic_facet |
551 Geology hydrology meteorology |
description |
This study uses a Granger causality time series modeling approach to quantitatively diagnose the feedback of daily sea surface temperatures (SSTs) on daily values of the North Atlantic Oscillation (NAO) as simulated by a realistic coupled general circulation model (GCM). Bivariate vector autoregressive time series models are carefully fitted to daily wintertime SST and NAO time series produced by a 50-yr simulation of the Third Hadley Centre Coupled Ocean-Atmosphere GCM (HadCM3). The approach demonstrates that there is a small yet statistically significant feedback of SSTs oil the NAO. The SST tripole index is found to provide additional predictive information for the NAO than that available by using only past values of NAO-the SST tripole is Granger causal for the NAO. Careful examination of local SSTs reveals that much of this effect is due to the effect of SSTs in the region of the Gulf Steam, especially south of Cape Hatteras. The effect of SSTs on NAO is responsible for the slower-than-exponential decay in lag-autocorrelations of NAO notable at lags longer than 10 days. The persistence induced in daily NAO by SSTs causes long-term means of NAO to have more variance than expected from averaging NAO noise if there is no feedback of the ocean on the atmosphere. There are greater long-term trends in NAO than can be expected from aggregating just short-term atmospheric noise, and NAO is potentially predictable provided that future SSTs are known. For example, there is about 10%-30% more variance in seasonal wintertime means of NAO and almost 70% more variance in annual means of NAO due to SST effects than one would expect if NAO were a purely atmospheric process. |
format |
Article in Journal/Newspaper |
author |
Mosedale, T. J. Stephenson, D. B. Collins, M. Mills, T. C. |
author_facet |
Mosedale, T. J. Stephenson, D. B. Collins, M. Mills, T. C. |
author_sort |
Mosedale, T. J. |
title |
Granger causality of coupled climate processes: Ocean feedback on the North Atlantic oscillation |
title_short |
Granger causality of coupled climate processes: Ocean feedback on the North Atlantic oscillation |
title_full |
Granger causality of coupled climate processes: Ocean feedback on the North Atlantic oscillation |
title_fullStr |
Granger causality of coupled climate processes: Ocean feedback on the North Atlantic oscillation |
title_full_unstemmed |
Granger causality of coupled climate processes: Ocean feedback on the North Atlantic oscillation |
title_sort |
granger causality of coupled climate processes: ocean feedback on the north atlantic oscillation |
publisher |
American Meteorological Society |
publishDate |
2006 |
url |
https://centaur.reading.ac.uk/5246/ |
genre |
North Atlantic North Atlantic oscillation |
genre_facet |
North Atlantic North Atlantic oscillation |
op_relation |
Mosedale, T. J., Stephenson, D. B., Collins, M. and Mills, T. C. (2006) Granger causality of coupled climate processes: Ocean feedback on the North Atlantic oscillation. Journal Of Climate, 19 (7). pp. 1182-1194. ISSN 1520-0442 |
_version_ |
1802647472112140288 |