A mechanism of internal decadal atlantic ocean variability in a high-resolution coupled climate model
The North Atlantic Ocean subpolar gyre (NA SPG) is an important region for initialising decadal climate forecasts. Climate model simulations and palaeo climate reconstructions have indicated that this region could also exhibit large, internally generated variability on decadal timescales. Understand...
Published in: | Journal of Climate |
---|---|
Main Authors: | , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
American Meteorological Society
2015
|
Subjects: | |
Online Access: | https://centaur.reading.ac.uk/40809/ https://centaur.reading.ac.uk/40809/1/menary2015.pdf |
id |
ftunivreading:oai:centaur.reading.ac.uk:40809 |
---|---|
record_format |
openpolar |
spelling |
ftunivreading:oai:centaur.reading.ac.uk:40809 2024-06-23T07:54:26+00:00 A mechanism of internal decadal atlantic ocean variability in a high-resolution coupled climate model Menary, Matthew B. Hodson, Daniel L. R. Robson, Jon I. Sutton, Rowan T. Wood, Richard A. 2015-10 text https://centaur.reading.ac.uk/40809/ https://centaur.reading.ac.uk/40809/1/menary2015.pdf en eng American Meteorological Society https://centaur.reading.ac.uk/40809/1/menary2015.pdf Menary, M. B., Hodson, D. L. R. <https://centaur.reading.ac.uk/view/creators/90000306.html> orcid:0000-0001-7159-6700 , Robson, J. I. <https://centaur.reading.ac.uk/view/creators/90002607.html> orcid:0000-0002-3467-018X , Sutton, R. T. <https://centaur.reading.ac.uk/view/creators/90000057.html> orcid:0000-0001-8345-8583 and Wood, R. A. (2015) A mechanism of internal decadal atlantic ocean variability in a high-resolution coupled climate model. Journal of Climate, 28 (19). pp. 7764-7785. ISSN 1520-0442 doi: https://doi.org/10.1175/JCLI-D-15-0106.1 <https://doi.org/10.1175/JCLI-D-15-0106.1> Article PeerReviewed 2015 ftunivreading https://doi.org/10.1175/JCLI-D-15-0106.1 2024-06-11T15:04:44Z The North Atlantic Ocean subpolar gyre (NA SPG) is an important region for initialising decadal climate forecasts. Climate model simulations and palaeo climate reconstructions have indicated that this region could also exhibit large, internally generated variability on decadal timescales. Understanding these modes of variability, their consistency across models, and the conditions in which they exist, is clearly important for improving the skill of decadal predictions — particularly when these predictions are made with the same underlying climate models. Here we describe and analyse a mode of internal variability in the NA SPG in a state-of-the-art, high resolution, coupled climate model. This mode has a period of 17 years and explains 15–30% of the annual variance in related ocean indices. It arises due to the advection of heat content anomalies around the NA SPG. Anomalous circulation drives the variability in the southern half of the NA SPG, whilst mean circulation and anomalous temperatures are important in the northern half. A negative feedback between Labrador Sea temperatures/densities and those in the North Atlantic Current is identified, which allows for the phase reversal. The atmosphere is found to act as a positive feedback on to this mode via the North Atlantic Oscillation which itself exhibits a spectral peak at 17 years. Decadal ocean density changes associated with this mode are driven by variations in temperature, rather than salinity — a point which models often disagree on and which we suggest may affect the veracity of the underlying assumptions of anomaly-assimilating decadal prediction methodologies. Article in Journal/Newspaper Labrador Sea north atlantic current North Atlantic North Atlantic oscillation CentAUR: Central Archive at the University of Reading Journal of Climate 28 19 7764 7785 |
institution |
Open Polar |
collection |
CentAUR: Central Archive at the University of Reading |
op_collection_id |
ftunivreading |
language |
English |
description |
The North Atlantic Ocean subpolar gyre (NA SPG) is an important region for initialising decadal climate forecasts. Climate model simulations and palaeo climate reconstructions have indicated that this region could also exhibit large, internally generated variability on decadal timescales. Understanding these modes of variability, their consistency across models, and the conditions in which they exist, is clearly important for improving the skill of decadal predictions — particularly when these predictions are made with the same underlying climate models. Here we describe and analyse a mode of internal variability in the NA SPG in a state-of-the-art, high resolution, coupled climate model. This mode has a period of 17 years and explains 15–30% of the annual variance in related ocean indices. It arises due to the advection of heat content anomalies around the NA SPG. Anomalous circulation drives the variability in the southern half of the NA SPG, whilst mean circulation and anomalous temperatures are important in the northern half. A negative feedback between Labrador Sea temperatures/densities and those in the North Atlantic Current is identified, which allows for the phase reversal. The atmosphere is found to act as a positive feedback on to this mode via the North Atlantic Oscillation which itself exhibits a spectral peak at 17 years. Decadal ocean density changes associated with this mode are driven by variations in temperature, rather than salinity — a point which models often disagree on and which we suggest may affect the veracity of the underlying assumptions of anomaly-assimilating decadal prediction methodologies. |
format |
Article in Journal/Newspaper |
author |
Menary, Matthew B. Hodson, Daniel L. R. Robson, Jon I. Sutton, Rowan T. Wood, Richard A. |
spellingShingle |
Menary, Matthew B. Hodson, Daniel L. R. Robson, Jon I. Sutton, Rowan T. Wood, Richard A. A mechanism of internal decadal atlantic ocean variability in a high-resolution coupled climate model |
author_facet |
Menary, Matthew B. Hodson, Daniel L. R. Robson, Jon I. Sutton, Rowan T. Wood, Richard A. |
author_sort |
Menary, Matthew B. |
title |
A mechanism of internal decadal atlantic ocean variability in a high-resolution coupled climate model |
title_short |
A mechanism of internal decadal atlantic ocean variability in a high-resolution coupled climate model |
title_full |
A mechanism of internal decadal atlantic ocean variability in a high-resolution coupled climate model |
title_fullStr |
A mechanism of internal decadal atlantic ocean variability in a high-resolution coupled climate model |
title_full_unstemmed |
A mechanism of internal decadal atlantic ocean variability in a high-resolution coupled climate model |
title_sort |
mechanism of internal decadal atlantic ocean variability in a high-resolution coupled climate model |
publisher |
American Meteorological Society |
publishDate |
2015 |
url |
https://centaur.reading.ac.uk/40809/ https://centaur.reading.ac.uk/40809/1/menary2015.pdf |
genre |
Labrador Sea north atlantic current North Atlantic North Atlantic oscillation |
genre_facet |
Labrador Sea north atlantic current North Atlantic North Atlantic oscillation |
op_relation |
https://centaur.reading.ac.uk/40809/1/menary2015.pdf Menary, M. B., Hodson, D. L. R. <https://centaur.reading.ac.uk/view/creators/90000306.html> orcid:0000-0001-7159-6700 , Robson, J. I. <https://centaur.reading.ac.uk/view/creators/90002607.html> orcid:0000-0002-3467-018X , Sutton, R. T. <https://centaur.reading.ac.uk/view/creators/90000057.html> orcid:0000-0001-8345-8583 and Wood, R. A. (2015) A mechanism of internal decadal atlantic ocean variability in a high-resolution coupled climate model. Journal of Climate, 28 (19). pp. 7764-7785. ISSN 1520-0442 doi: https://doi.org/10.1175/JCLI-D-15-0106.1 <https://doi.org/10.1175/JCLI-D-15-0106.1> |
op_doi |
https://doi.org/10.1175/JCLI-D-15-0106.1 |
container_title |
Journal of Climate |
container_volume |
28 |
container_issue |
19 |
container_start_page |
7764 |
op_container_end_page |
7785 |
_version_ |
1802646589734387712 |