North Atlantic warming: patterns of long-term trend and multidecadal variability
Ocean have wide-spread implications for Europe, Africa, and the Americas. This study assesses the relative contri-bution of the long-term trend and variability of North Atlantic warming using EOF analysis of deep-ocean and near-surface observations. Our analysis demonstrates that the recent warming...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.624.6762 2023-05-15T17:25:34+02:00 North Atlantic warming: patterns of long-term trend and multidecadal variability Xiangdong Zhang The Pennsylvania State University CiteSeerX Archives 2008 application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.624.6762 http://www2.gi.alaska.edu/~bhatt/publications/polyakovetal_2010.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.624.6762 http://www2.gi.alaska.edu/~bhatt/publications/polyakovetal_2010.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://www2.gi.alaska.edu/~bhatt/publications/polyakovetal_2010.pdf Substantial North Atlantic climate changes have occurred over recent decades (e.g. Levitus et al. 20 text 2008 ftciteseerx 2016-01-08T15:09:57Z Ocean have wide-spread implications for Europe, Africa, and the Americas. This study assesses the relative contri-bution of the long-term trend and variability of North Atlantic warming using EOF analysis of deep-ocean and near-surface observations. Our analysis demonstrates that the recent warming over the North Atlantic is linked to both long-term (including anthropogenic and natural) cli-mate change and multidecadal variability (MDV, *50– 80 years). Our results suggest a general warming trend of 0.031 ± 0.006"C/decade in the upper 2,000 m North Atlantic over the last 80 years of the twentieth century, although during this time there are periods in which short-term trends were strongly amplified by MDV. For example, MDV accounts for*60 % of North Atlantic warming since 1970. The single-sign basin-scale pattern of MDV with prolonged periods of warming (cooling) in the upper ocean layer and opposite tendency in the lower layer is evident from observations. This pattern is associated with a slow-down (enhancement) of the North Atlantic thermohaline overturning circulation during negative (positive) MDV phases. In contrast, the long-term trend exhibits warming in tropical and mid-latitude North Atlantic and a pattern of cooling in regions associated with major northward heat transports, consistent with a slowdown of the North Atlantic circulation as evident from observations and confirmed by selected modeling results. This localized cooling has been masked in recent decades by warming during the positive phase of MDV. Finally, since the North Atlantic Ocean plays a crucial role in establishing and regulating the global thermohaline circulation, the multi-decadal fluctuations discussed here should be considered when assessing long-term climate change and variability, both in the North Atlantic and at global scales. Text North Atlantic Unknown |
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Substantial North Atlantic climate changes have occurred over recent decades (e.g. Levitus et al. 20 |
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Substantial North Atlantic climate changes have occurred over recent decades (e.g. Levitus et al. 20 Xiangdong Zhang North Atlantic warming: patterns of long-term trend and multidecadal variability |
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Substantial North Atlantic climate changes have occurred over recent decades (e.g. Levitus et al. 20 |
description |
Ocean have wide-spread implications for Europe, Africa, and the Americas. This study assesses the relative contri-bution of the long-term trend and variability of North Atlantic warming using EOF analysis of deep-ocean and near-surface observations. Our analysis demonstrates that the recent warming over the North Atlantic is linked to both long-term (including anthropogenic and natural) cli-mate change and multidecadal variability (MDV, *50– 80 years). Our results suggest a general warming trend of 0.031 ± 0.006"C/decade in the upper 2,000 m North Atlantic over the last 80 years of the twentieth century, although during this time there are periods in which short-term trends were strongly amplified by MDV. For example, MDV accounts for*60 % of North Atlantic warming since 1970. The single-sign basin-scale pattern of MDV with prolonged periods of warming (cooling) in the upper ocean layer and opposite tendency in the lower layer is evident from observations. This pattern is associated with a slow-down (enhancement) of the North Atlantic thermohaline overturning circulation during negative (positive) MDV phases. In contrast, the long-term trend exhibits warming in tropical and mid-latitude North Atlantic and a pattern of cooling in regions associated with major northward heat transports, consistent with a slowdown of the North Atlantic circulation as evident from observations and confirmed by selected modeling results. This localized cooling has been masked in recent decades by warming during the positive phase of MDV. Finally, since the North Atlantic Ocean plays a crucial role in establishing and regulating the global thermohaline circulation, the multi-decadal fluctuations discussed here should be considered when assessing long-term climate change and variability, both in the North Atlantic and at global scales. |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
Xiangdong Zhang |
author_facet |
Xiangdong Zhang |
author_sort |
Xiangdong Zhang |
title |
North Atlantic warming: patterns of long-term trend and multidecadal variability |
title_short |
North Atlantic warming: patterns of long-term trend and multidecadal variability |
title_full |
North Atlantic warming: patterns of long-term trend and multidecadal variability |
title_fullStr |
North Atlantic warming: patterns of long-term trend and multidecadal variability |
title_full_unstemmed |
North Atlantic warming: patterns of long-term trend and multidecadal variability |
title_sort |
north atlantic warming: patterns of long-term trend and multidecadal variability |
publishDate |
2008 |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.624.6762 http://www2.gi.alaska.edu/~bhatt/publications/polyakovetal_2010.pdf |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
http://www2.gi.alaska.edu/~bhatt/publications/polyakovetal_2010.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.624.6762 http://www2.gi.alaska.edu/~bhatt/publications/polyakovetal_2010.pdf |
op_rights |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
_version_ |
1766117040860430336 |