Atlantic Multidecadal Variability: Surface and Subsurface Thermohaline Structure and Hydroclimate Impacts
The Atlantic Multidecadal Oscillation (AMO), a sea surface temperature mode of natural variability with dominant timescales of 30 -70 years and largest variations centered on the northern North Atlantic latitudes is one of the principal climate signals that have earned considerable attention in the...
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ftunivmaryland:oai:drum.lib.umd.edu:1903/16072 2023-05-15T17:28:53+02:00 Atlantic Multidecadal Variability: Surface and Subsurface Thermohaline Structure and Hydroclimate Impacts Kavvada, Argyro Nigam, Sumant Ruiz-Barradas, Alfredo Digital Repository at the University of Maryland University of Maryland (College Park, Md.) Atmospheric and Oceanic Sciences 2014 application/pdf http://hdl.handle.net/1903/16072 https://doi.org/10.13016/M2FS5H en eng doi:10.13016/M2FS5H http://hdl.handle.net/1903/16072 Atmospheric sciences AMO Gulf Stream hydroclimate impacts NAO subsurface thermohaline Dissertation 2014 ftunivmaryland https://doi.org/10.13016/M2FS5H 2022-11-11T11:15:51Z The Atlantic Multidecadal Oscillation (AMO), a sea surface temperature mode of natural variability with dominant timescales of 30 -70 years and largest variations centered on the northern North Atlantic latitudes is one of the principal climate signals that have earned considerable attention in the recent decades, due to its multilateral impact on both local and remote weather and climate and its importance in predicting extreme events, such as drought development over North America. A 3-dimensional structure of the AMO is constructed based on observations and coupled, ocean-atmosphere 20th century climate simulations. The evolution of modeled, decadal-to-multidecadal variability and its hydroclimate impact is also investigated between two successive model versions participating in the CMIP3 and CMIP5 projects. It is found that both model versions underestimate low frequency variability in the 70-80 and 30-40 year ranges, while overestimating variability in higher frequencies (10-20 year range). In addition, no significant improvements are noted in the simulation of AMO's hydroclimate impact. A subsurface, vertically integrated heat content index (0-1000m) is proposed in an effort to capture the thermal state of the ocean and to understand the origin of AMO variability, especially its surface-subsurface link on decadal- to- multidecadal timescales in the North Atlantic basin. The AMO-HC index exhibits stronger oscillatory behavior and shorter timescales in comparison to the AMO-SST index, while leading the latter by about 5 years. A cooling of the North Atlantic subsurface is discernible in the recent years (mid-2000s -present), a feature that is almost absent at the ocean surface and could have tremendous implications in predicting future North Atlantic climate and in relation to the recent hiatus in the rise of global surface temperatures that was noted in the latest Intergovernmental Panel on Climate Change assessment report. Finally, AMO's decadal variability is shown linked to Gulf Stream's northward surges ... Doctoral or Postdoctoral Thesis North Atlantic University of Maryland: Digital Repository (DRUM) |
institution |
Open Polar |
collection |
University of Maryland: Digital Repository (DRUM) |
op_collection_id |
ftunivmaryland |
language |
English |
topic |
Atmospheric sciences AMO Gulf Stream hydroclimate impacts NAO subsurface thermohaline |
spellingShingle |
Atmospheric sciences AMO Gulf Stream hydroclimate impacts NAO subsurface thermohaline Kavvada, Argyro Atlantic Multidecadal Variability: Surface and Subsurface Thermohaline Structure and Hydroclimate Impacts |
topic_facet |
Atmospheric sciences AMO Gulf Stream hydroclimate impacts NAO subsurface thermohaline |
description |
The Atlantic Multidecadal Oscillation (AMO), a sea surface temperature mode of natural variability with dominant timescales of 30 -70 years and largest variations centered on the northern North Atlantic latitudes is one of the principal climate signals that have earned considerable attention in the recent decades, due to its multilateral impact on both local and remote weather and climate and its importance in predicting extreme events, such as drought development over North America. A 3-dimensional structure of the AMO is constructed based on observations and coupled, ocean-atmosphere 20th century climate simulations. The evolution of modeled, decadal-to-multidecadal variability and its hydroclimate impact is also investigated between two successive model versions participating in the CMIP3 and CMIP5 projects. It is found that both model versions underestimate low frequency variability in the 70-80 and 30-40 year ranges, while overestimating variability in higher frequencies (10-20 year range). In addition, no significant improvements are noted in the simulation of AMO's hydroclimate impact. A subsurface, vertically integrated heat content index (0-1000m) is proposed in an effort to capture the thermal state of the ocean and to understand the origin of AMO variability, especially its surface-subsurface link on decadal- to- multidecadal timescales in the North Atlantic basin. The AMO-HC index exhibits stronger oscillatory behavior and shorter timescales in comparison to the AMO-SST index, while leading the latter by about 5 years. A cooling of the North Atlantic subsurface is discernible in the recent years (mid-2000s -present), a feature that is almost absent at the ocean surface and could have tremendous implications in predicting future North Atlantic climate and in relation to the recent hiatus in the rise of global surface temperatures that was noted in the latest Intergovernmental Panel on Climate Change assessment report. Finally, AMO's decadal variability is shown linked to Gulf Stream's northward surges ... |
author2 |
Nigam, Sumant Ruiz-Barradas, Alfredo Digital Repository at the University of Maryland University of Maryland (College Park, Md.) Atmospheric and Oceanic Sciences |
format |
Doctoral or Postdoctoral Thesis |
author |
Kavvada, Argyro |
author_facet |
Kavvada, Argyro |
author_sort |
Kavvada, Argyro |
title |
Atlantic Multidecadal Variability: Surface and Subsurface Thermohaline Structure and Hydroclimate Impacts |
title_short |
Atlantic Multidecadal Variability: Surface and Subsurface Thermohaline Structure and Hydroclimate Impacts |
title_full |
Atlantic Multidecadal Variability: Surface and Subsurface Thermohaline Structure and Hydroclimate Impacts |
title_fullStr |
Atlantic Multidecadal Variability: Surface and Subsurface Thermohaline Structure and Hydroclimate Impacts |
title_full_unstemmed |
Atlantic Multidecadal Variability: Surface and Subsurface Thermohaline Structure and Hydroclimate Impacts |
title_sort |
atlantic multidecadal variability: surface and subsurface thermohaline structure and hydroclimate impacts |
publishDate |
2014 |
url |
http://hdl.handle.net/1903/16072 https://doi.org/10.13016/M2FS5H |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
doi:10.13016/M2FS5H http://hdl.handle.net/1903/16072 |
op_doi |
https://doi.org/10.13016/M2FS5H |
_version_ |
1766122021330092032 |