An enhancement of low-frequency variability in the Kuroshio–Oyashio Extension in CCSM3 owing to ocean model biases
Author Posting. © American Meteorological Society, 2010. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Climate 23 (2010): 6221–6233, doi:10.1175/2010JCLI3402.1. Enhanced decada...
Published in: | Journal of Climate |
---|---|
Main Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
American Meteorological Society
2010
|
Subjects: | |
Online Access: | https://hdl.handle.net/1912/4325 |
id |
ftwhoas:oai:darchive.mblwhoilibrary.org:1912/4325 |
---|---|
record_format |
openpolar |
spelling |
ftwhoas:oai:darchive.mblwhoilibrary.org:1912/4325 2023-05-15T18:28:39+02:00 An enhancement of low-frequency variability in the Kuroshio–Oyashio Extension in CCSM3 owing to ocean model biases Thompson, LuAnne Kwon, Young-Oh 2010-12-01 application/pdf https://hdl.handle.net/1912/4325 en_US eng American Meteorological Society https://doi.org/10.1175/2010JCLI3402.1 Journal of Climate 23 (2010): 6221–6233 https://hdl.handle.net/1912/4325 doi:10.1175/2010JCLI3402.1 Journal of Climate 23 (2010): 6221–6233 doi:10.1175/2010JCLI3402.1 Bias Coupled models Decadal variability Ocean models Sea surface temperature Wind stress Article 2010 ftwhoas https://doi.org/10.1175/2010JCLI3402.1 2022-05-28T22:58:16Z Author Posting. © American Meteorological Society, 2010. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Climate 23 (2010): 6221–6233, doi:10.1175/2010JCLI3402.1. Enhanced decadal variability in sea surface temperature (SST) centered on the Kuroshio Extension (KE) has been found in the Community Climate System Model version 3 (CCSM3) as well as in other coupled climate models. This decadal peak has higher energy than is found in nature, almost twice as large in some cases. While previous analyses have concentrated on the mechanisms for such decadal variability in coupled models, an analysis of the causes of excessive SST response to changes in wind stress has been missing. Here, a detailed comparison of the relationships between interannual changes in SST and sea surface height (SSH) as a proxy for geostrophic surface currents in the region in both CCSM3 and observations, and how these relationships depend on the mean ocean circulation, temperature, and salinity, is made. We use observationally based climatological temperature and salinity fields as well as satellite-based SSH and SST fields for comparison. The primary cause for the excessive SST variability is the coincidence of the mean KE with the region of largest SST gradients in the model. In observations, these two regions are separated by almost 500 km. In addition, the too shallow surface oceanic mixed layer in March north of the KE in the subarctic Pacific contributes to the biases. These biases are not unique to CCSM3 and suggest that mean biases in current, temperature, and salinity structures in separated western boundary current regions can exert a large influence on the size of modeled decadal SST variability. Support for L.T. was provided by the NASA sponsored Ocean Surface Topography Science Team, under Contract 1267196 with the University of Washington, administered by the Jet Propulsion Laboratory. Support for Y.-O. K. ... Article in Journal/Newspaper Subarctic Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) Oyashio ENVELOPE(157.000,157.000,50.000,50.000) Pacific Journal of Climate 23 23 6221 6233 |
institution |
Open Polar |
collection |
Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) |
op_collection_id |
ftwhoas |
language |
English |
topic |
Bias Coupled models Decadal variability Ocean models Sea surface temperature Wind stress |
spellingShingle |
Bias Coupled models Decadal variability Ocean models Sea surface temperature Wind stress Thompson, LuAnne Kwon, Young-Oh An enhancement of low-frequency variability in the Kuroshio–Oyashio Extension in CCSM3 owing to ocean model biases |
topic_facet |
Bias Coupled models Decadal variability Ocean models Sea surface temperature Wind stress |
description |
Author Posting. © American Meteorological Society, 2010. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Climate 23 (2010): 6221–6233, doi:10.1175/2010JCLI3402.1. Enhanced decadal variability in sea surface temperature (SST) centered on the Kuroshio Extension (KE) has been found in the Community Climate System Model version 3 (CCSM3) as well as in other coupled climate models. This decadal peak has higher energy than is found in nature, almost twice as large in some cases. While previous analyses have concentrated on the mechanisms for such decadal variability in coupled models, an analysis of the causes of excessive SST response to changes in wind stress has been missing. Here, a detailed comparison of the relationships between interannual changes in SST and sea surface height (SSH) as a proxy for geostrophic surface currents in the region in both CCSM3 and observations, and how these relationships depend on the mean ocean circulation, temperature, and salinity, is made. We use observationally based climatological temperature and salinity fields as well as satellite-based SSH and SST fields for comparison. The primary cause for the excessive SST variability is the coincidence of the mean KE with the region of largest SST gradients in the model. In observations, these two regions are separated by almost 500 km. In addition, the too shallow surface oceanic mixed layer in March north of the KE in the subarctic Pacific contributes to the biases. These biases are not unique to CCSM3 and suggest that mean biases in current, temperature, and salinity structures in separated western boundary current regions can exert a large influence on the size of modeled decadal SST variability. Support for L.T. was provided by the NASA sponsored Ocean Surface Topography Science Team, under Contract 1267196 with the University of Washington, administered by the Jet Propulsion Laboratory. Support for Y.-O. K. ... |
format |
Article in Journal/Newspaper |
author |
Thompson, LuAnne Kwon, Young-Oh |
author_facet |
Thompson, LuAnne Kwon, Young-Oh |
author_sort |
Thompson, LuAnne |
title |
An enhancement of low-frequency variability in the Kuroshio–Oyashio Extension in CCSM3 owing to ocean model biases |
title_short |
An enhancement of low-frequency variability in the Kuroshio–Oyashio Extension in CCSM3 owing to ocean model biases |
title_full |
An enhancement of low-frequency variability in the Kuroshio–Oyashio Extension in CCSM3 owing to ocean model biases |
title_fullStr |
An enhancement of low-frequency variability in the Kuroshio–Oyashio Extension in CCSM3 owing to ocean model biases |
title_full_unstemmed |
An enhancement of low-frequency variability in the Kuroshio–Oyashio Extension in CCSM3 owing to ocean model biases |
title_sort |
enhancement of low-frequency variability in the kuroshio–oyashio extension in ccsm3 owing to ocean model biases |
publisher |
American Meteorological Society |
publishDate |
2010 |
url |
https://hdl.handle.net/1912/4325 |
long_lat |
ENVELOPE(157.000,157.000,50.000,50.000) |
geographic |
Oyashio Pacific |
geographic_facet |
Oyashio Pacific |
genre |
Subarctic |
genre_facet |
Subarctic |
op_source |
Journal of Climate 23 (2010): 6221–6233 doi:10.1175/2010JCLI3402.1 |
op_relation |
https://doi.org/10.1175/2010JCLI3402.1 Journal of Climate 23 (2010): 6221–6233 https://hdl.handle.net/1912/4325 doi:10.1175/2010JCLI3402.1 |
op_doi |
https://doi.org/10.1175/2010JCLI3402.1 |
container_title |
Journal of Climate |
container_volume |
23 |
container_issue |
23 |
container_start_page |
6221 |
op_container_end_page |
6233 |
_version_ |
1766211205811142656 |