Assessing the secular variability of turbulent mixing in the Southern ocean
The Southern Ocean is a huge reservoir of negative heat and substances such as CO 2 , and plays a key role in global climate change. Turbulent mixing is thought to be responsible for changes in the physical circulation field, such as the recently discovered shallowing of the meridional circulation i...
Main Authors: | , , |
---|---|
Format: | Conference Object |
Language: | English |
Published: |
2023
|
Subjects: | |
Online Access: | https://gfzpublic.gfz-potsdam.de/pubman/item/item_5018400 |
id |
ftgfzpotsdam:oai:gfzpublic.gfz-potsdam.de:item_5018400 |
---|---|
record_format |
openpolar |
spelling |
ftgfzpotsdam:oai:gfzpublic.gfz-potsdam.de:item_5018400 2023-07-02T03:33:45+02:00 Assessing the secular variability of turbulent mixing in the Southern ocean Kitade, Y. Naho, K. Toshiyuki, H. 2023 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5018400 eng eng info:eu-repo/semantics/altIdentifier/doi/10.57757/IUGG23-2357 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5018400 XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) info:eu-repo/semantics/conferenceObject 2023 ftgfzpotsdam https://doi.org/10.57757/IUGG23-2357 2023-06-11T23:39:54Z The Southern Ocean is a huge reservoir of negative heat and substances such as CO 2 , and plays a key role in global climate change. Turbulent mixing is thought to be responsible for changes in the physical circulation field, such as the recently discovered shallowing of the meridional circulation in the Southern Ocean (Shimada et al., 2022), in addition to its contribution to the biological system, such as the supply of nutrients. We analyze CTD data collected by the T/V Umitaka Maru along the 110°E longitude of the Southern Ocean over a period of 10 years (from 2011 to 2020) and turbulence data collected by the VMP-5500 in 2016, and investigate the distribution and variability of vertical mixing. We characterize various turbulence parameters by applying the method of Galbraith and Kelly (1996) as well as the method of Gargett and Garner (2008) to the density inversion of the CTD data and deriving the calibration coefficients from the VMP-5500 data. Based on the obtained parameters, we evaluate the distribution and secular variation of turbulent mixing. We find a tendency of high turbulent mixing at high latitudes and a few strong turbulent mixing regions near the seafloor in the mid-ocean ridge and continental slope. As for the secular change, although there is almost no change in the turbulent diffusion coefficient from the deep layer to the seafloor, an increasing trend with a rate of about one order in 10 years is found from the surface mixed layer to the halocline. Conference Object Southern Ocean GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam) Southern Ocean |
institution |
Open Polar |
collection |
GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam) |
op_collection_id |
ftgfzpotsdam |
language |
English |
description |
The Southern Ocean is a huge reservoir of negative heat and substances such as CO 2 , and plays a key role in global climate change. Turbulent mixing is thought to be responsible for changes in the physical circulation field, such as the recently discovered shallowing of the meridional circulation in the Southern Ocean (Shimada et al., 2022), in addition to its contribution to the biological system, such as the supply of nutrients. We analyze CTD data collected by the T/V Umitaka Maru along the 110°E longitude of the Southern Ocean over a period of 10 years (from 2011 to 2020) and turbulence data collected by the VMP-5500 in 2016, and investigate the distribution and variability of vertical mixing. We characterize various turbulence parameters by applying the method of Galbraith and Kelly (1996) as well as the method of Gargett and Garner (2008) to the density inversion of the CTD data and deriving the calibration coefficients from the VMP-5500 data. Based on the obtained parameters, we evaluate the distribution and secular variation of turbulent mixing. We find a tendency of high turbulent mixing at high latitudes and a few strong turbulent mixing regions near the seafloor in the mid-ocean ridge and continental slope. As for the secular change, although there is almost no change in the turbulent diffusion coefficient from the deep layer to the seafloor, an increasing trend with a rate of about one order in 10 years is found from the surface mixed layer to the halocline. |
format |
Conference Object |
author |
Kitade, Y. Naho, K. Toshiyuki, H. |
spellingShingle |
Kitade, Y. Naho, K. Toshiyuki, H. Assessing the secular variability of turbulent mixing in the Southern ocean |
author_facet |
Kitade, Y. Naho, K. Toshiyuki, H. |
author_sort |
Kitade, Y. |
title |
Assessing the secular variability of turbulent mixing in the Southern ocean |
title_short |
Assessing the secular variability of turbulent mixing in the Southern ocean |
title_full |
Assessing the secular variability of turbulent mixing in the Southern ocean |
title_fullStr |
Assessing the secular variability of turbulent mixing in the Southern ocean |
title_full_unstemmed |
Assessing the secular variability of turbulent mixing in the Southern ocean |
title_sort |
assessing the secular variability of turbulent mixing in the southern ocean |
publishDate |
2023 |
url |
https://gfzpublic.gfz-potsdam.de/pubman/item/item_5018400 |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_source |
XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.57757/IUGG23-2357 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5018400 |
op_doi |
https://doi.org/10.57757/IUGG23-2357 |
_version_ |
1770273832448294912 |