Multidecadal Variability and Predictability of Antarctic Sea Ice in GFDL SPEAR_LO Model
Using a state-of-the-art coupled general circulation model, physical processes underlying Antarctic sea ice multidecadal variability and predictability are investigated. Our model simulations constrained with atmospheric reanalysis and observed sea surface temperature broadly capture the observed se...
Main Authors: | , , , , , , |
---|---|
Format: | Text |
Language: | English |
Published: |
2023
|
Subjects: | |
Online Access: | https://doi.org/10.5194/tc-2023-18 https://tc.copernicus.org/preprints/tc-2023-18/ |
id |
ftcopernicus:oai:publications.copernicus.org:tcd109367 |
---|---|
record_format |
openpolar |
spelling |
ftcopernicus:oai:publications.copernicus.org:tcd109367 2023-05-15T13:38:41+02:00 Multidecadal Variability and Predictability of Antarctic Sea Ice in GFDL SPEAR_LO Model Morioka, Yushi Zhang, Liping Delworth, Thomas Yang, Xiaosong Zeng, Fanrong Nonaka, Masami Behera, Swadhin 2023-02-28 application/pdf https://doi.org/10.5194/tc-2023-18 https://tc.copernicus.org/preprints/tc-2023-18/ eng eng doi:10.5194/tc-2023-18 https://tc.copernicus.org/preprints/tc-2023-18/ eISSN: 1994-0424 Text 2023 ftcopernicus https://doi.org/10.5194/tc-2023-18 2023-03-06T17:23:11Z Using a state-of-the-art coupled general circulation model, physical processes underlying Antarctic sea ice multidecadal variability and predictability are investigated. Our model simulations constrained with atmospheric reanalysis and observed sea surface temperature broadly capture the observed sea ice extent (SIE) variability with a low sea ice state (late 1970s–1990s) and a high sea ice state (2000s–early 2010s), although the model overestimates the SIE decrease over the Weddell Sea around the 1980s. The low sea ice state is largely due to an occurrence of strong deep convection in the Southern Ocean that subsequently induces anomalous warming of the upper ocean. During the high sea ice period (post-2000s), the deep convection substantially weakens, so that surface wind variability plays greater roles in the SIE variability. Decadal retrospective forecasts started from the above-mentioned constrained model results demonstrate that the Antarctic sea ice multidecadal variability can be skillfully predicted 6–10 years in advance, showing a moderate correlation with the observation (0.4). Ensemble members with a stronger deep convection tend to predict a larger sea ice decrease in the 1980s, whereas the members with a larger surface wind variability tend to predict a larger sea ice increase after the 2000s. Therefore, skillful simulation and prediction of the Antarctic sea ice multidecadal variability require accurate simulation and prediction of both the Southern Ocean deep convection and surface wind variability in the model. Text Antarc* Antarctic Sea ice Southern Ocean Weddell Sea Copernicus Publications: E-Journals Antarctic Southern Ocean The Antarctic Weddell Weddell Sea |
institution |
Open Polar |
collection |
Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
Using a state-of-the-art coupled general circulation model, physical processes underlying Antarctic sea ice multidecadal variability and predictability are investigated. Our model simulations constrained with atmospheric reanalysis and observed sea surface temperature broadly capture the observed sea ice extent (SIE) variability with a low sea ice state (late 1970s–1990s) and a high sea ice state (2000s–early 2010s), although the model overestimates the SIE decrease over the Weddell Sea around the 1980s. The low sea ice state is largely due to an occurrence of strong deep convection in the Southern Ocean that subsequently induces anomalous warming of the upper ocean. During the high sea ice period (post-2000s), the deep convection substantially weakens, so that surface wind variability plays greater roles in the SIE variability. Decadal retrospective forecasts started from the above-mentioned constrained model results demonstrate that the Antarctic sea ice multidecadal variability can be skillfully predicted 6–10 years in advance, showing a moderate correlation with the observation (0.4). Ensemble members with a stronger deep convection tend to predict a larger sea ice decrease in the 1980s, whereas the members with a larger surface wind variability tend to predict a larger sea ice increase after the 2000s. Therefore, skillful simulation and prediction of the Antarctic sea ice multidecadal variability require accurate simulation and prediction of both the Southern Ocean deep convection and surface wind variability in the model. |
format |
Text |
author |
Morioka, Yushi Zhang, Liping Delworth, Thomas Yang, Xiaosong Zeng, Fanrong Nonaka, Masami Behera, Swadhin |
spellingShingle |
Morioka, Yushi Zhang, Liping Delworth, Thomas Yang, Xiaosong Zeng, Fanrong Nonaka, Masami Behera, Swadhin Multidecadal Variability and Predictability of Antarctic Sea Ice in GFDL SPEAR_LO Model |
author_facet |
Morioka, Yushi Zhang, Liping Delworth, Thomas Yang, Xiaosong Zeng, Fanrong Nonaka, Masami Behera, Swadhin |
author_sort |
Morioka, Yushi |
title |
Multidecadal Variability and Predictability of Antarctic Sea Ice in GFDL SPEAR_LO Model |
title_short |
Multidecadal Variability and Predictability of Antarctic Sea Ice in GFDL SPEAR_LO Model |
title_full |
Multidecadal Variability and Predictability of Antarctic Sea Ice in GFDL SPEAR_LO Model |
title_fullStr |
Multidecadal Variability and Predictability of Antarctic Sea Ice in GFDL SPEAR_LO Model |
title_full_unstemmed |
Multidecadal Variability and Predictability of Antarctic Sea Ice in GFDL SPEAR_LO Model |
title_sort |
multidecadal variability and predictability of antarctic sea ice in gfdl spear_lo model |
publishDate |
2023 |
url |
https://doi.org/10.5194/tc-2023-18 https://tc.copernicus.org/preprints/tc-2023-18/ |
geographic |
Antarctic Southern Ocean The Antarctic Weddell Weddell Sea |
geographic_facet |
Antarctic Southern Ocean The Antarctic Weddell Weddell Sea |
genre |
Antarc* Antarctic Sea ice Southern Ocean Weddell Sea |
genre_facet |
Antarc* Antarctic Sea ice Southern Ocean Weddell Sea |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-2023-18 https://tc.copernicus.org/preprints/tc-2023-18/ |
op_doi |
https://doi.org/10.5194/tc-2023-18 |
_version_ |
1766109912178360320 |