Spurious sea ice formation caused by oscillatory ocean tracer advection schemes
Tracer advection schemes used by ocean models are susceptible to artificial oscillations: a form of numerical error whereby the advected field alternates between overshooting and undershooting the exact solution, producing false extrema. Here we show that these oscillations have undesirable interact...
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ftunswworks:oai:unsworks.library.unsw.edu.au:1959.4/unsworks_58898 2024-05-19T07:29:01+00:00 Spurious sea ice formation caused by oscillatory ocean tracer advection schemes Naughten, KA Galton-Fenzi, BK Meissner, KJ England, MH Brassington, GB Colberg, F Hattermann, T Debernard, JB 2017-08-01 application/pdf http://hdl.handle.net/1959.4/unsworks_58898 https://unsworks.unsw.edu.au/bitstreams/50a8f21b-3870-45fd-9855-066b106c39e3/download https://doi.org/10.1016/j.ocemod.2017.06.010 unknown Elsevier http://hdl.handle.net/1959.4/unsworks_58898 https://unsworks.unsw.edu.au/bitstreams/50a8f21b-3870-45fd-9855-066b106c39e3/download https://doi.org/10.1016/j.ocemod.2017.06.010 open access https://purl.org/coar/access_right/c_abf2 CC-BY-NC-ND https://creativecommons.org/licenses/by-nc-nd/4.0/ free_to_read urn:ISSN:1463-5003 urn:ISSN:1463-5011 Ocean Modelling, 116, 108-117 14 Life Below Water anzsrc-for: 0405 Oceanography anzsrc-for: 0911 Maritime Engineering journal article http://purl.org/coar/resource_type/c_6501 2017 ftunswworks https://doi.org/10.1016/j.ocemod.2017.06.010 2024-04-24T00:33:11Z Tracer advection schemes used by ocean models are susceptible to artificial oscillations: a form of numerical error whereby the advected field alternates between overshooting and undershooting the exact solution, producing false extrema. Here we show that these oscillations have undesirable interactions with a coupled sea ice model. When oscillations cause the near-surface ocean temperature to fall below the freezing point, sea ice forms for no reason other than numerical error. This spurious sea ice formation has significant and wide-ranging impacts on Southern Ocean simulations, including the disappearance of coastal polynyas, stratification of the water column, erosion of Winter Water, and upwelling of warm Circumpolar Deep Water. This significantly limits the model's suitability for coupled ocean-ice and climate studies. Using the terrain-following-coordinate ocean model ROMS (Regional Ocean Modelling System) coupled to the sea ice model CICE (Community Ice CodE) on a circumpolar Antarctic domain, we compare the performance of three different tracer advection schemes, as well as two levels of parameterised diffusion and the addition of flux limiters to prevent numerical oscillations. The upwind third-order advection scheme performs better than the centered fourth-order and Akima fourth-order advection schemes, with far fewer incidents of spurious sea ice formation. The latter two schemes are less problematic with higher parameterised diffusion, although some supercooling artifacts persist. Spurious supercooling was eliminated by adding flux limiters to the upwind third-order scheme. We present this comparison as evidence of the problematic nature of oscillatory advection schemes in sea ice formation regions, and urge other ocean/sea-ice modellers to exercise caution when using such schemes. Article in Journal/Newspaper Antarc* Antarctic Sea ice Southern Ocean UNSW Sydney (The University of New South Wales): UNSWorks Ocean Modelling 116 108 117 |
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Open Polar |
collection |
UNSW Sydney (The University of New South Wales): UNSWorks |
op_collection_id |
ftunswworks |
language |
unknown |
topic |
14 Life Below Water anzsrc-for: 0405 Oceanography anzsrc-for: 0911 Maritime Engineering |
spellingShingle |
14 Life Below Water anzsrc-for: 0405 Oceanography anzsrc-for: 0911 Maritime Engineering Naughten, KA Galton-Fenzi, BK Meissner, KJ England, MH Brassington, GB Colberg, F Hattermann, T Debernard, JB Spurious sea ice formation caused by oscillatory ocean tracer advection schemes |
topic_facet |
14 Life Below Water anzsrc-for: 0405 Oceanography anzsrc-for: 0911 Maritime Engineering |
description |
Tracer advection schemes used by ocean models are susceptible to artificial oscillations: a form of numerical error whereby the advected field alternates between overshooting and undershooting the exact solution, producing false extrema. Here we show that these oscillations have undesirable interactions with a coupled sea ice model. When oscillations cause the near-surface ocean temperature to fall below the freezing point, sea ice forms for no reason other than numerical error. This spurious sea ice formation has significant and wide-ranging impacts on Southern Ocean simulations, including the disappearance of coastal polynyas, stratification of the water column, erosion of Winter Water, and upwelling of warm Circumpolar Deep Water. This significantly limits the model's suitability for coupled ocean-ice and climate studies. Using the terrain-following-coordinate ocean model ROMS (Regional Ocean Modelling System) coupled to the sea ice model CICE (Community Ice CodE) on a circumpolar Antarctic domain, we compare the performance of three different tracer advection schemes, as well as two levels of parameterised diffusion and the addition of flux limiters to prevent numerical oscillations. The upwind third-order advection scheme performs better than the centered fourth-order and Akima fourth-order advection schemes, with far fewer incidents of spurious sea ice formation. The latter two schemes are less problematic with higher parameterised diffusion, although some supercooling artifacts persist. Spurious supercooling was eliminated by adding flux limiters to the upwind third-order scheme. We present this comparison as evidence of the problematic nature of oscillatory advection schemes in sea ice formation regions, and urge other ocean/sea-ice modellers to exercise caution when using such schemes. |
format |
Article in Journal/Newspaper |
author |
Naughten, KA Galton-Fenzi, BK Meissner, KJ England, MH Brassington, GB Colberg, F Hattermann, T Debernard, JB |
author_facet |
Naughten, KA Galton-Fenzi, BK Meissner, KJ England, MH Brassington, GB Colberg, F Hattermann, T Debernard, JB |
author_sort |
Naughten, KA |
title |
Spurious sea ice formation caused by oscillatory ocean tracer advection schemes |
title_short |
Spurious sea ice formation caused by oscillatory ocean tracer advection schemes |
title_full |
Spurious sea ice formation caused by oscillatory ocean tracer advection schemes |
title_fullStr |
Spurious sea ice formation caused by oscillatory ocean tracer advection schemes |
title_full_unstemmed |
Spurious sea ice formation caused by oscillatory ocean tracer advection schemes |
title_sort |
spurious sea ice formation caused by oscillatory ocean tracer advection schemes |
publisher |
Elsevier |
publishDate |
2017 |
url |
http://hdl.handle.net/1959.4/unsworks_58898 https://unsworks.unsw.edu.au/bitstreams/50a8f21b-3870-45fd-9855-066b106c39e3/download https://doi.org/10.1016/j.ocemod.2017.06.010 |
genre |
Antarc* Antarctic Sea ice Southern Ocean |
genre_facet |
Antarc* Antarctic Sea ice Southern Ocean |
op_source |
urn:ISSN:1463-5003 urn:ISSN:1463-5011 Ocean Modelling, 116, 108-117 |
op_relation |
http://hdl.handle.net/1959.4/unsworks_58898 https://unsworks.unsw.edu.au/bitstreams/50a8f21b-3870-45fd-9855-066b106c39e3/download https://doi.org/10.1016/j.ocemod.2017.06.010 |
op_rights |
open access https://purl.org/coar/access_right/c_abf2 CC-BY-NC-ND https://creativecommons.org/licenses/by-nc-nd/4.0/ free_to_read |
op_doi |
https://doi.org/10.1016/j.ocemod.2017.06.010 |
container_title |
Ocean Modelling |
container_volume |
116 |
container_start_page |
108 |
op_container_end_page |
117 |
_version_ |
1799477086475255808 |