An evaluation of the LLC4320 global-ocean simulation based on the submesoscale structure of modeled sea surface temperature fields
We have assembled 2 851 702 nearly cloud-free cutout images (sized 144 km × 144 km) of sea surface temperature (SST) data from the entire 2012–2020 Level-2 Visible Infrared Imaging Radiometer Suite (VIIRS) dataset to perform a quantitative comparison to the ocean model output from the MIT General Ci...
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Copernicus Publications
2023
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ftdoajarticles:oai:doaj.org/article:fec8591a8f9449c99cfe459e5898bc01 2024-01-07T09:39:27+01:00 An evaluation of the LLC4320 global-ocean simulation based on the submesoscale structure of modeled sea surface temperature fields K. Gallmeier J. X. Prochaska P. Cornillon D. Menemenlis M. Kelm 2023-12-01T00:00:00Z https://doi.org/10.5194/gmd-16-7143-2023 https://doaj.org/article/fec8591a8f9449c99cfe459e5898bc01 EN eng Copernicus Publications https://gmd.copernicus.org/articles/16/7143/2023/gmd-16-7143-2023.pdf https://doaj.org/toc/1991-959X https://doaj.org/toc/1991-9603 doi:10.5194/gmd-16-7143-2023 1991-959X 1991-9603 https://doaj.org/article/fec8591a8f9449c99cfe459e5898bc01 Geoscientific Model Development, Vol 16, Pp 7143-7170 (2023) Geology QE1-996.5 article 2023 ftdoajarticles https://doi.org/10.5194/gmd-16-7143-2023 2023-12-10T01:37:38Z We have assembled 2 851 702 nearly cloud-free cutout images (sized 144 km × 144 km) of sea surface temperature (SST) data from the entire 2012–2020 Level-2 Visible Infrared Imaging Radiometer Suite (VIIRS) dataset to perform a quantitative comparison to the ocean model output from the MIT General Circulation Model (MITgcm). Specifically, we evaluate outputs from the LLC4320 (LLC, latitude–longitude–polar cap) 1 48 ∘ <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="17pt" height="16pt" class="svg-formula" dspmath="mathimg" md5hash="6cd7ff63ab90fa70446e96a3f73d8b37"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="gmd-16-7143-2023-ie00001.svg" width="17pt" height="16pt" src="gmd-16-7143-2023-ie00001.png"/></svg:svg> global-ocean simulation for a 1-year period starting on 17 November 2011 but otherwise matched in geography and the day of the year to the VIIRS observations. In lieu of simple (e.g., mean, standard deviation) or complex (e.g., power spectrum) statistics, we analyze the cutouts of SST anomalies with an unsupervised probabilistic autoencoder (PAE) trained to learn the distribution of structures in SST anomaly (SSTa) on ∼ 10– 80 km scales (i.e., submesoscale to mesoscale). A principal finding is that the LLC4320 simulation reproduces, over a large fraction of the ocean, the observed distribution of SSTa patterns well, both globally and regionally. Globally, the medians of the structure distributions match to within 2 σ for 65 % of the ocean, despite a modest, latitude-dependent offset. Regionally, the model outputs reproduce mesoscale variations in SSTa patterns revealed by the PAE in the VIIRS data, including subtle features imprinted by variations in bathymetry. We also identify significant differences in the distribution of SSTa patterns in several regions: (1) in an equatorial band equatorward of 15 ∘ (2) in the Antarctic Circumpolar Current (ACC), especially in the eastern half of the Indian Ocean; and (3) in the vicinity of the point at which western ... Article in Journal/Newspaper Antarc* Antarctic Directory of Open Access Journals: DOAJ Articles Antarctic Indian The Antarctic Geoscientific Model Development 16 23 7143 7170 |
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Directory of Open Access Journals: DOAJ Articles |
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ftdoajarticles |
language |
English |
topic |
Geology QE1-996.5 |
spellingShingle |
Geology QE1-996.5 K. Gallmeier J. X. Prochaska P. Cornillon D. Menemenlis M. Kelm An evaluation of the LLC4320 global-ocean simulation based on the submesoscale structure of modeled sea surface temperature fields |
topic_facet |
Geology QE1-996.5 |
description |
We have assembled 2 851 702 nearly cloud-free cutout images (sized 144 km × 144 km) of sea surface temperature (SST) data from the entire 2012–2020 Level-2 Visible Infrared Imaging Radiometer Suite (VIIRS) dataset to perform a quantitative comparison to the ocean model output from the MIT General Circulation Model (MITgcm). Specifically, we evaluate outputs from the LLC4320 (LLC, latitude–longitude–polar cap) 1 48 ∘ <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="17pt" height="16pt" class="svg-formula" dspmath="mathimg" md5hash="6cd7ff63ab90fa70446e96a3f73d8b37"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="gmd-16-7143-2023-ie00001.svg" width="17pt" height="16pt" src="gmd-16-7143-2023-ie00001.png"/></svg:svg> global-ocean simulation for a 1-year period starting on 17 November 2011 but otherwise matched in geography and the day of the year to the VIIRS observations. In lieu of simple (e.g., mean, standard deviation) or complex (e.g., power spectrum) statistics, we analyze the cutouts of SST anomalies with an unsupervised probabilistic autoencoder (PAE) trained to learn the distribution of structures in SST anomaly (SSTa) on ∼ 10– 80 km scales (i.e., submesoscale to mesoscale). A principal finding is that the LLC4320 simulation reproduces, over a large fraction of the ocean, the observed distribution of SSTa patterns well, both globally and regionally. Globally, the medians of the structure distributions match to within 2 σ for 65 % of the ocean, despite a modest, latitude-dependent offset. Regionally, the model outputs reproduce mesoscale variations in SSTa patterns revealed by the PAE in the VIIRS data, including subtle features imprinted by variations in bathymetry. We also identify significant differences in the distribution of SSTa patterns in several regions: (1) in an equatorial band equatorward of 15 ∘ (2) in the Antarctic Circumpolar Current (ACC), especially in the eastern half of the Indian Ocean; and (3) in the vicinity of the point at which western ... |
format |
Article in Journal/Newspaper |
author |
K. Gallmeier J. X. Prochaska P. Cornillon D. Menemenlis M. Kelm |
author_facet |
K. Gallmeier J. X. Prochaska P. Cornillon D. Menemenlis M. Kelm |
author_sort |
K. Gallmeier |
title |
An evaluation of the LLC4320 global-ocean simulation based on the submesoscale structure of modeled sea surface temperature fields |
title_short |
An evaluation of the LLC4320 global-ocean simulation based on the submesoscale structure of modeled sea surface temperature fields |
title_full |
An evaluation of the LLC4320 global-ocean simulation based on the submesoscale structure of modeled sea surface temperature fields |
title_fullStr |
An evaluation of the LLC4320 global-ocean simulation based on the submesoscale structure of modeled sea surface temperature fields |
title_full_unstemmed |
An evaluation of the LLC4320 global-ocean simulation based on the submesoscale structure of modeled sea surface temperature fields |
title_sort |
evaluation of the llc4320 global-ocean simulation based on the submesoscale structure of modeled sea surface temperature fields |
publisher |
Copernicus Publications |
publishDate |
2023 |
url |
https://doi.org/10.5194/gmd-16-7143-2023 https://doaj.org/article/fec8591a8f9449c99cfe459e5898bc01 |
geographic |
Antarctic Indian The Antarctic |
geographic_facet |
Antarctic Indian The Antarctic |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
Geoscientific Model Development, Vol 16, Pp 7143-7170 (2023) |
op_relation |
https://gmd.copernicus.org/articles/16/7143/2023/gmd-16-7143-2023.pdf https://doaj.org/toc/1991-959X https://doaj.org/toc/1991-9603 doi:10.5194/gmd-16-7143-2023 1991-959X 1991-9603 https://doaj.org/article/fec8591a8f9449c99cfe459e5898bc01 |
op_doi |
https://doi.org/10.5194/gmd-16-7143-2023 |
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Geoscientific Model Development |
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16 |
container_issue |
23 |
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7143 |
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7170 |
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1787429639928414208 |