author_facet Gregory, William
Stroeve, Julienne
Tsamados, Michel
Gregory, William
Stroeve, Julienne
Tsamados, Michel
author Gregory, William
Stroeve, Julienne
Tsamados, Michel
spellingShingle Gregory, William
Stroeve, Julienne
Tsamados, Michel
The Cryosphere
Network connectivity between the winter Arctic Oscillation and summer sea ice in CMIP6 models and observations
Earth-Surface Processes
Water Science and Technology
author_sort gregory, william
spelling Gregory, William Stroeve, Julienne Tsamados, Michel 1994-0424 Copernicus GmbH Earth-Surface Processes Water Science and Technology http://dx.doi.org/10.5194/tc-16-1653-2022 <jats:p>Abstract. The indirect effect of winter Arctic Oscillation (AO) events on the following summer Arctic sea ice extent suggests an inherent winter-to-summer mechanism for sea ice predictability. On the other hand, operational regional summer sea ice forecasts in a large number of coupled climate models show a considerable drop in predictive skill for forecasts initialised prior to the date of melt onset in spring, suggesting that some drivers of sea ice variability on longer timescales may not be well represented in these models. To this end, we introduce an unsupervised learning approach based on cluster analysis and complex networks to establish how well the latest generation of coupled climate models participating in phase 6 of the World Climate Research Programme Coupled Model Intercomparison Project (CMIP6) are able to reflect the spatio-temporal patterns of variability in Northern Hemisphere winter sea-level pressure and Arctic summer sea ice concentration over the period 1979–2020, relative to ERA5 atmospheric reanalysis and satellite-derived sea ice observations, respectively. Two specific global metrics are introduced as ways to compare patterns of variability between models and observations/reanalysis: the adjusted Rand index – a method for comparing spatial patterns of variability – and a network distance metric – a method for comparing the degree of connectivity between two geographic regions. We find that CMIP6 models generally reflect the spatial pattern of variability in the AO relatively well, although they overestimate the magnitude of sea-level pressure variability over the north-western Pacific Ocean and underestimate the variability over northern Africa and southern Europe. They also underestimate the importance of regions such as the Beaufort, East Siberian, and Laptev seas in explaining pan-Arctic summer sea ice area variability, which we hypothesise is due to regional biases in sea ice thickness. Finally, observations show that historically, winter AO events (negatively) covary strongly with summer sea ice concentration in the eastern Pacific sector of the Arctic, although now under a thinning ice regime, both the eastern and western Pacific sectors exhibit similar behaviour. CMIP6 models however do not show this transition on average, which may hinder their ability to make skilful seasonal to inter-annual predictions of summer sea ice. </jats:p> Network connectivity between the winter Arctic Oscillation and summer sea ice in CMIP6 models and observations The Cryosphere
doi_str_mv 10.5194/tc-16-1653-2022
facet_avail Online
Free
finc_class_facet Geologie und Paläontologie
Geographie
Technik
format ElectronicArticle
fullrecord blob:ai-49-aHR0cDovL2R4LmRvaS5vcmcvMTAuNTE5NC90Yy0xNi0xNjUzLTIwMjI
id ai-49-aHR0cDovL2R4LmRvaS5vcmcvMTAuNTE5NC90Yy0xNi0xNjUzLTIwMjI
institution DE-D275
DE-Bn3
DE-Brt1
DE-Zwi2
DE-D161
DE-Gla1
DE-Zi4
DE-15
DE-Pl11
DE-Rs1
DE-105
DE-14
DE-Ch1
DE-L229
imprint Copernicus GmbH, 2022
imprint_str_mv Copernicus GmbH, 2022
issn 1994-0424
issn_str_mv 1994-0424
language English
mega_collection Copernicus GmbH (CrossRef)
match_str gregory2022networkconnectivitybetweenthewinterarcticoscillationandsummerseaiceincmip6modelsandobservations
publishDateSort 2022
publisher Copernicus GmbH
recordtype ai
record_format ai
series The Cryosphere
source_id 49
title Network connectivity between the winter Arctic Oscillation and summer sea ice in CMIP6 models and observations
title_unstemmed Network connectivity between the winter Arctic Oscillation and summer sea ice in CMIP6 models and observations
title_full Network connectivity between the winter Arctic Oscillation and summer sea ice in CMIP6 models and observations
title_fullStr Network connectivity between the winter Arctic Oscillation and summer sea ice in CMIP6 models and observations
title_full_unstemmed Network connectivity between the winter Arctic Oscillation and summer sea ice in CMIP6 models and observations
title_short Network connectivity between the winter Arctic Oscillation and summer sea ice in CMIP6 models and observations
title_sort network connectivity between the winter arctic oscillation and summer sea ice in cmip6 models and observations
topic Earth-Surface Processes
Water Science and Technology
url http://dx.doi.org/10.5194/tc-16-1653-2022
publishDate 2022
physical 1653-1673
description <jats:p>Abstract. The indirect effect of winter Arctic Oscillation (AO) events on the following summer Arctic sea ice extent suggests an inherent winter-to-summer mechanism for sea ice predictability. On the other hand, operational regional summer sea ice forecasts in a large number of coupled climate models show a considerable drop in predictive skill for forecasts initialised prior to the date of melt onset in spring, suggesting that some drivers of sea ice variability on longer timescales may not be well represented in these models. To this end, we introduce an unsupervised learning approach based on cluster analysis and complex networks to establish how well the latest generation of coupled climate models participating in phase 6 of the World Climate Research Programme Coupled Model Intercomparison Project (CMIP6) are able to reflect the spatio-temporal patterns of variability in Northern Hemisphere winter sea-level pressure and Arctic summer sea ice concentration over the period 1979–2020, relative to ERA5 atmospheric reanalysis and satellite-derived sea ice observations, respectively. Two specific global metrics are introduced as ways to compare patterns of variability between models and observations/reanalysis: the adjusted Rand index – a method for comparing spatial patterns of variability – and a network distance metric – a method for comparing the degree of connectivity between two geographic regions. We find that CMIP6 models generally reflect the spatial pattern of variability in the AO relatively well, although they overestimate the magnitude of sea-level pressure variability over the north-western Pacific Ocean and underestimate the variability over northern Africa and southern Europe. They also underestimate the importance of regions such as the Beaufort, East Siberian, and Laptev seas in explaining pan-Arctic summer sea ice area variability, which we hypothesise is due to regional biases in sea ice thickness. Finally, observations show that historically, winter AO events (negatively) covary strongly with summer sea ice concentration in the eastern Pacific sector of the Arctic, although now under a thinning ice regime, both the eastern and western Pacific sectors exhibit similar behaviour. CMIP6 models however do not show this transition on average, which may hinder their ability to make skilful seasonal to inter-annual predictions of summer sea ice. </jats:p>
container_issue 5
container_start_page 1653
container_title The Cryosphere
container_volume 16
format_de105 Article, E-Article
format_de14 Article, E-Article
format_de15 Article, E-Article
format_de520 Article, E-Article
format_de540 Article, E-Article
format_dech1 Article, E-Article
format_ded117 Article, E-Article
format_degla1 E-Article
format_del152 Buch
format_del189 Article, E-Article
format_dezi4 Article
format_dezwi2 Article, E-Article
format_finc Article, E-Article
format_nrw Article, E-Article
_version_ 1792347422997872646
geogr_code not assigned
last_indexed 2024-03-01T17:55:00.727Z
geogr_code_person not assigned
openURL url_ver=Z39.88-2004&ctx_ver=Z39.88-2004&ctx_enc=info%3Aofi%2Fenc%3AUTF-8&rfr_id=info%3Asid%2Fvufind.svn.sourceforge.net%3Agenerator&rft.title=Network+connectivity+between+the+winter+Arctic+Oscillation+and+summer+sea+ice+in+CMIP6+models+and+observations&rft.date=2022-05-05&genre=article&issn=1994-0424&volume=16&issue=5&spage=1653&epage=1673&pages=1653-1673&jtitle=The+Cryosphere&atitle=Network+connectivity+between+the+winter+Arctic+Oscillation+and+summer+sea+ice+in+CMIP6+models+and+observations&aulast=Tsamados&aufirst=Michel&rft_id=info%3Adoi%2F10.5194%2Ftc-16-1653-2022&rft.language%5B0%5D=eng
SOLR
_version_ 1792347422997872646
author Gregory, William, Stroeve, Julienne, Tsamados, Michel
author_facet Gregory, William, Stroeve, Julienne, Tsamados, Michel, Gregory, William, Stroeve, Julienne, Tsamados, Michel
author_sort gregory, william
container_issue 5
container_start_page 1653
container_title The Cryosphere
container_volume 16
description <jats:p>Abstract. The indirect effect of winter Arctic Oscillation (AO) events on the following summer Arctic sea ice extent suggests an inherent winter-to-summer mechanism for sea ice predictability. On the other hand, operational regional summer sea ice forecasts in a large number of coupled climate models show a considerable drop in predictive skill for forecasts initialised prior to the date of melt onset in spring, suggesting that some drivers of sea ice variability on longer timescales may not be well represented in these models. To this end, we introduce an unsupervised learning approach based on cluster analysis and complex networks to establish how well the latest generation of coupled climate models participating in phase 6 of the World Climate Research Programme Coupled Model Intercomparison Project (CMIP6) are able to reflect the spatio-temporal patterns of variability in Northern Hemisphere winter sea-level pressure and Arctic summer sea ice concentration over the period 1979–2020, relative to ERA5 atmospheric reanalysis and satellite-derived sea ice observations, respectively. Two specific global metrics are introduced as ways to compare patterns of variability between models and observations/reanalysis: the adjusted Rand index – a method for comparing spatial patterns of variability – and a network distance metric – a method for comparing the degree of connectivity between two geographic regions. We find that CMIP6 models generally reflect the spatial pattern of variability in the AO relatively well, although they overestimate the magnitude of sea-level pressure variability over the north-western Pacific Ocean and underestimate the variability over northern Africa and southern Europe. They also underestimate the importance of regions such as the Beaufort, East Siberian, and Laptev seas in explaining pan-Arctic summer sea ice area variability, which we hypothesise is due to regional biases in sea ice thickness. Finally, observations show that historically, winter AO events (negatively) covary strongly with summer sea ice concentration in the eastern Pacific sector of the Arctic, although now under a thinning ice regime, both the eastern and western Pacific sectors exhibit similar behaviour. CMIP6 models however do not show this transition on average, which may hinder their ability to make skilful seasonal to inter-annual predictions of summer sea ice. </jats:p>
doi_str_mv 10.5194/tc-16-1653-2022
facet_avail Online, Free
finc_class_facet Geologie und Paläontologie, Geographie, Technik
format ElectronicArticle
format_de105 Article, E-Article
format_de14 Article, E-Article
format_de15 Article, E-Article
format_de520 Article, E-Article
format_de540 Article, E-Article
format_dech1 Article, E-Article
format_ded117 Article, E-Article
format_degla1 E-Article
format_del152 Buch
format_del189 Article, E-Article
format_dezi4 Article
format_dezwi2 Article, E-Article
format_finc Article, E-Article
format_nrw Article, E-Article
geogr_code not assigned
geogr_code_person not assigned
id ai-49-aHR0cDovL2R4LmRvaS5vcmcvMTAuNTE5NC90Yy0xNi0xNjUzLTIwMjI
imprint Copernicus GmbH, 2022
imprint_str_mv Copernicus GmbH, 2022
institution DE-D275, DE-Bn3, DE-Brt1, DE-Zwi2, DE-D161, DE-Gla1, DE-Zi4, DE-15, DE-Pl11, DE-Rs1, DE-105, DE-14, DE-Ch1, DE-L229
issn 1994-0424
issn_str_mv 1994-0424
language English
last_indexed 2024-03-01T17:55:00.727Z
match_str gregory2022networkconnectivitybetweenthewinterarcticoscillationandsummerseaiceincmip6modelsandobservations
mega_collection Copernicus GmbH (CrossRef)
physical 1653-1673
publishDate 2022
publishDateSort 2022
publisher Copernicus GmbH
record_format ai
recordtype ai
series The Cryosphere
source_id 49
spelling Gregory, William Stroeve, Julienne Tsamados, Michel 1994-0424 Copernicus GmbH Earth-Surface Processes Water Science and Technology http://dx.doi.org/10.5194/tc-16-1653-2022 <jats:p>Abstract. The indirect effect of winter Arctic Oscillation (AO) events on the following summer Arctic sea ice extent suggests an inherent winter-to-summer mechanism for sea ice predictability. On the other hand, operational regional summer sea ice forecasts in a large number of coupled climate models show a considerable drop in predictive skill for forecasts initialised prior to the date of melt onset in spring, suggesting that some drivers of sea ice variability on longer timescales may not be well represented in these models. To this end, we introduce an unsupervised learning approach based on cluster analysis and complex networks to establish how well the latest generation of coupled climate models participating in phase 6 of the World Climate Research Programme Coupled Model Intercomparison Project (CMIP6) are able to reflect the spatio-temporal patterns of variability in Northern Hemisphere winter sea-level pressure and Arctic summer sea ice concentration over the period 1979–2020, relative to ERA5 atmospheric reanalysis and satellite-derived sea ice observations, respectively. Two specific global metrics are introduced as ways to compare patterns of variability between models and observations/reanalysis: the adjusted Rand index – a method for comparing spatial patterns of variability – and a network distance metric – a method for comparing the degree of connectivity between two geographic regions. We find that CMIP6 models generally reflect the spatial pattern of variability in the AO relatively well, although they overestimate the magnitude of sea-level pressure variability over the north-western Pacific Ocean and underestimate the variability over northern Africa and southern Europe. They also underestimate the importance of regions such as the Beaufort, East Siberian, and Laptev seas in explaining pan-Arctic summer sea ice area variability, which we hypothesise is due to regional biases in sea ice thickness. Finally, observations show that historically, winter AO events (negatively) covary strongly with summer sea ice concentration in the eastern Pacific sector of the Arctic, although now under a thinning ice regime, both the eastern and western Pacific sectors exhibit similar behaviour. CMIP6 models however do not show this transition on average, which may hinder their ability to make skilful seasonal to inter-annual predictions of summer sea ice. </jats:p> Network connectivity between the winter Arctic Oscillation and summer sea ice in CMIP6 models and observations The Cryosphere
spellingShingle Gregory, William, Stroeve, Julienne, Tsamados, Michel, The Cryosphere, Network connectivity between the winter Arctic Oscillation and summer sea ice in CMIP6 models and observations, Earth-Surface Processes, Water Science and Technology
title Network connectivity between the winter Arctic Oscillation and summer sea ice in CMIP6 models and observations
title_full Network connectivity between the winter Arctic Oscillation and summer sea ice in CMIP6 models and observations
title_fullStr Network connectivity between the winter Arctic Oscillation and summer sea ice in CMIP6 models and observations
title_full_unstemmed Network connectivity between the winter Arctic Oscillation and summer sea ice in CMIP6 models and observations
title_short Network connectivity between the winter Arctic Oscillation and summer sea ice in CMIP6 models and observations
title_sort network connectivity between the winter arctic oscillation and summer sea ice in cmip6 models and observations
title_unstemmed Network connectivity between the winter Arctic Oscillation and summer sea ice in CMIP6 models and observations
topic Earth-Surface Processes, Water Science and Technology
url http://dx.doi.org/10.5194/tc-16-1653-2022