Statistical analysis of global surface temperature and sea level using cointegration methods
Global sea levels are rising which is widely understood as a consequence of thermal expansion and melting of glaciers and land-based ice caps. Due to the lack of representation of ice-sheet dynamics in present-day physically-based climate models being unable to simulate observed sea level trends, se...
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ftcopenhagenunip:oai:pure.atira.dk:publications/880490d1-bca1-44b4-ac21-5bffd4edbb2e 2023-12-03T10:24:26+01:00 Statistical analysis of global surface temperature and sea level using cointegration methods Schmidt, Torben Johansen, Søren Thejll, Peter 2012 https://curis.ku.dk/portal/da/publications/statistical-analysis-of-global-surface-temperature-and-sea-level-using-cointegration-methods(880490d1-bca1-44b4-ac21-5bffd4edbb2e).html https://doi.org/10.1175/JCLI-D-11-00598.1 eng eng info:eu-repo/semantics/restrictedAccess Schmidt , T , Johansen , S & Thejll , P 2012 , ' Statistical analysis of global surface temperature and sea level using cointegration methods ' , Journal of Climate , vol. 25 , no. 22 , pp. 7822-7833 . https://doi.org/10.1175/JCLI-D-11-00598.1 /dk/atira/pure/core/keywords/FacultyOfSocialSciences Faculty of Social Sciences climate analysis cointegration temperature sea level article 2012 ftcopenhagenunip https://doi.org/10.1175/JCLI-D-11-00598.1 2023-11-08T23:59:10Z Global sea levels are rising which is widely understood as a consequence of thermal expansion and melting of glaciers and land-based ice caps. Due to the lack of representation of ice-sheet dynamics in present-day physically-based climate models being unable to simulate observed sea level trends, semi-empirical models have been applied as an alternative for projecting of future sea levels. There is in this, however, potential pitfalls due to the trending nature of the time series. We apply a statistical method called cointegration analysis to observed global sea level and land-ocean surface air temperature, capable of handling such peculiarities. We find a relationship between sea level and temperature and find that temperature causally depends on the sea level, which can be understood as a consequence of the large heat capacity of the ocean. We further find that the warming episode in the 1940s is exceptional in the sense that sea level and warming deviates from the expected relationship. This suggests that this warming episode is mainly due to internal dynamics of the ocean rather than external radiative forcing. On the other hand, the present warming follows the expected relationship, suggesting that it is mainly due to radiative forcing. In a second step, we use the total radiative forcing as an explanatory variable, but unexpectedly find that the sea level does not depend on the forcing. We hypothesize that this is due to a long adjustment time scale of the ocean and show that the number of years of data needed to build statistical models that have the relationship expected from physics exceeds what is currently available by a factor of almost ten. Article in Journal/Newspaper Ice Sheet University of Copenhagen: Research Journal of Climate 25 22 7822 7833 |
institution |
Open Polar |
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University of Copenhagen: Research |
op_collection_id |
ftcopenhagenunip |
language |
English |
topic |
/dk/atira/pure/core/keywords/FacultyOfSocialSciences Faculty of Social Sciences climate analysis cointegration temperature sea level |
spellingShingle |
/dk/atira/pure/core/keywords/FacultyOfSocialSciences Faculty of Social Sciences climate analysis cointegration temperature sea level Schmidt, Torben Johansen, Søren Thejll, Peter Statistical analysis of global surface temperature and sea level using cointegration methods |
topic_facet |
/dk/atira/pure/core/keywords/FacultyOfSocialSciences Faculty of Social Sciences climate analysis cointegration temperature sea level |
description |
Global sea levels are rising which is widely understood as a consequence of thermal expansion and melting of glaciers and land-based ice caps. Due to the lack of representation of ice-sheet dynamics in present-day physically-based climate models being unable to simulate observed sea level trends, semi-empirical models have been applied as an alternative for projecting of future sea levels. There is in this, however, potential pitfalls due to the trending nature of the time series. We apply a statistical method called cointegration analysis to observed global sea level and land-ocean surface air temperature, capable of handling such peculiarities. We find a relationship between sea level and temperature and find that temperature causally depends on the sea level, which can be understood as a consequence of the large heat capacity of the ocean. We further find that the warming episode in the 1940s is exceptional in the sense that sea level and warming deviates from the expected relationship. This suggests that this warming episode is mainly due to internal dynamics of the ocean rather than external radiative forcing. On the other hand, the present warming follows the expected relationship, suggesting that it is mainly due to radiative forcing. In a second step, we use the total radiative forcing as an explanatory variable, but unexpectedly find that the sea level does not depend on the forcing. We hypothesize that this is due to a long adjustment time scale of the ocean and show that the number of years of data needed to build statistical models that have the relationship expected from physics exceeds what is currently available by a factor of almost ten. |
format |
Article in Journal/Newspaper |
author |
Schmidt, Torben Johansen, Søren Thejll, Peter |
author_facet |
Schmidt, Torben Johansen, Søren Thejll, Peter |
author_sort |
Schmidt, Torben |
title |
Statistical analysis of global surface temperature and sea level using cointegration methods |
title_short |
Statistical analysis of global surface temperature and sea level using cointegration methods |
title_full |
Statistical analysis of global surface temperature and sea level using cointegration methods |
title_fullStr |
Statistical analysis of global surface temperature and sea level using cointegration methods |
title_full_unstemmed |
Statistical analysis of global surface temperature and sea level using cointegration methods |
title_sort |
statistical analysis of global surface temperature and sea level using cointegration methods |
publishDate |
2012 |
url |
https://curis.ku.dk/portal/da/publications/statistical-analysis-of-global-surface-temperature-and-sea-level-using-cointegration-methods(880490d1-bca1-44b4-ac21-5bffd4edbb2e).html https://doi.org/10.1175/JCLI-D-11-00598.1 |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_source |
Schmidt , T , Johansen , S & Thejll , P 2012 , ' Statistical analysis of global surface temperature and sea level using cointegration methods ' , Journal of Climate , vol. 25 , no. 22 , pp. 7822-7833 . https://doi.org/10.1175/JCLI-D-11-00598.1 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1175/JCLI-D-11-00598.1 |
container_title |
Journal of Climate |
container_volume |
25 |
container_issue |
22 |
container_start_page |
7822 |
op_container_end_page |
7833 |
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1784272858544865280 |