Complementing thermosteric sea level rise estimates
Thermal expansion of seawater has been one of the most important contributors to global sea level rise (SLR) over the past 100 years. Yet, observational estimates of this volumetric response of the world's oceans to temperature changes are sparse and mostly limited to the ocean's upper 700...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2015-09-01
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| Series: | Geoscientific Model Development |
| Online Access: | http://www.geosci-model-dev.net/8/2723/2015/gmd-8-2723-2015.pdf |
| _version_ | 1819035551092703232 |
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| author | K. Lorbacher A. Nauels M. Meinshausen |
| author_facet | K. Lorbacher A. Nauels M. Meinshausen |
| author_sort | K. Lorbacher |
| collection | DOAJ |
| description | Thermal expansion of seawater has been one of the most important contributors to
global sea level rise (SLR) over the past 100 years. Yet, observational
estimates of this volumetric response of the world's oceans to temperature
changes are sparse and mostly limited to the ocean's upper 700 m.
Furthermore, only a part of the available climate model data is sufficiently
diagnosed to complete our quantitative understanding of thermosteric SLR
(thSLR). Here, we extend the available set of thSLR diagnostics from the
Coupled Model Intercomparison Project Phase 5 (CMIP5), analyze those model
results in order to complement upper-ocean observations and enable the
development of surrogate techniques to project thSLR using vertical
temperature profile and ocean heat uptake time series. Specifically, based on
CMIP5 temperature and salinity data, we provide a compilation of thermal
expansion time series that comprise 30 % more simulations than currently
published within CMIP5. We find that 21st century thSLR estimates derived
solely based on observational estimates from the upper 700 m (2000 m) would
have to be multiplied by a factor of 1.39 (1.17) with 90 % uncertainty
ranges of 1.24 to 1.58 (1.05 to 1.31) in order to account for thSLR
contributions from deeper levels. Half (50 %) of the multi-model total
expansion originates from depths below 490 ± 90 m, with the range
indicating scenario-to-scenario variations. To support the development of
surrogate methods to project thermal expansion, we calibrate two simplified
parameterizations against CMIP5 estimates of thSLR: one parameterization is
suitable for scenarios where hemispheric ocean temperature profiles are
available, the other, where only the total ocean heat uptake is known
(goodness of fit: ±5 and ±9 %, respectively). |
| first_indexed | 2024-12-21T07:51:25Z |
| format | Article |
| id | doaj.art-807af651a2bc4932bc3de015c77a1062 |
| institution | Directory Open Access Journal |
| issn | 1991-959X 1991-9603 |
| language | English |
| last_indexed | 2024-12-21T07:51:25Z |
| publishDate | 2015-09-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Geoscientific Model Development |
| spelling | doaj.art-807af651a2bc4932bc3de015c77a10622022-12-21T19:11:05ZengCopernicus PublicationsGeoscientific Model Development1991-959X1991-96032015-09-01892723273410.5194/gmd-8-2723-2015Complementing thermosteric sea level rise estimatesK. Lorbacher0A. Nauels1M. Meinshausen2Australian-German College of Climate & Energy Transitions, School of Earth Sciences, The University of Melbourne, Parkville 3010, Victoria, AustraliaAustralian-German College of Climate & Energy Transitions, School of Earth Sciences, The University of Melbourne, Parkville 3010, Victoria, AustraliaAustralian-German College of Climate & Energy Transitions, School of Earth Sciences, The University of Melbourne, Parkville 3010, Victoria, AustraliaThermal expansion of seawater has been one of the most important contributors to global sea level rise (SLR) over the past 100 years. Yet, observational estimates of this volumetric response of the world's oceans to temperature changes are sparse and mostly limited to the ocean's upper 700 m. Furthermore, only a part of the available climate model data is sufficiently diagnosed to complete our quantitative understanding of thermosteric SLR (thSLR). Here, we extend the available set of thSLR diagnostics from the Coupled Model Intercomparison Project Phase 5 (CMIP5), analyze those model results in order to complement upper-ocean observations and enable the development of surrogate techniques to project thSLR using vertical temperature profile and ocean heat uptake time series. Specifically, based on CMIP5 temperature and salinity data, we provide a compilation of thermal expansion time series that comprise 30 % more simulations than currently published within CMIP5. We find that 21st century thSLR estimates derived solely based on observational estimates from the upper 700 m (2000 m) would have to be multiplied by a factor of 1.39 (1.17) with 90 % uncertainty ranges of 1.24 to 1.58 (1.05 to 1.31) in order to account for thSLR contributions from deeper levels. Half (50 %) of the multi-model total expansion originates from depths below 490 ± 90 m, with the range indicating scenario-to-scenario variations. To support the development of surrogate methods to project thermal expansion, we calibrate two simplified parameterizations against CMIP5 estimates of thSLR: one parameterization is suitable for scenarios where hemispheric ocean temperature profiles are available, the other, where only the total ocean heat uptake is known (goodness of fit: ±5 and ±9 %, respectively).http://www.geosci-model-dev.net/8/2723/2015/gmd-8-2723-2015.pdf |
| spellingShingle | K. Lorbacher A. Nauels M. Meinshausen Complementing thermosteric sea level rise estimates Geoscientific Model Development |
| title | Complementing thermosteric sea level rise estimates |
| title_full | Complementing thermosteric sea level rise estimates |
| title_fullStr | Complementing thermosteric sea level rise estimates |
| title_full_unstemmed | Complementing thermosteric sea level rise estimates |
| title_short | Complementing thermosteric sea level rise estimates |
| title_sort | complementing thermosteric sea level rise estimates |
| url | http://www.geosci-model-dev.net/8/2723/2015/gmd-8-2723-2015.pdf |
| work_keys_str_mv | AT klorbacher complementingthermostericsealevelriseestimates AT anauels complementingthermostericsealevelriseestimates AT mmeinshausen complementingthermostericsealevelriseestimates |