scholarly journals Contribution of Land Water Storage Change to Regional Sea-Level Rise Over the Twenty-First Century

2021 ◽  
Vol 9 ◽  
Author(s):  
Sitar Karabil ◽  
Edwin H. Sutanudjaja ◽  
Erwin Lambert ◽  
Marc F. P. Bierkens ◽  
Roderik S. W. Van de Wal
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Climate Models ◽  
Sea Level Change ◽  
First Century ◽  
Level Change ◽  
Regional Sea Level ◽  
Twenty First Century ◽  
Land Water ◽  
Global Mean

Change in Land Water Storage (LWS) is one of the main components driving sea-level rise over the twenty-first century. LWS alteration results from both human activities and climate change. Up to now, all components to sea-level change are usually quantified upon a certain climate change scenario except land water changes. Here, we propose to improve this by analyzing the contribution of LWS to regional sea-level change by considering five Coupled Model Intercomparison Project Phase 5 (CMIP5) climate models forced by three different Representative Concentration Pathway (RCP) greenhouse gas emission scenarios. For this analysis, we used LWS output of the global hydrological and water resources model, PCR-GLOBWB 2, in order to project regional sea-level patterns. Projections of ensemble means indicate a range of LWS-driven sea-level rise with larger differences in projections among climate models than between scenarios. Our results suggest that LWS change will contribute around 10% to the projected global mean sea-level rise by the end of twenty-first century. Contribution of LWS to regional sea-level rise is projected to be considerably larger than the global mean over several regions, up to 60% higher than global average of LWS-driven sea-level rise, including the Pacific islands, the south coast of Africa and the west coast of Australia.

scholarly journals Reconciling global mean and regional sea level change in projections and observations

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jinping Wang ◽  
John A. Church ◽  
Xuebin Zhang ◽  
Xianyao Chen
Keyword(s):  
Sea Level ◽  
Climate Models ◽  
Tide Gauge ◽  
Sea Level Change ◽  
Global Network ◽  
Weighted Mean ◽  
Level Change ◽  
Regional Sea Level ◽  
Global Mean ◽  
Regional Sea Level Change

AbstractThe ability of climate models to simulate 20th century global mean sea level (GMSL) and regional sea-level change has been demonstrated. However, the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5) and Special Report on the Ocean and Cryosphere in a Changing Climate (SROCC) sea-level projections have not been rigorously evaluated with observed GMSL and coastal sea level from a global network of tide gauges as the short overlapping period (2007–2018) and natural variability make the detection of trends and accelerations challenging. Here, we critically evaluate these projections with satellite and tide-gauge observations. The observed trends from GMSL and the regional weighted mean at tide-gauge stations confirm the projections under three Representative Concentration Pathway (RCP) scenarios within 90% confidence level during 2007–2018. The central values of the observed GMSL (1993–2018) and regional weighted mean (1970–2018) accelerations are larger than projections for RCP2.6 and lie between (or even above) those for RCP4.5 and RCP8.5 over 2007–2032, but are not yet statistically different from any scenario. While the confirmation of the projection trends gives us confidence in current understanding of near future sea-level change, it leaves open questions concerning late 21st century non-linear accelerations from ice-sheet contributions.

The Sea Level Response to External Forcings in Historical Simulations of CMIP5 Climate Models*

2015 ◽  
Vol 28 (21) ◽  
pp. 8521-8539 ◽  
Author(s):  
Aimée B. A. Slangen ◽  
John A. Church ◽  
Xuebin Zhang ◽  
Didier P. Monselesan
Keyword(s):  
Climate Variability ◽  
Sea Level ◽  
Regional Scale ◽  
Volcanic Eruptions ◽  
Sea Level Change ◽  
Internal Climate Variability ◽  
Level Change ◽  
External Forcings ◽  
Regional Sea Level ◽  
Global Mean

Abstract Changes in Earth’s climate are influenced by internal climate variability and external forcings, such as changes in solar radiation, volcanic eruptions, anthropogenic greenhouse gases (GHG), and aerosols. Although the response of surface temperature to external forcings has been studied extensively, this has not been done for sea level. Here, a range of climate model experiments for the twentieth century is used to study the response of global and regional sea level change to external climate forcings. Both the global mean thermosteric sea level and the regional dynamic sea level patterns show clear responses to anthropogenic forcings that are significantly different from internal climate variability and larger than the difference between models driven by the same external forcing. The regional sea level patterns are directly related to changes in surface winds in response to the external forcings. The spread between different realizations of the same model experiment is consistent with internal climate variability derived from preindustrial control simulations. The spread between the different models is larger than the internal variability, mainly in regions with large sea level responses. Although the sea level responses to GHG and anthropogenic aerosol forcing oppose each other in the global mean, there are differences on a regional scale, offering opportunities for distinguishing between these two forcings in observed sea level change.

scholarly journals The land-ice contribution to 21st century dynamic sea-level rise

2014 ◽  
Vol 11 (1) ◽  
pp. 123-169 ◽  
Author(s):  
T. Howard ◽  
J. Ridley ◽  
A. K. Pardaens ◽  
R. T. W. L. Hurkmans ◽  
A. J. Payne ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
21St Century ◽  
Sea Level Change ◽  
Sea Level Changes ◽  
Mean Sea Level ◽  
Ice Melt ◽  
Level Change ◽  
Global Mean ◽  
Dynamic Sea Level

Abstract. Climate change has the potential to locally influence mean sea level through a number of processes including (but not limited to) thermal expansion of the oceans and enhanced land ice melt. These lead to departures from the global mean sea level change, due to spatial variations in the change of water density and transport, which are termed dynamic sea level changes. In this study we present regional patterns of sea-level change projected by a global coupled atmosphere–ocean climate model forced by projected ice-melt fluxes from three sources: the Antarctic ice sheet, the Greenland ice sheet and small glaciers and ice caps. The largest ice melt flux we consider is equivalent to almost 0.7 m of global sea level rise over the 21st century. Since the ice melt is not constant, the evolution of the dynamic sea level changes is analysed. We find that the dynamic sea level change associated with the ice melt is small, with the largest changes, occurring in the North Atlantic, contributing of order 3 cm above the global mean rise. Furthermore, the dynamic sea level change associated with the ice melt is similar regardless of whether the simulated ice fluxes are applied to a simulation with fixed or changing atmospheric CO2.

scholarly journals Towards regional projections of twenty-first century sea-level change based on IPCC SRES scenarios

2011 ◽  
Vol 38 (5-6) ◽  
pp. 1191-1209 ◽  
Author(s):  
A. B. A. Slangen ◽  
C. A. Katsman ◽  
R. S. W. van de Wal ◽  
L. L. A. Vermeersen ◽  
R. E. M. Riva
Keyword(s):  
Sea Level ◽  
Sea Level Change ◽  
First Century ◽  
Level Change ◽  
Twenty First Century ◽  
Sres Scenarios ◽  
Ipcc Sres ◽  
Ipcc Sres Scenarios

scholarly journals Explaining the Spread in Global Mean Thermosteric Sea Level Rise in CMIP5 Climate Models*

2015 ◽  
Vol 28 (24) ◽  
pp. 9918-9940 ◽  
Author(s):  
Angélique Melet ◽  
Benoit Meyssignac
Keyword(s):  
Twentieth Century ◽  
Sea Level ◽  
Radiative Forcing ◽  
Climate Models ◽  
First Century ◽  
Model Ensemble ◽  
Ocean Heat Uptake ◽  
Feedback Parameter ◽  
Twenty First Century ◽  
Global Mean

Abstract The ocean stores more than 90% of the energy excess associated with anthropogenic climate change. The resulting ocean warming and thermal expansion are leading contributors to global mean sea level (GMSL) rise. Confidence in projections of GMSL rise therefore depends on the ability of climate models to reproduce global mean thermosteric sea level (GMTSL) rise over the twentieth century. This study first compares the GMTSL of the climate models from phase 5 of the Coupled Model Intercomparison Project (CMIP5) to observations over 1961–2005. Although the model ensemble mean is within the uncertainty of observations, the model ensemble exhibits a large spread. The authors then aim to explain the spread in CMIP5 climate model GMTSL over the twentieth and twenty-first centuries. It is shown that the climate models’ GMTSL rise depends linearly on the time-integrated radiative forcing F (under continuously increasing radiative forcing). The constant of proportionality μ expresses the transient thermosteric sea level response of the climate system, and it depends on the fraction of excess heat stored in the ocean, the expansion efficiency of heat, the climate feedback parameter, and the ocean heat uptake efficiency. The across-model spread in μ explains most (>70%) of the across-model spread in GMTSL rise over the twentieth and twenty-first centuries, while the across-model spread in time-integrated F explains the rest. The time-integrated F explains less variance in the across-model GMTSL rise in twenty-first-century than in twentieth-century simulations, as the spread in F is reduced over the twenty-first century because the anthropogenic aerosol forcing, which is a large source of uncertainty in F, becomes relatively smaller.

Consequences of twenty-first-century policy for multi-millennial climate and sea-level change

2016 ◽  
Vol 6 (4) ◽  
pp. 360-369 ◽  
Author(s):  
Peter U. Clark ◽  
Jeremy D. Shakun ◽  
Shaun A. Marcott ◽  
Alan C. Mix ◽  
Michael Eby ◽  
...  
Keyword(s):  
Sea Level ◽  
Sea Level Change ◽  
First Century ◽  
Level Change ◽  
Twenty First Century ◽  
And Sea Level

A revised sea level budget equation to accurately represent physical processes driving sea level rise

2020 ◽  
Author(s):  
Bramha Dutt Vishwakarma ◽  
Sam Royston ◽  
Ricardo E. M. Riva ◽  
Richard M. Westaway ◽  
Jonathan L. Bamber
Keyword(s):  
Solid Earth ◽  
Sea Level ◽  
Sea Level Change ◽  
Ocean Bottom ◽  
Physical Processes ◽  
Level Change ◽  
Ocean Mass ◽  
The Earth ◽  
Regional Sea Level ◽  
Global Mean

<p>The sea level budget (SLB) equates changes in sea surface height (SSH) to the sum of various geo-physical processes that contribute to sea level change. Currently, it is a common practice to explain a change in SSH as a sum of ocean mass and steric change, assuming that solid-Earth motion is corrected for and completely explained by secular visco-elastic relaxation of mantle, due to the process of glacial isostatic adjustment. Yet, since the Solid Earth also responds elastically to changes in present day mass load near the surface of the Earth, we can expect the ocean bottom to respond to ongoing ocean mass changes. This elastic ocean bottom deformation (OBD) has been ignored until very recently because the contribution of ocean mass to sea level rise was thought to be smaller than the steric contribution and the resulting OBD was within observation system uncertainties. However, ocean mass change has increased rapidly in the last 2 decades. Therefore, OBD is no longer negligible and recent studies have shown that its magnitude is similar to that of the deep steric sea level contribution: a global mean of about 0.1 mm/yr but regional changes at some places can be more than 10 times the global mean. Although now an important part of the SLB, especially for regional sea level, OBD is considered by only a few budget studies and they treat it as a spatially uniform correction. This is due to lack of a mathematical framework that defines the contribution of OBD to the SLB. Here, we use a mass-volume framework to derive, for the first time, a SLB equation that partitions SSH change into its component parts accurately and it includes OBD as a physical response of the Earth system. This updated SLB equation is important for various disciplines of Earth Sciences that use the SLB equation: as a constraint to assess the quality of observational time-series; as a means to quantify the importance of each component of sea level change; and, to adequately include all processes in global and regional sea level projections. We recommend using the updated SLB equation for sea level budget studies. We also revisit the contemporary SLB with the updated SLB equation using satellite altimetry data, GRACE data, and ARGO data.</p>

scholarly journals Sea State Bias Variability in Satellite Altimetry Data

2019 ◽  
Vol 11 (10) ◽  
pp. 1176
Author(s):  
Yongcun Cheng ◽  
Qing Xu ◽  
Le Gao ◽  
Xiaofeng Li ◽  
Bin Zou ◽  
...  
Keyword(s):  
Sea Level ◽  
Sea Level Change ◽  
Sea State ◽  
Mean Sea Level ◽  
Level Change ◽  
Sea State Bias ◽  
Regional Sea Level ◽  
Sea Level Trend ◽  
Global Mean Sea Level ◽  
Global Mean

Sea State Bias (SSB) contributes to global mean sea level variability and it needs cm-level range adjustment due to the instrumental drift over time. To investigate its variations and correct the global and regional sea level trend precisely, we calculate the temporal and spatial variability of the SSB correction in TOPEX, Jason-1, Jason-2 and Jason-3 missions, separately, as well as in the combined missions over the period 1993–2017. The long-term trend in global mean operational 2D non-parametric SSB correction is about −0.03 ± 0.03 mm/yr, which accounts for 1% of current global mean sea level change rate during 1993–2016. This correction contributes to sea level change rates of −1.27 ± 0.21 mm/yr and −0.26 ± 0.13 mm/yr in TOPEX-A and Jason-2 missions, respectively. The global mean SSB varies up to 7–10 mm during the very strong ENSO events in 1997–1998 and 2015–2016. Furthermore, the TOPEX SSB trend, which is consistent with recently reported sea level trend drift during 1993–1998, may leak into the determined global sea level trend in the period. Moreover, the Jason-1/2 zonal SSB variability is highly correlated with the significant wave height (SWH). On zonal average, SSB correction causes about 1% uncertainty in mean sea level trend. At high SWH regions, the uncertainties grow to 2–4% near the 50°N and 60°S bands. This should be considered in the study of regional sea level variability.

scholarly journals Evaluating Model Simulations of Twentieth-Century Sea Level Rise. Part I: Global Mean Sea Level Change

2017 ◽  
Vol 30 (21) ◽  
pp. 8539-8563 ◽  
Author(s):  
Aimée B. A. Slangen ◽  
Benoit Meyssignac ◽  
Cecile Agosta ◽  
Nicolas Champollion ◽  
John A. Church ◽  
...  
Keyword(s):  
Twentieth Century ◽  
Thermal Expansion ◽  
Sea Level Rise ◽  
Sea Level ◽  
Sea Level Change ◽  
Mean Sea Level ◽  
Level Change ◽  
The World ◽  
Global Mean Sea Level ◽  
Global Mean

Sea level change is one of the major consequences of climate change and is projected to affect coastal communities around the world. Here, global mean sea level (GMSL) change estimated by 12 climate models from phase 5 of the World Climate Research Programme’s Climate Model Intercomparison Project (CMIP5) is compared to observational estimates for the period 1900–2015. Observed and simulated individual contributions to GMSL change (thermal expansion, glacier mass change, ice sheet mass change, landwater storage change) are analyzed and compared to observed GMSL change over the period 1900–2007 using tide gauge reconstructions, and over the period 1993–2015 using satellite altimetry estimates. The model-simulated contributions explain 50% ± 30% (uncertainties 1.65 σ unless indicated otherwise) of the mean observed change from 1901–20 to 1988–2007. Based on attributable biases between observations and models, a number of corrections are proposed, which result in an improved explanation of 75% ± 38% of the observed change. For the satellite era (from 1993–97 to 2011–15) an improved budget closure of 102% ± 33% is found (105% ± 35% when including the proposed bias corrections). Simulated decadal trends increase over the twentieth century, both in the thermal expansion and the combined mass contributions (glaciers, ice sheets, and landwater storage). The mass components explain the majority of sea level rise over the twentieth century, but the thermal expansion has increasingly contributed to sea level rise, starting from 1910 onward and in 2015 accounting for 46% of the total simulated sea level change.

Sensitivity of Twenty-First-Century Global-Mean Steric Sea Level Rise to Ocean Model Formulation

2013 ◽  
Vol 26 (9) ◽  
pp. 2947-2956 ◽  
Author(s):  
Robert Hallberg ◽  
Alistair Adcroft ◽  
John P. Dunne ◽  
John P. Krasting ◽  
Ronald J. Stouffer
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Radiative Forcing ◽  
Ocean Model ◽  
First Century ◽  
Model Formulation ◽  
Steric Sea Level ◽  
Near Surface ◽  
Twenty First Century ◽  
Global Mean

Abstract Two comprehensive Earth system models (ESMs), identical apart from their oceanic components, are used to estimate the uncertainty in projections of twenty-first-century sea level rise due to representational choices in ocean physical formulation. Most prominent among the formulation differences is that one (ESM2M) uses a traditional z-coordinate ocean model, while the other (ESM2G) uses an isopycnal-coordinate ocean. As evidence of model fidelity, differences in twentieth-century global-mean steric sea level rise are not statistically significant between either model and observed trends. However, differences between the two models’ twenty-first-century projections are systematic and both statistically and climatically significant. By 2100, ESM2M exhibits 18% higher global steric sea level rise than ESM2G for all four radiative forcing scenarios (28–49 mm higher), despite having similar changes between the models in the near-surface ocean for several scenarios. These differences arise primarily from the vertical extent over which heat is taken up and the total heat uptake by the models (9% more in ESM2M than ESM2G). The fact that the spun-up control state of ESM2M is warmer than ESM2G also contributes by giving thermal expansion coefficients that are about 7% larger in ESM2M than ESM2G. The differences between these models provide a direct estimate of the sensitivity of twenty-first-century sea level rise to ocean model formulation, and, given the span of these models across the observed volume of the ventilated thermocline, may also approximate the sensitivities expected from uncertainties in the characterization of interior ocean physical processes.

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