scholarly journals Understanding the Uncertainty in the 21st Century Dynamic Sea Level Projections: The Role of the AMOC

2019 ◽  
Vol 46 (1) ◽  
pp. 210-217 ◽  
Author(s):  
Changlin Chen ◽  
Wei Liu ◽  
Guihua Wang
Keyword(s):  
Sea Level ◽  
21St Century ◽  
Dynamic Sea Level

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.

Smoke on the Water

2017 ◽  
Author(s):  
Jason O'Donoughue
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
21St Century ◽  
River Valley ◽  
Ecological Conditions ◽  
Spring Flow ◽  
Holocene Sea Level

This chapter introduces the book and gives an overview of the importance of Florida’s springs, the threats facing them in the 21st century, and the ways that springs have typically figured into archaeological narratives. In particular, it discusses the role of springs in the inception of shell mounding during the Mount Taylor period (7400–4600 cal BP) in the St. Johns River valley of northeast Florida. It has long been argued that the onset of spring flow, itself a result of Holocene sea-level rise, created the necessary ecological conditions for human exploitation of molluscs and the deposition of their shells in mounds and middens. The chapter provides a preliminary critique of this model, discusses the major arguments of the book, and closes with an outline of the remaining chapters.

scholarly journals Emulating Atlantic overturning strength for low emission scenarios: consequences for sea-level rise along the North American east coast

2010 ◽  
Vol 1 (1) ◽  
pp. 357-384
Author(s):  
C. F. Schleussner ◽  
K. Frieler ◽  
M. Meinshausen ◽  
J. Yin ◽  
A. Levermann
Keyword(s):  
New York ◽  
New York City ◽  
Sea Level Rise ◽  
Sea Level ◽  
21St Century ◽  
York City ◽  
Meridional Overturning Circulation ◽  
Future Evolution ◽  
The Future ◽  
Dynamic Sea Level

Abstract. In order to provide probabilistic projections of the future evolution of the Atlantic Meridional Overturning Circulation (AMOC), we calibrated a simple Stommel-type box model to emulate the output of fully coupled three-dimensional atmosphere-ocean general circulation models (AOGCMs) of the Coupled Model Intercomparison Project (CMIP). Based on this calibration to idealised global warming scenarios with and without interactive atmosphere-ocean fluxes and freshwater perturbation simulations, we project the future evolution of the AMOC within the covered calibration range for the lower two Representative Concentration Pathways (RCPs) until 2100 obtained from MAGICC6. For RCP3-PD with a global mean temperature median below 1.0 °C warming relative to the year 2000, we project an ensemble median weakening of up to 11% compared to 22% under RCP4.5 with a warming median up to 1.9 °C over the 21st century. Additional Greenland melt water of 10 and 20 cm of global sea-level rise equivalent further weakens the AMOC by about 4.5 and 10%, respectively. By combining our outcome with a multi-model sea-level rise study we project a dynamic sea-level rise along the New York City coastline of 4 cm for the RCP3-PD and of 8 cm for the RCP4.5 scenario over the 21st century. We estimate the total steric and dynamic sea-level rise for New York City to be about 24 cm till 2100 for the RCP3-PD scenario, which can hold as a lower bound for sea-level rise projections in this region.

Role of Regional Ocean Dynamics in Dynamic Sea Level Projections by the end of the 21st Century over Southeast Asia

2021 ◽  
Author(s):  
Dhrubajyoti Samanta ◽  
Svetlana Jevrejeva ◽  
Hindumathi K. Palanisamy ◽  
Kristopher B. Karnauskas ◽  
Nathalie F. Goodkin ◽  
...  
Keyword(s):  
Southeast Asia ◽  
Sea Level ◽  
Ocean Dynamics ◽  
Model Intercomparison ◽  
Intercomparison Project ◽  
Projected Changes ◽  
Mean State ◽  
Dynamic Sea Level ◽  
The Tropical Pacific

<p>Southeast Asia is especially vulnerable to the impacts of sea-level rise due to the presence of many low-lying small islands and highly populated coastal cities. However, our current understanding of sea-level projections and changes in upper-ocean dynamics over this region currently rely on relatively coarse resolution (~100 km) global climate model (GCM) simulations and is therefore limited over the coastal regions. Here using GCM simulations from the High-Resolution Model Intercomparison Project (HighResMIP) of the Coupled Model Intercomparison Project Phase 6 (CMIP6) to (1) examine the improvement of mean-state biases in the tropical Pacific and dynamic sea-level (DSL) over Southeast Asia; (2) generate projection on DSL over Southeast Asia under shared socioeconomic pathways phase-5 (SSP5-585); and (3) diagnose the role of changes in regional ocean dynamics under SSP5-585. We select HighResMIP models that included a historical period and shared socioeconomic pathways (SSP) 5-8.5 future scenario for the same ensemble and estimate the projected changes relative to the 1993-2014 period. Drift corrected DSL time series is estimated before examining the projected changes. Due to improved simulation of heat, salt, and mass distribution in the ocean, HighResMIP models not only reduce mean state biases in the tropical Pacific (such as cold-tongue sea surface temperature bias), but also near Southeast Asia including DSL. Despite intermodel diversity, there is an overall agreement of increasing sea-level over Southeast Asia. The multimodel ensemble of HighResMIP models suggests a rise of 0.2 m sea level in dynamic sea level (combined with thermosteric component) over Southeast Asia by 2070. Sea-level rises further up to 0.5 m by the end of the 21<sup>st</sup> century. Further, we found regional heat and mass transport changes have a major role in the projected sea-level pattern over Southeast Asia. For example, heat convergence to the east of Vietnam can account for most of the sea-level rise in the region. Our study can provide better insight into the contribution of regional ocean dynamics to DSL projections and useful to suggest for further ocean modelling studies.</p>

scholarly journals Emulating Atlantic overturning strength for low emission scenarios: consequences for sea-level rise along the North American east coast

2011 ◽  
Vol 2 (2) ◽  
pp. 191-200 ◽  
Author(s):  
C. F. Schleussner ◽  
K. Frieler ◽  
M. Meinshausen ◽  
J. Yin ◽  
A. Levermann
Keyword(s):  
New York ◽  
New York City ◽  
Sea Level Rise ◽  
Sea Level ◽  
21St Century ◽  
York City ◽  
Meridional Overturning Circulation ◽  
Future Evolution ◽  
The Future ◽  
Dynamic Sea Level

Abstract. In order to provide probabilistic projections of the future evolution of the Atlantic Meridional Overturning Circulation (AMOC), we calibrated a simple Stommel-type box model to emulate the output of fully coupled three-dimensional atmosphere-ocean general circulation models (AOGCMs) of the Coupled Model Intercomparison Project (CMIP). Based on this calibration to idealised global warming scenarios with and without interactive atmosphere-ocean fluxes and freshwater perturbation simulations, we project the future evolution of the AMOC mean strength within the covered calibration range for the lower two Representative Concentration Pathways (RCPs) until 2100 obtained from the reduced complexity carbon cycle-climate model MAGICC 6. For RCP3-PD with a global mean temperature median below 1.0 °C warming relative to the year 2000, we project an ensemble median weakening of up to 11% compared to 22% under RCP4.5 with a warming median up to 1.9 °C over the 21st century. Additional Greenland meltwater of 10 and 20 cm of global sea-level rise equivalent further weakens the AMOC by about 4.5 and 10%, respectively. By combining our outcome with a multi-model sea-level rise study we project a dynamic sea-level rise along the New York City coastline of 4 cm for the RCP3-PD and of 8 cm for the RCP4.5 scenario over the 21st century. We estimate the total steric and dynamic sea-level rise for New York City to be about 24 cm until 2100 for the RCP3-PD scenario, which can hold as a lower bound for sea-level rise projections in this region, as it does not include ice sheet and mountain glacier contributions.

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

Ocean Science ◽  
2014 ◽  
Vol 10 (3) ◽  
pp. 485-500 ◽  
Author(s):  
T. Howard ◽  
J. Ridley ◽  
A. K. Pardaens ◽  
R. T. W. L. Hurkmans ◽  
A. J. Payne ◽  
...  
Keyword(s):  
Sea Level ◽  
21St Century ◽  
Sea Level Change ◽  
Sea Level Changes ◽  
Mean Sea Level ◽  
Ice Melt ◽  
Level Change ◽  
Global Mean Sea Level ◽  
Global Mean ◽  
Dynamic Sea Level

Abstract. Climate change has the potential to influence global mean sea level through a number of processes including (but not limited to) thermal expansion of the oceans and enhanced land ice melt. In addition to their contribution to global mean sea level change, these two processes (among others) lead to local departures from the global mean sea level change, through a number of mechanisms including the effect on spatial variations in the change of water density and transport, usually termed dynamic sea level changes. In this study, we focus on the component of dynamic sea level change that might be given by additional freshwater inflow to the ocean under scenarios of 21st-century land-based ice melt. We present regional patterns of dynamic sea level change given by a global-coupled atmosphere–ocean climate model forced by spatially and temporally varying 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 mean sea level rise over the 21st century. The temporal evolution of the dynamic sea level changes, in the presence of considerable variations in the ice melt flux, is also 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 amounting to 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 CO2 or under a business-as-usual greenhouse gas warming scenario of increasing CO2.

Glacial Contributions to 21st Century Sea Level Rise

Eos ◽  
2020 ◽  
Vol 101 ◽  
Author(s):  
Kate Wheeling
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
21St Century ◽  
Mass Change ◽  
Sources Of Uncertainty

Researchers identify the main sources of uncertainty in projections of global glacier mass change, which is expected to add about 8–16 centimeters to sea level, through this century.

Desecularization as Phenomenon at the Turn of 21st Century

2019 ◽  
Vol 29 ◽  
pp. 49-57
Author(s):  
Sergey V.  Lebedev ◽  
Galina N.  Lebedeva
Keyword(s):  
21St Century ◽  
Social Problems ◽  
European Countries ◽  
Islamic Revolution ◽  
Islamic Movement ◽  
The World ◽  
Rational Alternative ◽  
Role Of Religion

In the article the authors note that since the 1970s, with the rise of the Islamic movement and the Islamic revolution in Iran, philosophers and political scientists started to talk about religious renaissance in many regions of the world. In addition, the point at issue is the growing role of religion in society, including European countries that have long ago gone through the process of secularization. The reasons for this phenomenon, regardless of its name, are diverse, but understandable: secular ideologies of the last century failed to explain the existing social problems and give them a rational alternative.

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