scholarly journals The motion of ice stream margins

2013 ◽  
Vol 714 ◽  
pp. 1-4 ◽  
Author(s):  
A. C. Fowler

AbstractThe recent article by Schoof (J. Fluid Mech., vol. 712, 2012, pp. 552–578) provides a technically demanding solution to the problem of determining ice-stream margin evolution. It is important in opening the way to the future theoretical description of how the ice sheets will melt and sea level will rise as the climate warms. But the sophistication of the mathematics should not operate as a mask to an examination of the credibility of the model.

Author(s):  
John Thomas Riley

Although the future of society is hazy, a workable vision of the future can be developed from existing computer modeling of key parameters like population and sea level. This vision is referred to in this chapter as the driven future. The future of humans and artificial intelligence (AI) is then reconsidered from within the context of this driven future. Specific examples of how AIs might be utilized to address real human problems in this future are developed. The modifications to the way humans and AIs interact to facilitate addressing major problems is then discussed, including the human/machine symbiosis and the application of corporate persons directly to AIs.


2014 ◽  
Author(s):  
Bette Otto-Bliesner ◽  
William Lipscomb ◽  
Shawn Marshall ◽  
William Sacks ◽  
Jeremy Fyke ◽  
...  

2016 ◽  
Vol 12 (12) ◽  
pp. 2195-2213 ◽  
Author(s):  
Heiko Goelzer ◽  
Philippe Huybrechts ◽  
Marie-France Loutre ◽  
Thierry Fichefet

Abstract. As the most recent warm period in Earth's history with a sea-level stand higher than present, the Last Interglacial (LIG,  ∼  130 to 115 kyr BP) is often considered a prime example to study the impact of a warmer climate on the two polar ice sheets remaining today. Here we simulate the Last Interglacial climate, ice sheet, and sea-level evolution with the Earth system model of intermediate complexity LOVECLIM v.1.3, which includes dynamic and fully coupled components representing the atmosphere, the ocean and sea ice, the terrestrial biosphere, and the Greenland and Antarctic ice sheets. In this setup, sea-level evolution and climate–ice sheet interactions are modelled in a consistent framework.Surface mass balance change governed by changes in surface meltwater runoff is the dominant forcing for the Greenland ice sheet, which shows a peak sea-level contribution of 1.4 m at 123 kyr BP in the reference experiment. Our results indicate that ice sheet–climate feedbacks play an important role to amplify climate and sea-level changes in the Northern Hemisphere. The sensitivity of the Greenland ice sheet to surface temperature changes considerably increases when interactive albedo changes are considered. Southern Hemisphere polar and sub-polar ocean warming is limited throughout the Last Interglacial, and surface and sub-shelf melting exerts only a minor control on the Antarctic sea-level contribution with a peak of 4.4 m at 125 kyr BP. Retreat of the Antarctic ice sheet at the onset of the LIG is mainly forced by rising sea level and to a lesser extent by reduced ice shelf viscosity as the surface temperature increases. Global sea level shows a peak of 5.3 m at 124.5 kyr BP, which includes a minor contribution of 0.35 m from oceanic thermal expansion. Neither the individual contributions nor the total modelled sea-level stand show fast multi-millennial timescale variations as indicated by some reconstructions.


2018 ◽  
pp. 469-475
Author(s):  
Philip L. Gibbard ◽  
Jane E. Rawson ◽  
Alan G. Smith

Author(s):  
Ian Allison ◽  
William Colgan ◽  
Matt King ◽  
Frank Paul
Keyword(s):  

2020 ◽  
Vol 14 (9) ◽  
pp. 2819-2833
Author(s):  
Surendra Adhikari ◽  
Erik R. Ivins ◽  
Eric Larour ◽  
Lambert Caron ◽  
Helene Seroussi

Abstract. Polar ice sheets are important components of the Earth system. As the geometries of land, ocean and ice sheets evolve, they must be consistently captured within the lexicon of geodesy. Understanding the interplay between the processes such as ice-sheet dynamics, solid-Earth deformation, and sea-level adjustment requires both geodetically consistent and mass-conserving descriptions of evolving land and ocean domains, grounded ice sheets and floating ice shelves, and their respective interfaces. Here we present mathematical descriptions of a generic level set that can be used to track both the grounding lines and coastlines, in light of ice–ocean mass exchange and complex feedbacks from the solid Earth and sea level. We next present a unified method to accurately compute the sea-level contribution of evolving ice sheets based on the change in ice thickness, bedrock elevation and mean sea level caused by any geophysical processes. Our formalism can be applied to arbitrary geometries and at all timescales. While it can be used for applications with modeling, observations and the combination of two, it is best suited for Earth system models, comprising ice sheets, solid Earth and sea level, that seek to conserve mass.


Author(s):  
A. Berger ◽  
TH. Fichefet ◽  
H. Gallee ◽  
I. Marsiat ◽  
CH. Tricot ◽  
...  

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