Sökning: "ice sheet modeling"

Visar resultat 1 - 5 av 8 avhandlingar innehållade orden ice sheet modeling.

1. 1. Numerical ice sheet modeling : Forward and inverse problems

   Författare :Gong Cheng; Lina von Sydow; Per Lötstedt; Nina Kirchner; Irina Tezaur; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; ice sheet modeling; finite element method; grounding line migration; inverse problems; adjoint method; Scientific Computing; Beräkningsvetenskap;

   Sammanfattning : Ice sheets have strong influence on the climate system. Numerical simulation provides a mathematical tool to study the ice dynamics in the past and to predict their contribution to climate change in the future. Large scale ice sheets behave as incompressible non-Newtonian fluid. LÄS MER

3. 2. Computational Ice Sheet Dynamics : Error control and efficiency

   Författare :Josefin Ahlkrona; Per Lötstedt; Jesse Johnson; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ice sheet modelling; stokes equations; shallow ice approximation; finite element method; perturbation expansions; non-newtonian fluids; free surface flow; Scientific Computing; Beräkningsvetenskap;

   Sammanfattning : Ice sheets, such as the Greenland Ice Sheet or Antarctic Ice Sheet, have a fundamental impact on landscape formation, the global climate system, and on sea level rise. The slow, creeping flow of ice can be represented by a non-linear version of the Stokes equations, which treat ice as a non-Newtonian, viscous fluid. LÄS MER

4. 3. Stability of the free-surface problem arising in ice-sheet- and glacier modeling : Numerical investigation and stabilization

   Författare :André Löfgren; Josefin Ahlkrona; Fabien Gillet-Chaulet; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Ice-sheet modeling; glacier modeling; ice-sheet dynamics; free-surface flow; stability; stabilization; free-surface stabilization algorithm; Numerical Analysis; numerisk analys;

   Sammanfattning : This thesis consists of two papers dealing with a stabilization method for free-surface flows. The method was initially developed to stabilize mantle-convection simulations, but is in this work extended to ice-sheet- and glacier modeling. LÄS MER

5. 4. On the Late Saalian glaciation : A climate modeling study

   Författare :Florence Colleoni; Martin Jakobsson; Johan Nilsson; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Climate modeling; Eurasian ice sheet; Quaternary; Saalian; surface mass balance; SST; Earth sciences; Geovetenskap; Marine Geoscience; marin geovetenskap;

   Sammanfattning : This thesis focuses on the glaciation of the Late Saalian period (160 -140 ka) over Eurasia. The Quaternary Environment of the Eurasian North (QUEEN) project determined that during this period, the Eurasian ice sheet was substantially larger than during the entire Weichselian cycle and especially that of the Last Glacial Maximum (21 ka, LGM). LÄS MER

7. 5. Deglacial impact of the Scandinavian Ice Sheet on the North Atlantic climate system

   Författare :Francesco Muschitiello; Barbara Wohlfarth; Raimund Muscheler; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; climate; North Atlantic; last deglaciation; isotope geochemistry; chronology; climate modeling; Marine Geology; maringeologi;

   Sammanfattning : The long warming transition from the Last Ice Age into the present Interglacial period, the last deglaciation, holds the key to our understanding of future abrupt climate change. In the last decades, a great effort has been put into deciphering the linkage between freshwater fluxes from melting ice sheets and rapid shifts in global ocean-atmospheric circulation that characterized this puzzling climate period. LÄS MER