Sökning: "ice sheet modelling"

Visar resultat 1 - 5 av 13 avhandlingar innehållade orden ice sheet modelling.

1. 1. 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

3. 2. Numerical modelling of the Cordilleran ice sheet

   Författare :Julien Seguinot; Arjen Stroeven; Shawn Marshall; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Numerical modelling; Cordilleran ice sheet; last glacial cycle; Physical Geography; naturgeografi;

   Sammanfattning : This doctoral dissertation presents a study of the glacial history of the North American Cordillera using numerical ice sheet modelling calibrated against field evidence. This area, characterized by the steep topography of several mountain ranges separated by large inter-montane depressions, was once covered by a large-scale ice mass: the former Cordilleran ice sheet. LÄS MER

4. 3. Hydrology and Bed Topography of the Greenland Ice Sheet : Last known surroundings

   Författare :Katrin Lindbäck; Rickard Pettersson; Francisco Navarro; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; climate change; Greenland Ice Sheet; radio-echo sounding; digital elevation models; ice thickness; bed topography; spectral analysis; roughness; subglacial hydrology; water piracy; englacial features; drainage catchments; meltwater runoff; ice dynamics; klimatförändringar; Grönlands inlandsis; markbaserad radar; digitala höjdmodeller; istjocklek; bottentopografi; spektralanalys; subglacial hydrologi; englaciala strukturer; avrinningsområden; isdynamik;

   Sammanfattning : The increased temperatures in the Arctic accelerate the loss of land based ice stored in glaciers. The Greenland Ice Sheet is the largest ice mass in the Northern Hemisphere and holds ~10% of all the freshwater on Earth, equivalent to ~7 metres of global sea level rise. LÄS MER

5. 4. Ice Sheet, Climate, and Landscape Interactions in Dronning Maud Land, Antarctica

   Författare :Jens-Ove Näslund; Sugden David; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Antarctica; Basal temperature; Dronning Maud Land; Erosion; Escarpments; Glacial landforms; Ice Sheets; Ice sheet modelling; Landscape development; Palaeosurfaces; Radar; Other earth sciences; Övrig geovetenskap; naturgeografi; Physical Geography;

   Sammanfattning : The impact of glaciers and ice sheets on the subglacial landscape are of fundamental importance for studies of glacial history and landscape development, both in previously glaciated areas and in areas that are glaciated today. The thesis concerns the present and past erosive capacity of the ice sheet in Dronning Maud Land, East Antarctica. LÄS MER

7. 5. Subsurface fluxes of mass and energy at the accumulation zone of Lomonosovfonna ice cap, Svalbard

   Författare :Sergey Marchenko; Veijo Pohjola; Rickard Pettersson; Carleen Reijmer; Thomas Schuler; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; glacier; ice sheet; sea level; runoff; ice; firn; snow; stratigraphy; density; core; radar; thermistor; temperature; preferential water flow; thermal conductivity; water content; Geovetenskap med inriktning mot naturgeografi; Earth Science with specialization in Physical Geography;

   Sammanfattning : Glaciers cover ca 10% of the Earth's land and are found in the high altitudes and latitudes. They are important components of environmental systems due to the multiple feedbacks linking them with the atmosphere, hydrosphere and periglacial landscapes. LÄS MER