Sökning: "ice dynamics"

Visar resultat 11 - 15 av 114 avhandlingar innehållade orden ice dynamics.

1. 11. Sea Ice Concentration Estimation and Ice Type Classification from Dual-Frequency Satellite Synthetic Aperture Radar

   Författare :Wiebke Aldenhoff; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; sea ice concentration; sea ice; SAR imaging; sea ice classification; Fram Strait;

   Sammanfattning : The sea ice cover in the Arctic has undergone dramatic changes in recent years. The perennial sea ice extent is decreasing by 12.2 % per decade while annual mean sea ice thickness has decreased by more than 2 m for the central Arctic Basin from 1975 to 2012. LÄS MER

3. 12. Late Quaternary ice sheet history and dynamics in central and southern Scandinavia

   Författare :Timothy Johnsen; Helena Alexanderson; James T. Teller; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Scandinavian ice sheet; ice sheet dynamics; luminescence dating; cosmogenic exposure dating; geochronology; moraine; interstadial; deglaciation; nunatak; Quaternary geology; Kvartärgeologi; kvartärgeologi; Quarternary Geology;

   Sammanfattning : Recent work suggests an emerging new paradigm for the Scandinavian ice sheet (SIS); one of a dynamically fluctuating ice sheet. This doctoral research project explicitly examines the history and dynamics of the SIS at four sites within Sweden and Norway, and provides results covering different time periods of glacial history. LÄS MER

4. 13. 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

5. 14. X-ray scattering and spectroscopy of supercooled water and ice

   Författare :Jonas A. Sellberg; Anders Nilsson; Lars G. M. Pettersson; Thomas Loerting; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; supercooled water; ice; x-ray scattering; x-ray spectroscopy; free-electron laser; kemisk fysik; Chemical Physics;

   Sammanfattning : This thesis presents experimental studies of water and ice at near-atmospheric pressures using intense x-rays only accessible at synchrotrons and free-electron lasers. In particular, it focuses on the deeply supercooled, metastable state and its implications on ice nucleation. LÄS MER

7. 15. Towards Single Molecule Imaging - Understanding Structural Transitions Using Ultrafast X-ray Sources and Computer Simulations

   Författare :Carl Caleman; Janos Hajdu; Richard Neutze; Uppsala universitet; []
   Nyckelord :Molecular biophysics; XFEL; Ultrafast Melting; InSb; Molecular Dynamics; Water Cluster; Evaporation; Secondary Electron; Photo-cathode; Electron Scattering; Energy Loss Function; Single Particle Imaging; X-ray Diffraction; Water; Ice; KI; CsI; Molekylär biofysik;

   Sammanfattning : X-ray lasers bring us into a new world in photon science by delivering extraordinarily intense beams of x-rays in very short bursts that can be more than ten billion times brighter than pulses from other x-ray sources. These lasers find applications in sciences ranging from astrophysics to structural biology, and could allow us to obtain images of single macromolecules when these are injected into the x-ray beam. LÄS MER