Dynamics of crystal formation in the Greenland NorthGRIP ice core
Journal of Glaciology, Vol 50, No. 170, p. 325-328, 2004Joachim Mathiesen, Jesper Ferkinghoff-Borg, Mogens H. Jensen, Mogens Levinsen and Poul Oleseno
The Niels Bohr Institute, Blegdamsvej 17, DK-2100 Copenhagen, Denmark
Dorthe Dahl-Jensen and Anders Svensson
Ice and Climate, The Niels Bohr Institute, Juliane Maries Vej 30, DK-2100 Copenhagen, Denmark
ABSTRACT.
The North Greenland Icecore Project (NorthGRIP) ice core provides
palaeoclimatic information back to about 120 kyr BP. The size
distributions of ice crystals
in the upper 880 m of the NorthGRIP ice core, which cover a time-span
of approximately 5300 years, have been obtained previously. The
distributions evolve
towards a universal curve, indicating a common underlying physical
process in the formation of crystals. We identify this process as an
interplay between
fragmentation of the crystals and diffusion of their grain boundaries.
The process is described by a two-parameter differential equation to
which we obtain
the exact solution. The solution is in excellent agreement with the
measured distributions.