The distribution of path lengths taken by light as it scatters through sea ice

The spatial spreading of light introduced at a point on the surface of the ice and the temporal spreading of a brief pulse of light injected at a point was measured to clarify the details of the interaction of light with ice. The distribution of path lengths taken by light as it scatters randomly through sea ice was investigated by introducing a very short burst of light (3 x 10-9) into the surface, and measuring the straggling in the emergent pulse at some distance (100-500mm) from the source. This was repeated several times throughout the study period and many spectra were collected. Salinity, temperature and ice density was continuously monitored from cores to relate the optical behaviour to the physical structure of the ice. This experiment was repeated at two different sites, site a on typical first year sea ice of 2m thickness and site B on 0.88m thick ice, near the ice edge which did not have the highly disordered frozen grease ice layer of site A.