Analysis of optical beam spread measurements in sea ice with modelled physical properties

Optical beam spread measurements are considered to be a primary source of information to characterize scattering processes in sea ice. Beam transmission and spread measurements have been made through the ice sheet by placing a 532 nm [Nd:YAG] laser source below the ice/water interface and measuring the upward irradiance along a diameter through the surface pattern. In sea ice scattering properties described by the bulk scattering coefficient are highly dependent on the intricate structural features such as air bubbles, brine pockets and channels, and internal platelet boundaries. Variability in optical properties is associated with morphological changes to these ice structural features during growth phases and thermal cycling. Improvement in the understanding how scattering relates to physical properties is being gained by application of Monte Carlo modeling to the structure as horizontal layers with uniform scattering properties or as vertical platelet structures.