Measurements of spectral transmission and backscattering of light in first year sea ice, Tent Island, McMurdo Sound

In situ measurements of the the spectral transmission and backscattering of light was conducted on first year ice to characterise the optical properties of sea ice. The average scattering length and attenuation length was determined for 13 wavelength bands in the wave length range between 400nm to 1100nm. A weakly divergent monochromatic light source was placed on the surface of the ice and the emergent radiation field was measured at both the top and bottom surfaces of the ice. Salinity, temperature (as a function of depth) and the structure of the sea ice was recorded to aid determination of results. Measurements were repeated numerous times at various sites over two seasons. The time periods that were spent making measurements allowed an investigation of the effects of an increase in atmospheric temperature, which in turn increased ice temperature and changed the results.