Dataset: ice_optics
Deployment: LMG0205

From 2001 cruise report: The optics of the different sea ice types found in the region. When weather and day light permitted, snow and ice albedo and transmission measurements were taken. At only one site was the surface frozen where we could measure the combined snow and ice albedo and transmission and then shovel the area and re-measuring to subtract out the snow component. This will allow us to sort out what component the snow and ice have individually in the transmission of light into the ice and water column for the organisms to grow. Our measurements were hampered due to blowing snow which we experienced nearly every day and the fact that we needed to be stopped near solar noon as the sun angle is low this time of year, so only a limited number of optics measurements were performed.

From 2002 cruise report: We also measured the optics of the sea ice using a scanning spectral radiometer. This instrument measures the light levels in 0.5 nanometer increments from 380 to 800 nanometers (visible light through the near infrared). With this instrument we made optical measurements on seven different ice floes. We performed these measurements through the undisturbed snow and ice, and would then shovel off the area to obtain measurements of just the sea ice with no snow cover. We first measured snow and bare ice albedo, then upwelling irradiance at 1 cm increments as we lowered the sensor down through the snow cover. We then would drill a hole in the ice and measure upwelling irradiance at 2 cm to 5 cm increment down through the ice sheet both before and after removing the snow cover. Additionally, the transmission of light through both snow covered sea ice and bare ice was measured.