Abstract
Snow impacts sea ice, it insulates the sea ice beneath and reflects sunlight from above, thus controlling the formation rate of sea ice in winter and the melt rate in summer. There is currently a large degree of uncertainty about the depth of snow on sea ice as it cannot be directly measured from satellites, and in situ measurements are sparse and biased towards spring and summer observations. This often necessitates the use of poorly constrained modelled snow depths, leading to significant bias in model representations of sea ice cover. As a part of the University of Otago Aotearoa New Zealand Sea Ice Mass Balance Station, acoustic snow depth sensors have been installed on the McMurdo Sound land-fast sea ice every winter since 2017. However, the sensors have been intermittently failing and short-lived. This research began by processing three years of snow depth data derived from an acoustic sensor at the SIMBS. This led me to test the acoustic sensors in a laboratory environment to determine why they were failing. I found that the acoustic sensors were not being used correctly and were poorly maintained, but work reliably when installed and used correctly. I made improvements to the way the acoustic sensors were used, and facilitated the deployment of the acoustic sensor at the SIMBS in 2020. I identified the need for an inexpensive alternative to the acoustic sensors, and subsequently developed a laser snow sensor. I tested the laser sensor in the laboratory before deploying it over snow, in an alpine environment in New Zealand. I found that an inexpensive laser sensor is a viable option for measuring snow depth on sea ice.