Ice Formation in Norwegian Fjords – Findings from the 2018 - 2019 Field Season

Understanding ice conditions in fjords is imperative to ensure safe operations and to protect the surrounding environment. Seven fjords in northern Norway were visited in March 2019, six with significant ice cover. In each location, measurements of ocean temperature and salinity, and δ18O for ocean water and river water leading into the fjords were gathered. In addition, where ice was present, measurements of ice bulk salinity and δ18O were obtained along with an extra core to examine ice stratigraphy and pore structure. Results show ice of low bulk salinity, < 1.5 psu, and δ18O, < -7.67 ‰, in five fjords holding ice with maximum ice thickness being upwards of 0.46 m. This result combined with examination of stratigraphy cores reveals ice closely resembling freshwater ice in structure despite lying atop an ocean of average salinity 32 – 33.5 (psu). Ice salinity profiles elude to varying environmental conditions impacting ice formation throughout the winter season. Due to the impact of significant freshwater flux, ice properties differed significantly from sea ice forming in the open ocean, an important characteristic when considered in application to coastal operations