Ice core characteristics from the Belcher Islands and Sanikiluaq, NU.

As part of a community-based sea ice and ocean monitoring program in the community of Sanikiluaq, NU and the greater area of the Belcher Islands in subarctic Hudson Bay, field observations were collected on landfast first-year sea ice between March and May in 2019 and 2022 and in March 2023. The observations include snow thickness, ice thickness, ice growth rates, and a number of auxiliary parameters such as local wind speed and direction, air temperature and pressure, and surface ocean salinity and temperature. In 2019, to capture changes in the ice composition during the seasonal transitions, 50 cm ice cores of the upper sea ice cover were collected every second day, and a full ice core was collected every 8th day. Measurements of temperature, salinity and stable isotopes in the ice cores were made on defined 2 cm sections in the upper 50 cm of the ice cores and then every 5 cm throughout the remaining length of the core. In 2022, twenty-two ice cores were collected at different distances from a recurrent polynya and in a protected area far away of the polynya influence with the aim of investigating to what extent the under-ice water conditions influence ice growth. Sixteen of these ice cores were sawed into 5 cm sections from surface to bottom, four ice cores were kept whole for textural analysis, and two ice cores were lost. In 2023, to complement the data collected in 2022, seven ice cores were collected and kept whole to be analyzed for salinity, stable isotopes, and textural analyses. Salinity and stable isotopes were measured at the University of Manitoba on melted ice core sections. PhD student Aura Diaz is currently working with these stable isotope data and various models of ice growth to reconstruct rates of ice growth and quantify the incorporation of river water into growing sea ice.