DOI: 10.5884/13323
title:  Ice core characteristics from the Belcher Islands and Sanikiluaq, NU.

description: 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.
description: The objective of this study is to gather landfast ice data in collaboration with a community-based monitoring program based out of Sanikiluaq, NU. Community members observed differences in the thickness and properties of the ice during some years that they considered possibly related to changes in the properties of the water underlying the ice or changes in currents and circulation. Previous studies have found that the area south and east of the Belcher Islands has shallow stratification throughout winter because of accumulation of river water originating in James Bay. A shallow subsurface water mass at a depth of ~ 30 m also contains remnant heat from the previous summer, which may affect ice properties at sites of upwelling. The landfast ice data and observations collected at the Belcher Islands comprise part of the PhD thesis research of University of Manitoba student Aura Diaz. Among her research interests is the response of sea ice to changes in high-latitude climate- and marine systems, and the role of sea ice in providing feedbacks to these processes. Her observations of ice and auxiliary parameters (snow, winds, air temperatures, surface water temperature and salinity, etc.) seek to improve understanding of how the environmental factors of the atmosphere (temperature, wind, etc.) and ocean (salinity, circulation, etc.) control sea ice growth and melt, and how the structure and properties of the sea ice are affected. This research helps address major gaps in our understanding of atmosphere-ice-ocean interactions and how changing sea ice feedback processes, in turn, modify these atmospheric and oceanic environmental factors. A more complete understanding of the processes connecting the atmosphere, sea ice and ocean will help improve how landfast ice, especially in areas with significant river water presence in winter, is represented in Earth System models.