One of the most visible impacts of climate change in Arctic environments is declining sea ice. Due to an absence of spatially coarse quantitative data, there is a lack of understanding on declining sea ice on a community scale. This study seeks to document historical trends in air temperature, sea ice thickness (SIT), break-up dates (BUDs) and freeze-up dates (FUDs), correlate sea ice behaviour to air temperatures, and document the socio-economic impacts of sea ice change in Resolute Bay Nunavut, using traditional Inuit knowledge (TIK) and scientific methods.
During the scientific portion of this study linear regression, statistical significance, anomaly analysis, and change point detection were used on time series of sea ice concentration (SIC), SIT, and air temperature. Two SIC datasets were accessed to characterize BUDs and FUDs, Canadian Ice Services archived sea ice charts from 1982-2022 and Copernicus Climate Change Services (C3S) gridded satellite derived SIC from 1979-2015. The BUD was defined when SIC fell and stayed below 20%, and the FUD was when SIC returned and stayed above 50%. By applying a statistically significant linear regression to both datasets, the BUD was shown to occur 37.5 days earlier and the FUD occurred 23.4 days later in 2022 than in 1979. This study accessed two SIT datasets, Environment and Climate Change Canada fast ice measurements from 1947-2022 and C3S satellite derived sea ice freeboard measurements from 2002-2020 at four locations in the Barrow Strait. After applying change point detection algorithms, this study found annual maximum fast ice thicknesses increased 32.5 cm from 1948-1981 and decreased 33.2 cm from 1981-2021. Fast ice decreased most substantially in the months of April and May. Sea ice freeboard decreased by 260.8 cm on average from 2002-2020 in the Barrow Strait. Freezing degree days (FDDs) were used to correlate sea ice behaviour to air temperature. As FDDs decrease, sea ice freeboard was the most rapidly changing sea ice parameter and fast ice thickness was most strongly correlated to FDDs. Both these results indicate that air temperature has a greater effect on SIT than the BUD and FUD.
During the TIK investigation of this study, seventeen community members from Resolute Bay, Nunavut, ranging from age 19-81 were interviewed about their perception of changes in SIT, BUD, FUD, and seasonal weather patterns. Participants were interviewed about the socio-economic impacts of sea ice change, traditional Inuit methods of determining thickness, and asked to indicate typical areas of thin and thick ice, areas that break-up and freeze-up first, and hunting and travel routes on printed maps. The interviewees described a decline in sea ice thickness, areas of thin ice in the Barrow Strait, north of Cornwallis Island, and between Bathurst and Devon Island, less frequent use of the sea ice, less traditional food available in the community, increased vessel traffic, a decrease in seal population, new species and birds in the area, and detailed traditional methods of determining ice thickness through observation of color and use of the harpoon.
Agreement between traditional knowledge and the scientific data was present in typical break-up and freeze-up patterns, and annual maximum thickness decreasing over time. While most respondents indicated FUD was later and BUD earlier, more participants responded there have been changes to the FUD than the BUD, whereas the scientific data showed more severe changes to the BUD than FUD. During interviews, there was consensus that summer temperatures are getting warmer but there was variability in responses when asked about winter temperatures. The scientific results showed less warming in the summer (Jun-Aug) than winter months (Jan-Mar) with the most warming in the fall (Sept-Nov). The lack of agreement between these results could be attributed to local perceived changes to winter weather referring to storminess rather than strictly temperature. TIK provided small scale information about the sea ice that the current state of scientific observation can not. In conclusion, a more holistic understanding of sea ice behaviour can be achieved by including Inuit traditional knowledge in partnership with scientific methods.
| Identifer | oai:union.ndltd.org:uottawa.ca/oai:ruor.uottawa.ca:10393/45665 |
| Date | 27 November 2023 |
| Creators | Forsythe, Alexandra |
| Contributors | Nistor, Ioan |
| Publisher | Université d'Ottawa / University of Ottawa |
| Source Sets | Université d’Ottawa |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | application/pdf |
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