Facing Arctic Climate Change: Sea Ice Freeze Through the Lens of A Community

Abstract

Arctic sea ice loss has significantly affected the wellbeing of Arctic Indigenous communities due to subsistence-based lifeways that depend on the land and ocean in remote coastal locations. Through conversations with community members of Kivalina, Alaska, a main area of research emerged as high priority: understanding changes in and determining predictability of sea ice freeze timing, or ice advance day (IAD). We find IAD at Kivalina occurs on average on November 12 from 1980-2019 and has shifted in time on average one day later per year over the same period; nonuniformity in significant IAD correlation to Kivalina IAD throughout the Chukchi and Bering Seas suggest that looking closer at local, rather than regional, scales is necessary. We analyze observations and find 500 hPa geopotential height and temperature at 850 hPa to be most relevant to IAD timing approximately a month before the IAD due to increased anomalies directly preceding the IAD, contrasting with previous scholarship’s 2-3 month lead times of atmospheric predictors. We compare observations with data from a large ensemble of a climate model (CESM2-LE), which has longer-lasting predictor memory and increased temporal and spatial correlation to Kivalina IAD. We find linear regression forecasts predicting Kivalina IAD with monthly means of daily detrended anomalies of sea surface temperatures (SST) and ocean heat content perform with near 7 days of error for forecasts initialized one month before the IAD in both observations and the model. We assess observational uncertainty in SST and find IAD freezing at unphysical SST, suggesting a need for more accurate observations. Our results encourage community-centric Arctic co-production research in order to ensure that future scholarship is useful to those most affected by climate change.