Views of arctic lakes from an oblique photograph in the late spring showing differential iceout timing (A), using synthetic aperture radar (SAR, white lakes are floating ice an black bedfast ice) (B), using multi-year SAR imagery to classify ice-regimes from Arp et al. 2012a (C).
Shallow lakes and ponds may cover up to 40% of the land surface in Arctic lowland regions. Many of these water bodies traditionally freeze solid (bedfast ice) during the winter, preserving sublake permafrost and keeping soil C stocks immobile at depth. Slightly deeper lakes maintain some liquid water beneath floating ice, causing deep thaw zones (taliks) in otherwise continuous permafrost.
Evidence suggests that thinner ice growth in response to warmer, snowier winters is pushing many bedfast ice lakes to floating ice regimes. If such a regime shift becomes pervasive across lake-rich landscapes, resulting permafrost thaw and enhanced moisture and heat flux could generate positive feedbacks, further amplifying this regime change.
This project examines the extent and dynamics of bedfast and floating ice lakes in relation to hypothesized interactions and feedback with permafrost and climate. A combination of remote sensing, field monitoring and geophysical measurements, experiments and physical models will be used to isolate processes, quantify interactions and project changes. Project findings will be relevant locally for native village subsistence and for water supply to the petroleum industry, and globally for scientists studying permafrost thaw and Arctic climate change.
Continuum of the ice regimes of shallow Arctic lakes with changes in fundamental drivers (A) and hypothesized interactions with permafrost (B) and atmosphere and water balance (C).