Long-term (2000-2017) response of lake-bottom temperature to climate variation in two adjacent tundra lakes, western Arctic coast, Canada

Lakes are principal agents of disturbance to permafrost. Many Arctic lakes are well-mixed in summer, so lake-bottom temperature is associated with thaw-season climate. In winter, the thermal regimes of the atmosphere and lake-bottoms are distinct. Measurements of bottom temperatures on shallow near-shore terraces and in deep central pools at two tundra lakes show lake regime responses to climate variation. Annual mean temperatures have varied in 2000-17 between -5.7 and 2.8 Celsius (°C) for shallow terraces and 1.1 and 4.5 °C for deep pools, and between -11.5 and -8.4 °C in the air. R^2 for thawing degree-days at lake-bottom and in the air ranged between 0.83 and 0.91 at shallow sites, and up to 0.85 for deep sites. Using the four warmest and coldest years as an analogue for climate change - an adjustment that may occur this century - talik geometry may take millennia to reach equilibrium.
These data are included in a proceedings paper under the same title and authors for the 2021 Regional Conference on Permafrost in Boulder, Colorado.