Water-to-ice heat transfer in ice-covered water bodies

Despite the pivotal relevance of water-to-ice heat flux in ice-covered lakes to global ice mass loss, its quantification in natural systems remains a challenge. We previously built a conceptual framework to mimic ice-covered lakes, and found that they can host five thermal regimes as a consequence of the combined effects of non-monotonic equation of state of cold waters, solar radiation, and geothermal heating. These different regimes are adjacent to each other within the controlling parameter domain, and exhibit high sensitivity, especially to the bottom temperature. Moreover, the water-to-ice heat flux changes drastically across the regimes. We further leverage our conceptual framework to predict the thermal response of ice-covered lakes, performing direct numerical simulations. We construct heat transport scaling laws which allow a continuous representation of the heat flux across different thermal regimes.