Bathymetry and latitude modify lake warming under ice Ramón Casañas, Cintia Luz Ulloa, Hugo N. Doda, Tomy Winters, Kraig B. Bouffard, Damien In late winter, solar radiation is the main driver of water motion in ice-covered lakes. The resulting circulation and mixing determine the spatial distribution of heat within the lake and affect the heat budget of the ice cover. Although under-ice lake warming is often modeled as a one-dimensional (1D) vertical process, lake bathymetry induces a relative excess heating of shallow waters, creating horizontal density gradients. This study shows that the dynamic response to these gradients depends sensitively on lake size and latitude – Earth's rotation – and is controlled by the Rossby number. In the ageostrophic limit, horizontal density gradients drive cross-shore circulation that transports excess heat to the lake interior, accelerating the under-ice warming there. In the geostrophic regime, the circulation of the near- and off-shore waters decouples, and excess heat is retained in the shallows. The flow regime controls the fate of this excess heat and its contribution to water-induced ice melt. 2026-02-16T09:47:37Z 2026-02-16T09:47:37Z 2021 journal article Ramón, C. L., Ulloa, H. N., Doda, T., Winters, K. B., and Bouffard, D. (2021). Bathymetry and latitude modify lake warming under ice, Hydrol. Earth Syst. Sci., 25, 1813–1825, https://doi.org/10.5194/hess-25-1813-2021. https://hdl.handle.net/10481/111022 https://doi.org/10.5194/hess-25-1813-2021 eng http://creativecommons.org/licenses/by-nc-nd/4.0/ open access Attribution-NonCommercial-NoDerivatives 4.0 Internacional EGU