Physical and biogeochemical processes in ice-covered lakes

Ice-covered lakes are facing pervasive changes in their ice-cover periods. Global observations reveal the decline in annual ice-on duration while forecasts of numerical models preclude massive changes of these systems in the next decades as a result of global warming. Understanding the links between the under-ice physics and biogeochemical processes is critical for anticipating the evolution and fate of ice-covered lakes and their ecosystems.

The goal of this interdisciplinary research study is to:

  • characterise radiatively-driven convection and mixing in ice-covered waters
  • test high-resolution vertical in-situ observations and new autonomous under water vehicles and determine the horizontal structure of convective cells
  • investigate the effect of convective mixing on phytoplankton
  • investigate the accumulation and release of greenhouse gases
  • develop mechanical energy and heat balances of under-ice waters
  • investigate the role lateral flows in the thermal evolution of ice-covered waters.

Bouffard, D. G. Zdorovennova, S. Bogdanov, T. Efremova, S. Lavanchy, N. Palshin, A. Terzhevik, L. Råman Vinnå, S. Volkov, A. Wüest, R. Zdorovennov, H. N. Ulloa. Under-ice convection dynamics in a boreal lake. Inland Waters 9(2).

Winters, K.B., H.N. Ulloa, A. Wüest, and D. Bouffard (2019). Energetics of radiatively-heated ice-covered lakes. Geophysical Research Letters.

Ulloa, H.N., A. Wüest, and D. Bouffard (2018). Mechanical energy budget and mixing efficiency for a radiatively heated ice-covered waterbody. Journal of Fluid Mechanics 852: R1. doi:10.1017/jfm.2018.587.

Bouffard, D. and A. Wüest (2019). Convection in lakes. Annu. Rev. Fluid Mech. 51: 189 – 215. Doi: 10.1146/annurev-fluid-010518-040506.

Bouffard D., R.E. Zdorovennov, G.E. Zdorovennova, N. Pasche, A. Wüest and A.Y. Terzhevik (2016). Ice-covered Lake Onega: effects of radiation on convection and internal waves. EUROPEAN LARGE LAKES IV, Hydrobiologia 780: 21–36, doi: 10.1007/s10750-016-2915-3.

Natacha Pasche, Hilmar Hofmann, Damien Bouffard, Carsten J. Schubert, Petr A. Lozovik & Sebastian Sobek (2019): Implications of river intrusion and convective mixing on the spatial and temporal variability of under-ice CO2 , Inland Waters 9(2).  DOI: 10.1080/20442041.2019.1568073.