Deep lakes like Lake Geneva release methane, a powerful greenhouse gas, and our new study shows that swirling currents inside the lake help spread it around. Using underwater sensors and simulations that track how water moves, we found that methane coming in from the Rhône River gets caught up in these currents and carried well beyond where it entered. The takeaway: to really understand how much methane a lake is emitting, you need to account for how water circulates inside it, not just where the gas is produced. A beautiful group work.
Khatun, S., Grilli, R., Rahaghi, A.I., Doda, T., Bouffard, D., Schubert, C.J., Chappellaz, J. and Perga, M.-E. (2026), Tracing the origins of metalimnetic methane in a stratified large lake: Insights from high-resolution mapping and three-dimensional hydrodynamic modeling. Limnol. Oceanogr. Lett, 11: e70158. https://doi.org/10.1002/lol2.70158