Methane emissions from lakes play a significant role in global fluxes and are essential to understanding climate sensitivity and feedback. However, uncertainties in quantifying this contribution still persist. Complex interactions between lake hypsography, climate, and biogeochemistry largely govern methane emissions from lakes. These interactions make it difficult to predict even at the individual lake scale due to the strong nonlinear nature of these relationships. Furthermore, well established understanding at individual lake scales does not necessarily translate similarly at Earth System scales asdrivers that control ecological variation in lakes are different from local to continental scales. We use coupled climate and dynamic process-based models, along with lake hypsography, to overcome this hurdle. The models describe lake physics and basic biogeochemistry, and allow us to resolve daily and yearly methane diffusive and ebullitive emission fluxes encompassing baseline, average and maximum range conditions in millions of lakes worldwide. Our analysis involved the examination of methane emissions and its apparent temperature sensitivity, using spatial and temporal aggregation, globaly and across key climatic zones. Our approach reveals relationships and patterns that may not be apparent from statistical analysis alone and helps address fundamental questions on the role of lakes and sensitivity to climate at Earth System scales.

Primary Presenter: Cristian Gudasz, Umeå University (cristian.gudasz@umu.se)

Authors:

Cristian Gudasz, Umeå University  (cristian.gudasz@umu.se)

Dominic Vachon, Université du Québec à Montréal, Montréal  (domvachon@gmail.com)

Yves Prairie, Université du Québec à Montréal, Montréal  (prairie.yves@uqam.ca)