Abstract
We used a mechanistic physical model to examine the effect of variability in dissolved organic carbon (DOC) concentrations on the physical properties of small temperate lakes. The model was validated on eight small (6 × 10 −4 to 3.8 × 10 −2 km 2 ) lakes in Wisconsin and Michigan, with a standard error 2°C colder than the reduced scenario. We found a nonlinear relationship between DOC and temperature, with clearer (lower DOC) simulations being more sensitive to climate variability, suggesting that DOC may act as a buffer against a warming climate. Our model showed that DOC also influenced epilimnetic depths, as nocturnal mixing (related to the vertical partitioning of heat) was more important than wind‐driven mixing. Small lakes are globally important regulators of biogeochemical cycles and are structurally different from larger lakes. Important feedbacks to physical processes must be accounted for when understanding the effects of changing DOC and climate on small lakes.