ABSTRACT
This chapter focuses on the effects of changing mixed layer depths on the light environment for photosynthesis and other irradiance-dependent processes in both the ocean and lakes. It describes the major drivers of mixed layer depth in pelagic environments and how they are heterogeneously impacted by climate change. The chapter examines trends in mixed layer depth and light climate using time series measurements of temperature and attenuation spanning two decades or more and compare those to model predictions. It considers the implications of these findings on future investigations of climate change effects on aquatic ecosystems. Better appreciation of the effects of climate change will derive from both more intensive environmental observations of what is changing as well as more sophisticated models to provide robust predictions of future change. This has been the general trend in predicting climate change overall and is specifically the case for questions about climate change effects on mixed layer irradiance.
