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Abstract Since 2005, investigators at the University of Minnesota, Duluth's Large Lakes Observatory have been maintaining subsurface moorings and surface buoys in Lake Superior to study thermal structure and currents throughout the water column and throughout the year. A single site has been continuously occupied for over 17 years as of the writing of this manuscript, another 10 sites have been occupied for multiple years, and for 3 months in summer 2017 an intensive field campaign occupied 12 sites simultaneously in western Lake Superior. All of these data are available on a publicly accessible archival site hosted by the University of Minnesota. 

Abstract Observations of radiatively driven convection in deep, ice‐free Lake Superior from a set of moorings and an autonomous glider are used to characterize the spatial and temporal scales of the phenomenon. The moored observations show that instability builds at the surface on scales of hours, water near the bottom of the lake begins warming roughly 6 h after sunup, and the water column homogenizes a few hours after sundown. Glider observations suggest the existence of distinct convective chimneys, which carry warmed water to depth with horizontal scales on the order of tens of meters. Patches of photoquenched phytoplankton coincide with patches of anomalously warm water, providing a secondary tracer of water recently in the euphotic zone, and provide insight into the vertical development of convective chimneys. An analysis of the abundance of convective chimneys is used to estimate the lateral scale of convective cells, which appears to be on the order of 50 m.