Summer thermal structure and anticyclonic circulation of Lake Erie

In most thermally stratified lakes, the summer thermocline has the shape of a dome, with a shallower depth offshore than nearshore. This configuration is accompanied by a lake-wide cyclonic circulation. Lake-wide observations of subsurface temperature in central Lake Erie revealed an atypical depressed or bowl-shaped thermocline in late summer, with a deeper thermocline in the middle of the lake and a shallower thermocline nearshore. Currents measured in the central basin when the bowl-shaped thermocline was observed were anticyclonic, forming a single basin-wide gyre. It is suggested that the unusual bowl-shaped thermocline is the result of Ekman pumping driven by anticyclonic vorticity in surface winds. The bowl-shaped thermocline can lead to greater hypoxia in bottom waters and negative effects on biota by reducing the hypolimnetic volume. Citation: Beletsky, D., N. Hawley, Y. R. Rao, H. A. Vanderploeg, R. Beletsky, D. J. Schwab, and S. A. Ruberg (2012), Summer thermal structure and anticyclonic circulation of Lake Erie, Geophys. Res. Lett., 39, L06605, doi:10.1029/2012GL051002.