Currents and Temperatures in Green Bay,Lake Michigan

Current velocities and water temperatures were measured in the four main passages between Green Bay and Lake Michigan and at several sites within the bay during summer and fall 1977. Monthly resultant currents indicate there is anticlockwise circulation in the bay during dominant southwesterly wind and a reversal of this pattern during episodes of northeasterly wind. It is common for two layers to flow through the mouth of the bay in opposite directions during the stratified season. Cold hypolimnetic lake water entering through the mouth and extending far into the bay maintains stratification and promotes flushing. The effects of resonance of forced and free long wave disturbances are prominent in current records; these oscillations are coherent and in phase across the mouth.