An array of 15 moorings, supporting current meters at 15 and 50 m depth, was in place in Lake Michigan from June 1982 to July 1983. Six moorings surrounded the southern basin on about the 75 m&bath, six closely spaced moorings transected the mid-lake ridge and adjacent valley, and three moorings occupied the centers of the southern and northern basins. In the southern basin, monthly-averaged currents are weakly anticyclonic during June and July, cyclonic during the rest of the year, and most intense during March. Temperatures and bidaily-averaged currents both show the effects of the gravest (4-day period) vortex-mode oscillation. Also, it is shown that the seasonal thermocline became well established much earlier in 1983 (early June) than in 1982 (middle August).

Office of Oceanic and Atmospheric Research (OAR)

Michigan, Lake