Studies on water movements and sediments in Southern Lake Michigan : part 1[-3] ... / by John C. Ayers.

A reference level at 60 decibars was chosen as giving a minimum
interference from the bottom.
At the ends of each section, where the bottom was at less
than 60 meters, substitution was made from the lower part of the
nearest full-depth station according to the method of HellandHansen (1934).
Lake Michigan winds at each of the synoptic hours were obtained either 1) from microfilmed copies of ships' weather logs
obtained from the National Weather Records Center in Asheville,
North Carolina, or 2) from teletype reports transmitted by selected Weather Bureau stations near the lake and received at the
station at Willow Run Airport.
Mean ships' winds for each sector (west and east, using the
87th meridian as the dividing line) were obtained and entered as
the wind for that sector, whenever ships' observations were
available. On some occasions ship observations along the 87th
meridian were used as the winds of both sectors.
At times when no ships' observations were available, Weather
Bureau observations on land were utilized in the following
manner:
In the west sector, the vector mean wind of the following
stations was used: Milwaukee (MKE), Glenview, Illinois, (NBU),
Joliet (JOT), Midway Airport, Chicago (MDW), O'Hare International
Airport, Chicago (ORD), andMeigs Field, Chicago (CGX).
In the east sector, the vector mean wind of the following
stations was used:.Gra4d, Rapids (GRR), Kalamazoo (AZO),
Muskegon (MKG), and Nout Pend (SBN).

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