Cook Plant preoperational studies, 1969 / John C. Ayers ... [et al.].

THERMAL PLUME STUDIES

Michigan City, Indiana, Higher Wind
On 26 June 1969 the R/V MYSIS arrived in Michigan City during the beginning
of a major blow from the southwest. Increasing strong southwest winds had blown
for several hours before our arrival at Michigan City. During the time we had
available to investigate the plume of the Michigan City Generating Station,
wind speed was 37-40 mph. Although we were unfamiliar with the area and had
problems in fighting the direct push of wind on the ship's hull and superstructure
the situation was favorable for a survey of the generating plant's plume under
higher wind conditions. Because the southwest wind was offshore, there was so
little fetch that wave action was small. We believe that Michigan City, on tiis
day, gave us an almost pure measure of the effect of wind ventilation alone on
the dimensions of the warm-water plume from the Michigan Citv plant.
A thermistor, trailing from the ship's 10-foot long bowsprit in the surface
water just ahead of the ship's bow wave, was the day's primary exploration
instrument.
The surface temperature conditions, so far as we were able to survev them
in the daylight remaining and under the difficult ship-handling conditions, are
presented in Figure 1. In one position in nine feet of water we were able, bv
steaming into the wind, to get a chain of thermistors (cross-calibrated against
the bowsprit thermistor) to descend vertically for sufficient time to obtain a
vertical temperature profile. This was tried at other positions along the breakwalls, but the combination of windage on the ship and water-currents off the
breakwalls prevented our obtaining vertical lowerings of the thermistor chain.
Intake (whose location we did not then know) and outfall (which we could not
reach) water temperatures for this day were kindly provided by Mr. E. L. Mann,
Manager of Plant Engineering of the Michigan City plant, to whom our formal

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