Winter operations, 1970-1971 / John C. Ayers, Norbert W. O'Hara, William L. Yocum.

plume-direction components. Reading from the graph of wind frequencies:
Direction decade 240~ Wind frequency 2.5% of time
250~ 3.5%
260~ 3.0%
270~ 4.2%
280~ 5.5%
290~ 3.0%
300~ 3.0%
310~ 5.0%
320~ 3.5%
330~ 3.0%
Total 36.2% of time
Thus, about a third of the winter winds blow from directions that could produce significant onshore components of plume direction. Some of these winds will
be weak, and not productive of significant onshore components of plume direction;
some will be strong.
All of the wind-induced onshore components of plume direction will add vectorially to the plume-direction component of the alongshore current, which will
vary in strength.
During about two-thirds of the winter the plant's thermal plume will move
alongshore or offshore.
In our experience, the natural forces of ice-building and ice-destruction
are always present during the winter; one or the other dominates as appropriate
conditions develop. During the two-thirds of the winter when the Cook Plant
plume will not have significant contact with the shore ice, these natural forces
will be in control. During that third of the winter when the Cook Plant plume
could reach the shore ice these natural forces will continue to be operative on
every part of the shore ice that the plant's thermal plume is not reaching at
that time.
The Cook Plant thermal plume appears, at this time, to be an ice-destructive
force potentially operative about a third of the time in winter. During this time
it will be a destructive force wandering randomly along the shore, and staying in

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