Re: Tide article

[John Mallinckrodt <ajmallinckro@CSUPOMONA.EDU>]

On Sat, 20 Oct 2001, Jim Green wrote:

> John, that is interesting because as one gets closer to Alaskan waters  the
> tides don't act "normally" ie the same as on the West Coast -- as if the

> West Coast were normal.   A high water prediction variation of +- ~2hr
> doesn't surprise me.  But the much better synchronization of the Spring
> Tide/Neap Tide is unusual as far as I know.  I would be interested to know
> what the synchronization is over several months ---
>
> The tide races North along the West Coast and slows down near Puget Sound
> and then creeps across  the Alaskan Shore.  Besides this the tides may
> resonate very differently in the Sound.  Interesting.

Our tide clock was purchased in Los Angeles; it was not made "for"
any particular location.  Indeed, as I pointed out, the hand
completes two cycles each "mean lunar day" which is not a function
of location.  Also as I mentioned, the clock keeps excellent *long
term* track of the tides.  To expand on what I said before, there
are seasonal as well as biweekly variations that drive the tidal
extremes temporarily away from the specific times predicted by the
clock.  But if the clock is, for instance, set to properly predict
spring tides in July, it will be found to properly predict spring
tides *every* July for years on end (as long as the timing
mechanism functions properly and the batteries don't die.)

John Mallinckrodt      mailto:ajm@csupomona.edu
Cal Poly Pomona          http://www.csupomona.edu/~ajm