Re: Re[3]: Tide Data

From: Ken Poulton (poulton@zonker.hpl.hp.com-DeleteThis)
Date: Wed Dec 14 1994 - 11:43:52 PST


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Date: Wed, 14 Dec 1994 11:43:52 -0800
From: Ken Poulton <poulton@zonker.hpl.hp.com-DeleteThis>
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To: wind_talk@opus.hpl.hp.com-DeleteThis
Subject: Re:  Re[3]: Tide Data


> What I would really like to know is a RULE OF THUMB which would allow
> me to figure out the percentage of full current as a function of time
> (relative to high/low tides).

It's site dependent. For the GG, the lag from high/low tide to slack
water is about two hours! For 3rd Ave, it's about an hour. I would
guess at Alviso (end of the Bay) it's zero. It so happens that
slack water occurs at about the same time at these three sites, but
that's more of a special case; it won't hold going up to Rio.

If you have a waveform for the tide level, then the first-order current
calculation is to take the derivative of that. But then you need to
add all those site corrections, and river-speed corrections (several
knots at Rio and GG in the spring, I believe).

> so we're renaming this list to
> "circuit-analogies-for-macro-hydrodymanics_talk_among-sailing-starved-ingunear-geeks"
> or somesuch?

Gotta do *something* to keep the mailing-list system from getting flabby...

Ken Poulton
poulton@opus.hpl.hp.com-DeleteThis

"I don't suffer from insanity. I enjoy every minute of it." -- A. Nony Mous



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