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Re: double tide cause



I wrote:

> You would expect the tides to be somewhat attenuated,
> because the Gulf is fairly small, and connected to
> the open ocean only by rather narrow straits.

Than at 10:41 AM 9/3/01 -0500, Paul O. Johnson wrote:

Fairly small? It's the fifth largest sea. See
http://www.infoplease.com/ipa/A0001773.html

No, it's not.

1) First of all, according to that reference, it's ninth... and only half a
percent bigger than #10.

2a) More importantly, nobody cares what it's ordinal rank is. What matters
is its size. The status of the preceding 6 contenders is
irrelevant. Suppose we filled in or chopped up those contenders, so that
the Gulf ranked third, behind the Pacific and Atlantic. It would still
have 50-fold less area and 5-fold less width than the Atlantic, which is
what most people (especially Floridians) would be comparing it to.

I stand by my assertion that the Gulf is fairly small. It's endogenous
tide-driving potential is reduced by a quite noticeable factor.

Fairly narrow straits? Both the Florida and Yucatan straits are 100 miles
wide, See
http://www.reliefweb.int/w/map.nsf/wByCLatest/37DD6CB1016FF5B9852569EA006B9C
B6?Opendocument

3a) If you count the part of the Strait of Florida that is deeper than 200
meters, it's a lot less than 100 miles wide.

The Yucatan Channel is wider, but it connects to the Caribbean, not the
open ocean.

3b) In any case, how much water do we expect to sluice through such straits
during the ~3 hours that the tide is changing?

I remain of the opinion that these straits cause the Gulf to be
sufficiently decoupled that there is no reason to expect the Gulf coast to
mimic the US Atlantic coast.

Observations are consistent with this notion:
http://www-ocean.tamu.edu/~wormuth/tides/globaltidalpatterns.gif

======================

Bottom line: The once-a-day tide-producing potential is only about 2x
smaller than the more-familiar twice-a-day tide-producing potential. The
Gulf appears to have a resonance that responds preferentially to the
once-a-day component.