🚀 go-pugleaf

>The sun produces a second set of tides.  When the sun and moon line up
>(new moon or full moon) the effects are additive and called spring
>tides.  When they are at right angles to each other you can have two high
>and two low tides each day with the moons tide be the larger.

In general there are ALWAYS two high tides and two low tides each
day because of the two bulges produced by THE tidal effect.  The
effect of the sun is generally only to enhance or mitigate the
primary effect of the moon, and not to produce a second set of
bulges which would, if actually present, produce four high tides
and four low tides each day.

Notwithstanding the above--which is the whole story only in the
nonexistent ideal case--if you look at tide tables, you'll find
just about every variation imaginable.  It is, in fact, not at all
uncommon to have only one high tide and one low tide in a day.
This is what tends to happen near the first and third quarters
when the sun and the moon are at loggerheads.

John

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  John Mallinckrodt         email:  ajmallinckro@csupomona.edu
  Physics Department        Voice:  909-869-4054
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