IVP wrote:
> 89.8 [Mar 19], 66.8 [Jun 20], 90.0 [Sep 23], 66.9 [Dec 21] and day
> length [sunrise - sunset] of 12 hours and a few minutes

Yes, but that neglects to mention the polarity of the declination.  Quito
being nearly on the equator, the sun should be at 90 deg at each equinox,
which is what they are showing.  However, it's going to be 66.8 north in
June and 66.9 south in December, for a total swing of 46.3 according to
those numbers.

>> For example, I'm at about 42.5N so the height of the midday sun
>> varies from 42.5 + 23.5 =3D 66 deg at the summer solstice, to 42.4
>> deg at each equinox, to 42.5 - 23.5 =3D 19 deg at the winter solstice
>
> In Boston, according to
>
>
http://www.timeanddate.com/worldclock/astronomy.html?n=3D43&month=3D3&year=
=3D2010&obj=3Dsun&afl=3D-1&day=3D1
>
> 24.3 [Dec 21] to 71.1 [Jun 20] =3D 46.8 difference

Boston is about south from me, but close enough.  I don't know why they
think the sun is 4 deg higher there than what I came up with for here.  Som=
e
charts consider the angle to be to the bottom of the sun's disk as seen fro=
m
the ground because that's how it was measured with a sextant long ago.
However if they were using the bottom instead of the center their numbers
would be lower.  The figures you quoted make more sense for Washinton DC to
me than Boston.  I can't explain the discrepancy.

In any case, the spread is still about 47 deg, which is twice the tilt of
the earth's axis.


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