("Ron Garret" wrote)

It is worth noting also that dark surfaces absorb and radiate more
readily than light ones, and so they get hotter during the day and
colder at night. Cirri are all painted white in order to take advantage
of this phenomenon and keep the skin from getting too hot in the sun.
(You'll never see a non-white Cirrus. It's part of the certification
conditions to paint the white.) Accordingly, Cirri are less prone to
radiation-induced cooling and icing than a dark-colored plane would be,
all else being equal.


I get the sun heating darker surfaces up (many degrees!) more than an
identical white surface.

What I don't get is: Two wings of identical design and an identical starting
temp, both sitting out on a cold February night (no sun). How does the dark
wing get colder than the white wing?

If it's a microscopic temperature difference because of star twinkle and
ambient light pollution from the surrounding city, I can see that. However,
a number of degrees between the white wing and the dark wing at night? Nope,
I still don't get it.


Montblack