|If the statement "Heat Rises" is true...then, why
is the north colder than the south?|
|Question Date: 2016-01-18|
The statement "heat rises" is a very true
statement, but when we say this we should think
about ."which direction is "up"? Do we mean up
away from the ground, or up north?
It turns out that heat rises in both of these
Heat rises due to density. Warm air is
less dense (less heavy) than cold air. The cold
air sinks and the 'lighter' warm air rises.
When we say "up" towards the sky, this statement
is true in the same way that a helium balloon
rises up into the sky. Helium is less dense than
regular air, so it rises up to the sky. Warm air
is also less dense so it also rises up into the
Let's look at how heat rises north.
The equator gets more sunshine and warmth from the
sun. As you move away from the equator the sun
rays aren't as strong, so as you move from the
equator to the poles the temperatures get colder.
So we can say that the warm air at the equator is
lighter than the cold air at the poles. And in
fact, air warm masses from the equator do move to
the poles to mix with the cold air there.
"Up" means two different things in your question.
When we talk about north and south, "up" means
"towards the north pole." But when we say that
heat rises, "up" here means "away from the
Heat rises away from the ground anywhere on the
planet: heat still rises away from the ground on
the North Pole.
North is not up and south is not down. We draw
maps that way, but only because it makes maps
easier to read. In the past we drew maps so that
east was up and west was down.
It's colder in the north because the angle formed
between the ground and the sun's rays is smaller
in the north than in the south. You can test
this by holding a sheet of paper out in the day
and seeing how the paper reflects less light as
you tilt its edge closer and closer to that of the
sun. South of the equator, it gets colder as you
go further south, for the same reason. This is
because the Earth is a ball, and not a sheet of
paper, and the equator is where the Earth's
surface is perpendicular to that of the sun's
Click Here to return to the search form.
Copyright © 2017 The Regents of the University of California,
All Rights Reserved.