Another complication of the wind patterns is the tilt of the earth and the seasons.
As the earth's tilt moves around the sun, different regions are pointed towards
the sun (more about this in an upcoming unit!).
So, on the equinoxes (March and September), the sun shines most directly on the
Equator. In December, it shines most directly 23oS, and in June it
shines most directly on 23oN.
The effect this has on where the Equatorial High/ITCZ is located lags about
one month behind. The animation above models this shift.
Other causes for complications:
There many other reasons why the wind patterns aren't as simple as this. Just a
couple of these are:
Since land heats faster than water, land produces more rising
air than so seas.
Since the southern hemisphere has more water surface than the northern,
the northern hemisphere receives more "imbalanced" heating than the southern
hemisphere.
