Caption: The heating effect of the Sun in the Northern Hemisphere for winter.

The diagram shows the winter solstice for the Northern Hemisphere.

Of course, it is summer in the Southern Hemisphere---where everyone is standing on their head.

Credit/Permission: © David Jeffery, 2003 / Own work.
Image link: Itself.
Local file: local link: season_004_winter.html.html.
File: Earth file: season_004_winter.html.html.