BIO201H5 Chapter 4: 4
perpendicular to the surface when the sun is directly overhead at
noon
o Move toward higher latitudes (toward poles), photon flux density
drops
• Differential heating of earth surface is translated by conduction heat
from surface of earth to atmosphere above i
• Equator is tiled 23.5o with respect to the path of the earth follows in its
orbit around the sun
o Therefore Northern Hemisphere receives more solar energy than
the Southern Hemisphere during the Northern summer and less
during winter
