LISS.398A TECHNOLOGY, ENVIRONMENT and HUMAN ADAPTATION:
PART I EARLY PEOPLES in
the NEW WORLD
CONVECTION CELLS
Latitudinal surface temperature differences cause warmer air
at the equator to rise. Cooler air moves equatorward from
the poles to replace it. As it rises, it moves poleward
cools and begins to drop. The earth's rotation causes this
circulation to take the form of three cells (as shown in
Fig. 1.1.1)
rather than just one. A fully
adequate, mechanical explanation of this phenomenon does
not appear to be available.
FRONTS
At the earth's surface cellular boundaries are sometimes
identified with surface fronts separating air of different
temperatures. The polar front (60o) separates cold
arctic air moving equatorward from warmer subtropical a
moving poleward. The 30o cellular boundary boundary
lacks such a frontal character at the surface. The
convergence of trade winds at the equator is termed the
intertropical convergence.
These cell boundaries move north-south seasonally and may be
subject to long term north south movements as well.
Colorado School of Mines
Division of Liberal Arts and International Studies
Dr. Joseph D. Sneed
jsneed@mines.edu
