Figure 24.
HOW AIR MOVES IN THE ATMOSPHERE AROUND THE GLOBE There are predictable ways that the atmosphere travels around the globe. Remember that the sun is stronger near the equator, so warm low pressure systems form. Near the top of the troposphere, some of the air moves northward while the other half moves southward. Of course, this air cools as it travels. Eventually sinks back down and gets sucked back toward the equator. You can see now that a circulatory pattern is set up. This circulatory pattern is a convection cell. Remember also that the earth rotates. This complicates the convection cell, so that the cooled air lands further to the right than it should. This is only because the earth has rotated. This leads to what we call the Coriolis effect. Figure 25 shows how this works:
49
