Robert G. Fovall

Building on your understanding of how the ocean affects weather, turn your attention to the tropical cyclone, generally known as the hurricane or typhoon. Examine the typical structures of the tropical cyclone, and investigate the conditions needed to unleash these dangerous storms.

Why does dew form on some mornings? Why does it take longer to cook food at higher elevations? Discover the answer to these questions as you learn about saturation: the point where air holds the highest amount of water vapor that it can contain.

What is air made of? Is it always true that hot air rises and cold air sinks? Learn more about the air that surrounds us and cushions us from the outer reaches of space, and examine the various layers that make up the earth's atmosphere.

After mastering the four forces that affect wind, step back to view their patterns of flow across the Earth's hemispheres. Examine the two models of air circulation that help account for large-scale air-circulation patterns and variations in temperature from the poles to the equator.

Add a new element to your understanding of the atmosphere—water—and learn some basic facts about air's capacity to hold water vapor, including the impact of temperature on atmospheric moisture and the implications for weather.

One of the most familiar and beautiful features of weather is the cloud. In this episode, examine different kinds of clouds, learn how clouds are born, why and how they take their distinctive shapes, and what kinds of conditions are likely to produce clouds.

If all the Earth receives energy from the sun, why are there such wide temperature differences across the planet? Why do we have seasons? Answer these questions while learning about how heat moves through the atmosphere via two basic processes: conduction and convection.

In this episode, you encounter some of the most dramatic air-flow patterns found in nature: the swift, turning winds of the cyclone. Trace the lifecycle of the extratropical cyclone, which draws its power from the huge energy generated when different air masses meet.

From thunderstorms to typhoons to driving winds, the world's weather is often tumultuous, destructive, and surprising. And yet, all these phenomena represent Nature's attempt to mitigate extreme conditions. In this introduction, begin to explore some of these extremes as you examine the great complexity of the world weather system.

In addition to pressure differences and the Earth's rotational movement, two other forces help to determine the winds' strength and direction: friction and centripetal force. Learn about these two forces and examine how they shape the winds the world over.