Heating of the earth exterior and atmosphere and influences patterns of precipitation the sun heats the air at the equator causing it to expand and rise. This warm moist air cools as it rises. Since cool air holds less water vapor than warm air the water carried by the rising air mass condenses and forms clouds which produce the heavy rain fall associated with the tropical environment. Eventually this equatorial air mass ceases to rise and spreads north and south. The high altitude air is dry since the moisture it once held fell as a tropical rain fall. When the air mass flows north and south it cools which increases its density. It sinks back to the earth’s surface at about 30 latitude and spreads north and south. The air draws moisture from the lands over which it flows and creates deserts in the process. Temperature is plotted on the left vertical axis and precipitation on the right vertical axis. Temperature and precipitation are potted on different scales so 10 C is equivalent to 20 mm of precipitation. Climate diagrams for wet areas such as tropical rain forest compress the precipitation scale for precipitation above 100mm so that 10C is equivalent to 200mm of precipitation. This will change in scale rainfall data from very wet climates can be fit on a graph of convenient size. The temperature and precipitation scales are constructed so that 10C equals 20mm of...

The circulation of air over the earth is largely due to the unequal heating of the surface. The global circulation of pressure and wind plays an integral role in the heat balance of the earth, as well as creating global ocean currents. The global circulation of the atmosphere transfers warm air from low latitudes towards high latitudes, and cold air from high latitudes towards low latitudes. This exchange keeps low latitude regions where there is a net gain of energy through the year from