Temperature

Temperature is the measurement of the amount of heat energy a substance has. The more heat energy it has, the higher the temperature. The less heat energy a substance has, the lower the temperature. We know that Warm air rises because it has more energy and the particles separate, making the air mass less dense. We know that cold air sinks, because it has less energy, making the particles clump together, making the air more dense.

Pressure

Air pressure is caused by the weight of air. Air is more compressed(dense ) at sea level, creating higher air pressure. As the altitude gets higher, air pressure decreases.

Air Pressure and Weather:

Air pressure helps create changes in weather. Clouds form as a direct result of air pressure. Clouds will form under low pressure conditions. Air pressure also causes air to move, and aids in the creation of wind. Air will flow from high pressure to low pressure areas.

Cloud Formation

The water cycle consists of several steps: Evaporation/transpiration, condensation, precipitation and surface runoff.