The energy of sunlight causes most evaporation, sublimation, and melting. Energy is needed to evaporate the water and to move the water vapor by winds. This energy originally comes from the sun. 4/12/2021 8
the atmosphere. Like other matter, air has mass and takes up space. Air is made up of a mixture of invisible gases. ¾ of the earth’s atmosphere is nitrogen. Most of the rest is oxygen, but a small amount is carbon dioxide. The part of the atmosphere closest to Earth’s surface contains water vapor. The amount of water vapor depends on time and place. Air over the ocean or forest has more water vapor than air over the desert. Gravity pulls the mass of air in the atmosphere towards Earth’s surface. The pushing force of the atmosphere is called barometric pressure. Air pushes with equal force in all directions. Air pressure decreases as you go higher in the atmosphere. Barometer- an instrument that shows air pressure. 4/12/2021 11
blown many times, water continues to freeze on it, causing it to become too heavy for the winds to carry it back up. The frozen precipitation that forms is called hail. Study pg. 61 4/12/2021 18
high-altitude clouds that are thin, wispy, and white. 2. Cumulonimbus- Clouds that grow vertically and have rising air inside them. Vertical clouds can cause thunderstorms. 4/12/2021 19