Science Chap 3 questions
How does air pressure change as altitude increases?
Air pressure decreases as altitude increases. As air pressure decreases, density decreases.
What 2 instruments are commonly used to measure air pressure?
Aneroid barometer and Mercury barometer
How does heating air affect its density and pressure?
As the air gets warmer its density decreases and as density decreases air pressure decreases
Why do you feel cold in the thermosphere?
Because gas molecules in this layer move fast so the temperature is very high. But the molecules are spaced far apart in the thin air so there are not enough to collide with you and keep you warm
How does energy from the sun travel to the Earth?
Energy travels from the sun to the Earth as electromagnetic waves. Most of the energy travels in the form of visible light and infrared radiation. A small amount arrives as ultraviolet radiation
What causes global winds?
Global winds are caused by the unequal heating of Earth's surface and occur over a large area.
Stratosphere
Layer above the troposphere. Contains ozone layer and protects living things from ultraviolet rays. Upper layer of stratosphere is warmer than the lower layer .
Mesosphere
Middle layer of the atmosphere protects the Earth's surface from being hit by most meteoroids. air is very thin.
Exosphere
Outer layer
What happens to the sun's energy when it reaches Earth?
Some of the suns energy is absorbed or reflected by the atmosphere before it can reach the surface. Some wavelengths of radiation are absorbed by layers in the atmosphere. Clouds act as mirrors reflecting sunlight back into space. Particles and gases scatter light in all directions.
What is wind?
The movement of air from an area of high air pressure to an area of low pressure caused by unequal heating of the atmosphere.
What causes local winds?
The sun's energy heats Earth's surface during the day. The angle of the sun's rays cause temperature differences at Earth's surface.
How is wind related to air pressure and temperature?
Winds are caused by differences in air pressure. As temperature increases the air becomes less dense and its air pressure decreases. The less heated air will be cooler and denser. The cool dense air flows underneath the warm less dense air forcing the warm air to rise.
What units are used to measure air pressure?
inches of mercury or millibars 1 in.= 33.86 millibars
troposphere
inner or lowest layer of the Earth's atmosphere. the layer closest to the Earth.
Ionosphere
lowest layer of the the thermosphere
What is the composition of Earth's atmosphere?
nitrogen-78%, Oxygen-21%, other gases-1% such as carbon dioxide, water vapor, and other gases, as well as particles of liquids and solids
Thermosphere
outermost layer of the atmosphere Consists of two layers
What is the Most dense layer , where all mass of the atmosphere is concentrated.
troposphere
Name the four main layers of the atmosphere
troposphere, stratosphere, mesosphere, thermosphere