Atmosphere and Air Flashcards
Atmospheric Composition
- Nitrogen - 78%
- Oxygen - 21%
- Argon - .93%
- Carbon Dioxide - .03%
- Water Vapor
- Trace gases
Oxygen:
- Gas
- Living things breathe oxygen in order to break down food for energy.
Carbon Dioxide:
- Gas
- Has a minor role in regulating the amount of energy the atmosphere absorbs AND acts as a plant fertilizer
Ozone:
- Gas
- Absorbs ultraviolet radiation from the sun.
Water Vapor:
- Gas
- Has a major role in regulating the amount of energy the atmosphere absorbs AND is the source of clouds, rain, and snow.
Dust and Salt:
- Solid
- Provide a solid surface for water vapor to condense around so that clouds can form.
Layers of the Atmosphere:
- Troposphere
- Stratosphere
- Mesosphere
- Thermosphere
- Exosphere
Troposphere:
- 0-11 kilometers
- Highest Air Pressure
- Contains most of the gases of the atmosphere
- Weather, Life forms, and Jets
- Colder as altitude increase
Stratosphere:
- 11-48 kilometers (!)
- Molecular heat rises due to Ozone absorbing heat
- Ozone Layer, Weather balloons
- Hotter as altitude increase
Mesosphere:
- 48-95 kilometers (!)
- Molecular heat falls because there’s not a whole lot here! (coldest layer)
- Meteors (shooting stars) burn here
- Colder as altitude increase
Thermosphere:
- 95-500 kilometers (!)
- Molecular heat rises
- Ionosphere, Auroras
- International Space Station
- Hotter as altitude increase
Exosphere:
- Above 600 kilometers (!)
- Outermost layer (Space!)
- Some Hydrogen(H) and Helium(He)
- Satellites
Temperature
The measurement of how rapidly or slowly molecules move around.
Heat
The transfer of energy that occurs because of a difference in temperature between substances.
- Conduction (When molecules collide; touching)
- Convection (through flow of a heated substance)
- Radiation (through space or electromagnetic waves)
Fahrenheit:
- Boiling point: 212°
- Freezing point: 32°
- Absolute zero: -523° (When molecules are not moving AT ALL).
Celsius:
- Boiling point: 100°
- Freezing point: 0°
- Absolute zero: -273°
Kelvin:
- Boiling point: 373°
- Freezing point: 273°
- Absolute zero: 0°
- There are no negative numbers on the Kelvin Scale!
Absolute Zero
The temperature at which molecular motion theoretically stops! This does not occur anyplace in the universe.
Dew Point
The temperature to which air must be cooled at constant pressure to reach saturation.
- Dew is formed
- The higher the dew point, the more uncomfortable and humid the air
Condensation
The process of water vapor changing into liquid water. It plays a role in creating rain when water vapor in the atmosphere becomes water droplets.
Density:
- Mass per volume
- As altitude increases (moving up through Earth’s atmosphere), the density of the air decreases.
Air Pressure:
- The force exerted by the molecules of the atmosphere as they are pulled toward Earth’s center.
- As altitude increases, air pressure decreases.
- Air at the bottom of the atmosphere (The troposphere) has higher density and pressure.
Wind:
- Created by the unequal heating of the Earth
- Moves from areas of high air pressure to areas of low air pressure.
Humidity
The amount of water air can hold at a given temperature. This is a constant!
Relative Humidity
The amount of water the air is actually holding compared to how much it can hold.
Temperature Inversion
- When upper layers of the troposphere are warmer than the lower layers.
- The warmer layer is above the colder layer.
- On a cold, clear, winter night Earth’s surface cools rapidly and becomes colder than the air above it resulting in upper layer of the troposphere being warmer!
Cloud Formation:
- Convection Currents
- Warm air rising over mountains (Orographic Lifting)
- Air masses of different temperatures meet
Types include…
- Cirro- (High)
- Alto- (Middle)
- Strato- (Low)
The Water Cycle:
- Evaporation (Water on Earth’s surface turn into water vapor)
- Condensation (Water vapor in clouds turn to liquid
- Precipitation (Rain, snow, sleet, or hail falls to Earth’s surface).
