1. Weather Terms/ Tools
Meteorology
Meteorologist
Forecast
Mass
Temperature
Humidity
Air Pressure
The study of weather
A person who studies weather
A prediction about what kind of weather to expect
The amount of matter in an object
The average amount of energy of motion of each particle of a substance
The amount of water vapor in the air
The force of air pushing on an object

2. Weather Terms/ Tools
Visibility
Dew Point
Thermometer
Hygrometer
Barometer
Anemometer
Wind vane
The distance one can see through the air
The temperature at which air has to be for water vapor to condense into a water droplet
Measures temperature in degrees Celsius
Measures humidity as a percentage (%)
Measures air pressure in millibars (mb)
Measures wind speed in km/hr (1 km = 0.62 miles)
Measures wind direction (N, S, E, W)

3. Layers of the Atmosphere
Troposphere
Stratosphere
The lowest layer (closest to Earth) is the troposphere.
Contains most of the mass of the atmosphere
Earth’s weather happens in the troposphere.
The depth varies from 16 km above the equator to less than 9 km above the poles
As altitude increases, temperature decreases
Where people live
Layer above the troposphere.
From the top of the Troposphere to 50 km above Earth’s surface (2nd layer)
The “ozone” layer is in the stratosphere.
As altitude increases, temperature increases because the ozone layer absorbs heat

4. Layers of the Atmosphere
Mesosphere
Thermosphere
Above the stratosphere (3rd layer)
Between km above Earth’s surface.
Where meteors burn up to create shooting stars.
As altitude increases, temperature decreases to about -90°C
Outermost layer of the atmosphere.
Extends from 80 km into space.
“Thermo” means heat- air is up to 1800 C since it is the closest to the sun- air is so thin it still would feel cold
Comprised of two separate sub-layers: Ionosphere, Exosphere

5. Composition of the Atmosphere
Gases in the atmosphere
Ozone Layer
Aurora Borealis
Found in Stratosphere
Ozone- form of oxygen (O3- three O molecules)
Absorbs UV light from the Sun
Also called Northern or Southern Lights
Occur in Ionosphere
Oxygen or Nitrogen gaining an electron

6. The average amount of energy of motion of each particle of a substance
Heat Transfer
Temperature
Thermal Energy
Heat
Heat transfer
The average amount of energy of motion of each particle of a substance
The total energy of motion in the particles of a substance
The transfer of thermal energy from a hotter substance to a cooler one
Three ways heat is transferred: conduction, radiation, convection

7. Heat Transfer
Conduction
Radiation
Conduction: Energy transfer between molecules as a result of contact (touching).
Radiation: Energy that travels as waves through space between objects and materials.
Differential heating: Different materials heating at different rates (cement, dirt, water)

8. Convection Density Density equation
Heat Transfer
Convection
Density
Density equation
Convection: The transfer of energy (by currents) from one place to another in a gas or liquid.
Density: A ratio between the mass of a liquid/object and its volume. Measured in (g/ mL)
Equation:
Example:
Density =
Mass
Volume
Density = D=
M (g)
V (mL) =
50 g
45 mL
1.11 g/mL

9. Heating the Troposphere
Heat Transfer
Convection currents
Heating the Troposphere
The upward movement of warm air and the downward movement of cool air
Radiation, conduction, convection help to heat the troposphere
Troposphere is mostly heated by convection
- Heated air is cycled by convection currents

10. Water in the Atmosphere (Water cycle)
Evaporation
Water vapor
Humidity
Relative humidity
The movement of water between the atmosphere and Earth’s surface
The process by which water molecules in liquid water escape into the air as water vapor
Water in the form of a gas
A measure of the amount of water vapor in the air
The percentage of water vapor that is actually in the air compared to the maximum amount of water vapor the air can hold at a particular temperature. Warm air can hold more water vapor than cool air.

11. Water in the Atmosphere (Water cycle)
Condensation
Dew point
Cirrus
Cumulus
Stratus
Alto-
Nimbo-/-nimbus
Cumulonimbus
Molecules of water vapor in the air become liquid water- how clouds are formed
The temperature at which condensation begins
Wispy, feathery clouds made of ice crystals
Look like fluffy, rounded piles of cotton
Clouds that form in flat layers
Means “high”; between 2 and 6 km
Means “rain”
Often produces thunderstorms

12. Water in the Atmosphere (Water cycle)
Fog
Precipitation
Types:
Rain
Sleet
Freezing rain
Snow
Hail
Clouds that form at or near the ground
Any form of water that falls from clouds and reaches Earth’s surface
Drops of water that are at least 0.5 mm in diameter
Ice particles smaller than 5 mm in diameter
Freeze when they touch a cold surface
Ice crystals called snowflakes that are six-sided
Round pellets of ice larger than 5 mm in diameter

13. Surface Water (Rivers and Lakes)
Tributaries
Watershed
Divide
Reservoir
Nutrients
eutrophication
The streams and smaller rivers that feed intoa main river
The land area that supplies water to a river system
A ridge of land that seperates one watershed from another
A lake that stores water for human use
Substances such as nitrogen and phosphorus that enable plants and algae to grow
Over many years, the nutrients build up in the lake in a process called eutrophication