1. Earth’s Weather
Weather Terms

2. Water Cycle CONDENSATION PRECIPITATION EVAPORATION COLLECTION
Water gets into the
atmosphere by:
PRECIPITATION
EVAPORATION
About one-third of the solar energy reaching the Earth is used in evaporating water. About 380,000 cubic km/95,000 cubic mi is evaporated each year. The entire contents of the oceans would take about one million years to pass through the water cycle. (Image © Research Machines plc) Natural circulation of water through the upper part of the Earth. It is a complex system involving a number of physical and chemical processes (such as evaporation, precipitation, and infiltration) and stores (such as rivers, oceans, and soil).
Water is lost from the Earth’s surface to the atmosphere by evaporation caused by the Sun’s heat on the surface of lakes, rivers, and oceans, and through the transpiration of plants. This atmospheric water is carried by the air moving across the Earth, and condenses as the air cools to form clouds, which in turn deposit moisture on the land and sea as precipitation. The water that collects on land flows to the ocean overland – as streams, rivers, and glaciers – or through the soil (infiltration) and rock (groundwater). The boundary that marks the upper limit of groundwater is called the water table.
The oceans, which cover around 70% of the Earth’s surface, are the source of most of the moisture in the atmosphere.
COLLECTION
Water Cycle
TRANSPIRATION

3. transpiration and evaporation
Water Cycle
Precipitation
Collection
Run-off
Groundwater
Evapotranspiration
Evaporation
Transpiration
Condensation
Collection
Water gets into the atmosphere by:
transpiration and evaporation

4. Water Cycle
collection

5. Temperature A measure of how fast air molecules are moving
HIGH – molecules moving molecules moving rapidly
LOW – molecules moving slowly
SCALE
Freezing
Point
Boiling Point
Fahrenheit
32
212
Celsius 0
100
Kelvin
273
373

6. Temperature Scales

7. Measurement of Water Vapor
Humidity - the amount of water vapor in the air
Temperature affects how much moisture is in the air
Warmer air can hold MORE moisture – molecules are farther apart creating more space for the water molecules to fit in
Dew point – The temperature at which water vapor will condense
Relative Humidity – the amount of water vapor present compared to the amount that could be held at a specific temperature

8. AIR PRESSURE Weight of air column
Warmer air is LESS DENSE – low pressure
Cooler air is MORE DENSE – high pressure

9. cloud particles become too heavy to remain suspended in the air
PRECIPITATION
Rain
liquid precipitation
Hail
Ice precipitation - Thunderstorms
Freezing rain
Starts as snow, melts, then refreezes after passing through a THIN cold layer (freezes on contact w/ground)
Sleet
Starts as snow, melts, then refreezes before hitting the ground
Snow
Starts out frozen and stays frozen
cloud particles become too heavy to remain suspended in the air

10. Sleet
Freezing Rain

11. Precipitation

12. Condensation Nuclei
The aerosol particle in the atmosphere around which a water droplet forms