Lesson #8 Climate & Weather Patterns

Earth & Space Science

Lesson #8 Climate & Weather Patterns

• Factors that affect climate:– Latitude– Elevation (Altitude)– Proximity to Large Body of Water– Ocean Currents– Mountains– Planetary wind and pressure belts– Amount of moisture in the Atmosphere– Pollution

Lesson #8 Climate & Weather Patterns

• How does Latitude affect Climate?– Climate is warmer as you move

closer to the equator.

(Image from http://web.gccaz.edu/~lnewman/gph111/topic_units/Earth_Sun/Earth_Sun2.html)

• Sun’s rays hit the Earth more directly at the equator. So, the sun’s energy is more intense here.

• As you move further away from the equator, the angle decreases. So, the sun’s rays are more indirect.

Lesson #8 Climate & Weather Patterns

• How does Elevation (Altitude) affect Climate?– The higher up you go, the

colder it will be.• Air pressure decreases as you

move higher up.• As air pressure decreases, the

rising air expands (air molecules

spread out) and cools.

(Image from http://radar.weather.gov/jetstream/atmos/pressure.htm)

Lesson #8 Climate & Weather Patterns

– The closer you are to a large body of water (lakes/oceans), the more moderate the weather.

• This is because the temperature of the water influences the air temperature above it.

• How does Proximity to Large Body of Water affect Climate?

Lesson #8 Climate & Weather Patterns

– This also explains Lake Effect Snow• As cold air (cold wind) flows over the warm lake water, the

warm water heats the air’s bottom layer as lake moisture evaporates into the cold air.

• Since warm air is lighter or less dense than cold air, the heated air rises and begins to cool

• As the air cools, the moisture that evaporated into it condenses and forms clouds and snow as it passes over the colder land areas.

(Image from http://earthsys.ag.ohio-state.edu/project/GLair/precipitation/snow/snow.html)

• How do Ocean Currents affect Weather?

Lesson #8 Climate & Weather Patterns

– Gulf Stream

Lesson #8 Climate & Weather Patterns

• How do Mountains affect Weather?– Windward side of

mountains are cooler and wetter than the leeward side.

(Image from http://egsc.usgs.gov/isb/pubs/teach-pack/volcanoes/lesson3/lesson3.html)

• How do planetary winds affect climate?

Lesson #8 Climate & Weather Patterns

– Planetary winds distribute heat and moisture around the Earth.

• Move warm air toward the pools and cool air toward the equator

(Image from http://egsc.usgs.gov/isb/pubs/teach-pack/volcanoes/lesson3/lesson3.html)

• How do pressure belts affect climate?– Low-pressure zones lead to cloud formation that

drop precipitation as rain or snow

Lesson #8 Climate & Weather Patterns

(Image from http://web.gccaz.edu/~lnewman/gph111/topic_units/Pressure_winds/pressure/pressure2.html)

Lesson #8 Climate & Weather Patterns

• How does the amount of moisture in the atmosphere affect weather?

– Tornadoes• Tornadoes form when

warm moist air meets cool dry air. When the two meet, they create an unstable atmosphere with strong and violent winds.

(Image from http://egsc.usgs.gov/isb/pubs/teach-pack/volcanoes/lesson3/lesson3.html)

Lesson #8 Climate & Weather Patterns

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– Tornadoes• Tornadoes form when

warm moist air meets cool dry air. When the two meet, they create an unstable atmosphere with strong and violent winds. Warm air at the center of the tornado quickly rises, sucking in air and objects.

(Image from http://egsc.usgs.gov/isb/pubs/teach-pack/volcanoes/lesson3/lesson3.html)

Lesson #8 Climate & Weather Patterns

• How does pollution affect weather?

– Global warming• Greenhouse effect

(see lesson 8_earth processes)

(Image from http://egsc.usgs.gov/isb/pubs/teach-pack/volcanoes/lesson3/lesson3.html)