EARTH SUN RELATIONSHIPS

CLIMATE AND WEATHERHow do the relationships btwn Earth and the sun affect climate?

WEATHER• Def: condition of the

atmosphere in one place during a short period of the time

• How do you tell what the weather is like?----Look out the window

CLIMATE• Def: weather patterns typical

for an area over a long period of time

• Directly affected by Earth/Sun relationships

EARTH’S TILT AND ROTATION• AXIS: imaginary line; runs

through center of Earth btwn N and S Poles

• Earth tilts on the axis at 23.5°

• Affects amount of direct sunlight, which affects temperature

• Our rotation takes 24 hours

EARTH’S REVOLUTION• REVOLUTION: in astronomy,

the Earth’s yearly trip around the sun

• 365 ¼ days

• Tilt and revolution affect amt of sunlight that hits the Earth

EQUINOX• Def: one of 2 days on which

the sun is directly above the Equator, making day and night equal in length

• Around March 21 and September 23

• Mark the shift in seasons

SOLSTICE• Def: one of 2 days on which

the sun’s rays strike directly on the Tropic of Cancer or the Tropic of Capricorn

• June 21: Summer Solstice---longest day in N. hemisphere

• December 22: Winter Solstice---shortest day

MIDNIGHT SUN• C. March 20-September 23

• North of Arctic Circle (66 1/2°N) has continuous daylight

• South Pole for the other 6 months

GREENHOUSE EFFECT• Radiation from sun heats the

Earth

• Water vapor, methane, and CO2 trap some of the radiation

• This causes temps to rise

FACTORS AFFECTING CLIMATEHow are climate patterns related to each zone of latitude?

LATITUDE AND CLIMATE• Low latitudes: btwn 30°S and

30°N---get direct sun rays year-round; warm to hot climates

• High latitudes: 60°N to 90°N and 60°S to 90°S---the Poles; get continuous, but indirect sun

• Midlatitudes: btwn 30°N and 60°N (vice versa for S)---most variable weather

ELEVATION AND CLIMATE• Earth’s atmosphere thins as

altitude increases

• Retains less heat

• Temp decreases 3.5°F for every 1000 ft. up

WINDS• Wind is air moving across

surface of Earth

• Sunlight heats atmosphere unevenly

• Warm air rises, creating areas of low pressure

• Cool air sinks, causing high pressure

• Air moves along the warm and cold, distributing the sun’s energy around the planet

WIND PATTERNS• PREVAILING WINDS: wind in

a region that blows in a fairly constant directional pattern

• Determined by latitude and Earth’s movement

• CORIOLIS EFFECT: resulting deflection of prevailing winds caused by Earth’s rotation

• DOLDRUMS: a frequently windless area near the Equator

OCEAN CURRENTS• Def: cold or warm stream of

seawater that flows in the oceans, generally in a circular pattern

• Cold water from Poles move toward Equator

• Warm water from Equator moves toward Poles

INFLUENCES ON WEATHER• Climate affected by recurring

events

• EL NIÑO: periodic reversal of the pattern of ocean currents and water temperatures in the mid-Pacific region

LANDFORMS AND CLIMATE• Large bodies of water keep

temps moderate

• Mountain ranges push wind up, creating precipitation

• Rain falls on WINDWARD side

• Winds then move down the LEEWARD side

• Creates a RAIN SHADOW: dry areas on the leeward side of mtns

WORLD CLIMATE PATTERNSWhy is climate important to life on Earth?

CLIMATE ZONES• 4 types:

• 1: Tropical Climate

• Avg daily temp: 80°F

• Rains almost daily (avg rainfall: 50-260 inches annually)

• Thick vegetation

• Abundant wildlife

CLIMATE ZONES CONTINUED• 2: Dry Climates

• 2 main types

• A: Semi-arid (steppe) : located away from oceans

• Avg rainfall: 10-30 inches

• Warm summers, harsh winters

• B: Desert: avg rainfall---10 inches

• Very little plant/animal life

STILL MORE CLIMATE ZONES• 3: Midlatitude climate:

• Includes: a) Humid subtropical—high humidity; mild winters; year-round rain

• Vegetation: prairies

• --Coniferous trees: cone-bearing; needle shaped leaves

• --Deciduous trees: broad leaf

MIDLATITUDES CONTINUED• B) Marine west coast climate

• Cool summers; cool, damp winters

• Abundant rainfall

• Mixed forests

• C) Mediterranean climate

• Mild, rainy winters; hot, dry summers

• Vegetation: woody bushes and short trees

MIDLATITUDES CONTINUED• D) Humid continental

• Inland, so not affected by ocean winds

• Farther north, harsher winters and cooler summers

• Vegetation: mixed

HIGH-LATITUDE CLIMATES• Freezing temps year-round

• Includes:

• A) Subarctic climates

• Has PERMAFROST: permanently frozen layer of soil

• B) Tundra climate

• Very limited heat

• Vegetation: low bushes, moss, lichen

CLIMATE CHANGE• Major changes in climates over

extended periods of time

• Global temps have increased 1.4°F over last 100 years

• Causes severe weather changes

• Earth does have natural cycles of climate change

• Increased greenhouse gas emission creates acid rain

• Acid rain kills trees

• Fewer trees to scrub the air