EARTH SUN RELATIONSHIPS

CLIMATE AND WEATHER How 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 CLIMATE How 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 PATTERNS Why is climate important to life on Earth?

CLIMATE ZONES 4 types: 1: Tropical Climate Avg daily temp: 80°F Rains almost daily (avg rainfall: 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: 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