Presentation on theme: "Climates of the Earth Pgs.55-69. Section 1: Earth- Sun Relationships Weather= The condition of the atmosphere in one place during a limited period of."— Presentation transcript:
Section 1: Earth- Sun Relationships Weather= The condition of the atmosphere in one place during a limited period of time. Climate= Term for weather patterns that an area typically experiences over a long period of time.
Section 1: Earth- Sun Relationships Earth’s Tilt & Rotation Axis= an Imaginary line running from the North Pole to the South Pole through the planet’s center. Currently tilted @ an angle of 23 ½ *. Temperature= the measure of how hot or cold a place is. Common temperature scales: Fahrenheit (*F) or Celsius (*C). Rotates every 24 hrs, west to east, 1 st one hemisphere & then the other toward the sun, alternating the light of day & the dark of night. http://player.discoveryeducation.com/index. cfm?guidAssetId=D621326A-36AB-47BF- 9CC7- 77BE8EB7589A&blnFromSearch=1&product code=USplayer.discoveryeducation.com/index. cfm?guidAssetId=D621326A-36AB-47BF- 9CC7- 77BE8EB7589A&blnFromSearch=1&product code=US
Section 1: Earth-Sun Relationships Earth’s Revolution Revolution= 1 complete trip around the sun. Seasons are reversed North & South of the equator. Around March 21 st the sun’s rays fall directly on the equator. Equinox= “equal night” daylight & nighttime hrs are equal. This day marks the beginning of spring in the northern hemisphere.
Section 1: Earth-Sun Relationships The Tropics of Cancer & Capricorn Tropic of Cancer=23 ½* N. latitude, northern most point on the Earth to receive direct rays of the sun. Summer Solstice= June 21 st; making this the longest day of sunlight in the northern hemisphere & marking the 1 st day of summer. Tropic of Capricorn=23 ½* S. latitude, southern most point on the Earth to receive direct rays of the sun. This equinox marks the beginning of fall in the northern hemisphere. Winter Solstice= December 22 nd. Shortest day of shortest daylight, begins the winter season in the N. hemisphere.
Section 1: Earth-Sun Relationships 6 months a yr 1 pole is tilted toward the sun & receives continuous sunlight while the other pole is tilted away from the sun & receives little or no sunlight. North Pole= sun never sets from March 20 th- September 23 rd. South Pole receives continuous daylight from September 23 rd – March 20 th. This is a phenomenon known as the Midnight Sun.
Section 1: Earth-Sun Relationships The Greenhouse Effect Greenhouse Effect= the capacity of certain gasses in the atmosphere to trap heat, thereby warming Earth. Global Warming= a rise in atmospheric CO2 levels along with a general rise in global temperatures.
Section 2: Factors Affecting Climate Latitude & Climate Low Latitudes: Area between the Tropics of Cancer & Capricorn. (includes the equator) receives direct sun rays all yr. Warm, hot climates, these are know as the Tropics. High Latitudes: Earth’s polar areas. Arctic Circle= latitude 66*N, continuous but indirct sunlight or twilight March 20 th - September 23 rd. Antarctic Circle= latitude 66*S, continuous but indirect sunlight or twilight September 23 rd - March 20 th. Mid-Latitudes= Between the Tropic of Cancer & the Arctic Circle & the Tropic of Capricorn & the Antarctic Circle. Temperate climates, fairly hot-fairly cold w/ dramatic seasonal changes.
Section 2: Factors Affecting Climate Elevation & Climate: At all latitudes elevation influences climate due to the relationship between the elevation of a place & its temperature. Wind & Ocean Currents: Air moving across Earth’s surface is wind. Rising Warm Air=Low Pressure. Falling Cool Air= High Pressure. Prevailing Winds= wind in a region that blows in a fairly constant directional pattern, determined by latitude & Earth’s movement. Coriolis Effect= an effect that causes the prevailing winds to blow diagonally rather than along strict north-south or east-west lines.
Section 2: Factors Affecting Climate Doldrums=At the Equator, global winds are diverted north & south leaving a narrow, generally frequently windless area near the Equator. Currents= cold or warm stream of seawater that flows in the oceans, generally in a circular pattern. Coriolis Effect is present here as well, causing the currents to move in a clock-wise motion in the N. Hemisphere & counter-clock-wise in the S. Hemisphere. El Nino= periodic change in the pattern of ocean currents & water temperatures in the Mid-Pacific region.
Section 2: Factors Affecting Climate Windward= the side of the mountain range facing the wind. Leeward= facing away from the direction from which the wind is blowing. Rain Shadow= dry area of land found on the leeward side of a mountain range.
Section 3: World Climate Patterns Natural Vegetation= The plant life that grows in an area where the natural environment is unchanged by human activity. The Tropics= hot & wet weather all yr. Avg. temp. 80* F. avg. rainfall 80 inches a yr! Dry Climates: Desert & Steppe Desert: sparse plant life, avg. rainfall less than 10 inches a yr. occur in less than 1/3 of Earth’s total land area. The Sahara extends over 1/3 of Africa. Oasis= area of lush vegetation. Steppe= treeless grasslands avg. rainfall: 10-20 in.
Mid-Latitudes: variable weather patterns & seasonal changes. Coniferous =Trees that have cones and needle- shaped leaves, keep their foliage year round. Deciduous= Trees that have broad leaves that change color & drop in the fall. Mixed forests= both kinds of trees. Costal latitudes are known as Mediterranean Climates; mild rainy winters, hot & sunny summers. Vegetation includes Chaparrals, thickets of woody bushes & short trees.
Section 3: World Climate Patterns High latitudes: freezing temperatures all year due to lack of sunlight. Subarctic Climate Region: bitterly cold winters, short cold winters. Permafrost= permanently frozen subsoil. Tundra: bitter cold for 6 months, located in N. Hemisphere. Low bushes, short grasses, & lichens. Highland Climates: The higher the elevation the colder the climate. Climate changes: human interaction. Burning of fossil fuels releases gases that fall in rain & snow. Smog= visible chemical haze