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Chapter 17 Atmosphere and Weather . Atmo = vapor Cirru = hairlike curls Strat = layer Cumul = heaped Alto = high Iso = equal Nimb = light (quick) Baro = weight Hygro = moist Meso = middle Trop = turn Therm = heat.
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Chapter 17 Atmosphere and Weather Atmo = vapor Cirru = hairlike curls Strat = layer Cumul = heaped Alto = high Iso = equal Nimb = light (quick) Baro = weight Hygro = moist Meso = middle Trop = turn Therm = heat
Weather = constantly changing; refers to the state of the atmosphere at any given time and place. Climate = weather patterns based on long periods of time; describes a place or region.
Composition of the Atmosphere • Major Components: • Nitrogen (78%) • Oxygen (21%) • Argon • Carbon Dioxide • All Others
Composition of the Atmosphere • Variable Components: • Water Vapor • Ozone • Pollution Air Pollution http://svs.gsfc.nasa.gov/vis/a010000/a010000/a010012/ Ozone Recovery http://www.amnh.org/sciencebulletins/
Temperature and Altitude Pg 480 Fig 6
How far does our atmosphere extend? Earth Moon
Height and Structure of the Atmosphere Pressure: Weight of air above. Closer to Earth’s surface = more pressure. Barometer = measures air pressure
Wind Speed • Measured on the Beaufort Scale • Relates wind speed to its effects • Wind chill factor Anemometers Sir Francis Beaufort
Relative Humidity • Hygrometer • Measures the amount of moisture in the air
Meteorology • Meteorologists study weather • How atmosphere heats and cools • How clouds form and produce rain • What makes wind blow • Composition of atmosphere • Cause of past and present climates http://www.youtube.com/watch?v=uYctRlQ0gOE&feature=related
Temperature Variations • Seasons • Sun’s rays do not strike surface evenly • Solstice vs. Equinox
Earth-Sun Relationships • Earth’s Motions • Rotation = spinning on its axis • Revolution = movement around the sun 23.5o Tilt Rotation Seasons are a result of the tilt of Earth’s axis remaining the same as the Earth revolves around the sun. Revolution
Vernal Equinox Days begin getting longer. Vernal Equinox March 21 Summer Solstice First official day of Summer. Winter Solstice Dec 21 Summer Solstice June 21 Autumnal Equinox Days begin getting shorter. Autumnal Equinox Sept 22 Winter Solstice First official day of Winter.
DAYLIGHT Vernal Equinox March 21 Spring and Fall Equinox: All latitudes receive 12 hours of daylight. Summer Solstice: Northern latitudes receive 24 hours of daylight. Winter Solstice Dec 21 Summer Solstice June 21 Winter Solstice: Northern latitudes receive 24 hours of darkness. Autumnal Equinox Sept 22
Radiation and Earth’s Atmosphere INCOMING RADIATION OUTGOING RADIATION 100% 8% 17% 6% 9% 40% 20% 19% 4% 6% 46% 15% 7% 24%
Earth Temperature At night, heat from the day is released from the Earth. Solar radiation is absorbed from the sun during the day. Clear night skies Partly cloudy night skies Cloudy night skies
Solar Radiation Reflection = radiation is sent back to space. Scattering = radiation is broken into smaller rays and scattered. Absorption = radiation is absorbed and retained. Scattering Reflection Absorption
Earth Temperature At night, heat from the day is released from the Earth. Solar radiation is absorbed from the sun during the day. Clear night skies Partly cloudy night skies Cloudy night skies
Greenhouse Effect • Trapping of the sun’s energy by the atmosphere • Caused by Greenhouse Gasses • CO2, Methane, CFCs • Burning fossil fuels • Coal, oil, & natural gas Global Warming!
Causes of the Greenhouse Effect http://environment.nationalgeographic.com/environment/global-warming/quiz-global-warming/ Eventually we will have a “lid” on our planet! Deforestation Burning Fossil Fuels CFC’s Industrial Pollution
17.3 Temperature Controls • Factors Affecting Atmospheric Temperature: • Latitude • Heating of Land and Water • Altitude • Geographic Position • Cloud Cover • Ocean Currents
Normal Lapse Rate 1° every 160m Temperatures also become cooler with altitude.
Temperature Inversion • Ground cools faster than air • Morning fog
Temperature Scales • Celsius: • 0° - 100° • Fahrenheit: • 32 °- 212 ° • Isolines: connect points of equal value on maps
Land, Water and Temperature… Land heats and cools more rapidly than water. Page 489 Fig 15
Geographic Position and Temperature… Windward locations are warmer than leeward locations. Page 490 Fig 16
Altitude and Temperature… Higher altitudes are colder than lower altitudes. Page 491 Fig 17
Human Influence and Temperature… Nat Geo Global Warming Shorts http://video.nationalgeographic.com/video/player/science/index.html
Cloud Cover, Albedo and Temperature… Albedo = fraction of total radiation that is reflected. Clouds reflect sunlight during the daytime and trap heat from the Earth at night. Disc Ed: Clouds and Patterns of the Weather [21:00]
World Temperatures Isotherms = lines that connect points that have the same temperature.