Presentation on theme: "Chapter 17 Atmosphere Page 365 What does the photograph show?"— Presentation transcript:
1Chapter 17 Atmosphere Page 365 What does the photograph show? How does the quality of the air in the photograph compare to that of your community today?How might the photograph be different if it was taken on the following day?What makes up the atmosphere?How do human activities affect the atmosphere?
4The atmosphere in Balance The early atmosphere of the earth was primarily created through volcanic eruptions.Consisted mostly of CO2, SO2, H2O, and NitrogenOxygen was thought to have been created in the upper atmosphere by the destruction of water molecules through PhotosynthesisToday’s atmosphere (99%) is mostly nitrogen and oxygen
5Recycling of Atmospheric materials Composition of the atmosphere changes very little because it is an efficient recycling systemP. 367 Picture explains the O2, CO2, and H2O cycles
9A Delicate BalanceThe atmosphere may become unbalance by both natural and human originse.g. CO2 levels in Hawaii have rose 16% between 1959 and 1999
10Environmental Consultant Median annual earnings of environmental scientists were $51,080 in May The middle 50 percent earned between $39,100 and $67,360. The lowest 10 percent earned less than $31,610, and the highest 10 percent earned more than $85,940.Median annual earnings of hydrologists were $61,510 in May 2004, with the middle 50 percent earning between $47,080 and $77,910, the lowest 10 percent earning less than $38,580, and the highest 10 percent earning more than $94,460.Median annual earnings in the industries employing the largest number of environmental scientists in May 2004 were as follows:Federal Government$73,530Management, scientific, and technical consulting services51,190Architectural, engineering, and related services49,160Local government48,870State government 46,850
11Chapter 17.2 Page 696 Convert 70°F Celsius When is the Fahrenheit Scale used?The Celsius Scale?Which do you prefer?
12Heat and the Atmosphere Energy from the sun drives the atmosphere
13How Heat MovesRadiation – transfer of energy through space in the form of visible lightdoes not require a medium – pass through a vacuumConduction – transfer of heat energy by touche.g. air bough warm ground becomes warmerConvection – Transfer of heat energy in a liquid or gas caused by differences in densitye.g. warm air heated by the surface of earth becomes less dense and rises
14Heat and TemperatureTemperature – is the measure of the average K.E. of the atoms in the substanceHeat is the total KE of all the particles in a substancee.g. A tablespoon of water at 100 Celsius has less heat than a cup of water at 100 CelsiusThermometer is used to measure temperatureAt sea level water freezes at 0 Celsius and Boils at 100° Celsius
15Structure of the Atmosphere is divided into 4 layers based on temperature p. 371
16Troposphere – lowest layer of the atmosphere where all weather occurs Temperature decreases with height
17Stratosphere – clear dry layer above the Troposphere Contains the Ozone(O3) Which absorbs UV radiationTemperature increases with increased height
18Mesosphere - the 3rd layer Temperature decreases with height
19Thermosphere – 4th layer very thin and separated by layers of different gassesdue to the intense solar radiation temperature increases with heightcontain the ionosphereAuroras are formed when electrically charged particles are attracted to the earth’s poles
20Insulation and the Atmosphere Incoming solar radiation is called insulationEarth receives only two-billionths of the suns raysOf 100 units (p. 373) of suns energy 30 reflected back into space, 19 Absorbed by the atmosphere, 51 absorbed by Earth’s surfaceUnequal insulation caused temperature differences
21Discussion – Global Heat Budget Page 373Explain why most of the atmosphere’s heat energy comes indirectly from the sun.
22Chapter 17.3 Which surface is likely to be hotter on a sunny day: A parking lot blacktopOne with crushed white gravel
23Local Temperature Variations Caused by insulation (energy) heats Earth’s surface and atmosphere unequally
24Intensity of Insulation The angle at which the suns rays strike the earth, the more overhead (90) the more energyTime of day - Suns rays are closest to vertical at noon. However, the highest temperature occur later in the day because of time needed for the surface to create heat using the insulationLatitude and equator 90 more insulation where as high latitude sun rays strike at more of an angle less insulation
25Time of year – mid latitude locations have higher temperatures in summer because the rays are more direct than in winterYear’s maximum insulation occurs in June but max temperate are in July, weakest sunlight in December but lowest temps are in JanuaryCloud Cover – more insulation on clear days because clouds reflect sunlight. However, they hold the heat in at night.
26Heating of Water and Land Water and land warm up and cool off at different rates. Water warms more slowly than land and cools more slowly.Suns energy penetrates water deeper spreading it outSome energy is used in evaporationWater has a higher specific heatDifferent hard surfaces absorb radiation differentlylight colored surfaces absorbs less than darke.g. blacktop gets warmer than grass
27Temperature Maps (p. 377)Land heats and cools off faster than water therefore continents are warmer than nearby oceans in summer and cooler than nearby oceans in winterIsotherm lines on a map connect places of equal temperatures
30Common Air PollutantsAir Pollution – any airborne gas or particle that occurs at a concentration capable of harming humans or the environmentClean air act 1970 Identifies 6 key pollutants – CO, NO2, SO2 Pb, O3 and particulates
31Acid Rain – Forms when sulfur dioxide and nitrogen oxides react with water vapor in the air. Then falls out with rain and snowLife forms are sensitive to pHpH scale 0-14 each increase is 10x the priorIncreased Acid has killed off lakes in Canada and in upper New YorkCan also damage limestone structures
32Smog - Photochemical Smog - brown haze that forms in air pollution with nitrogen oxides and hydro carbons that come mainly from carsCreates ground level zones – irritant to lungs and stunts plant growth and yieldsTemperature inversion – air at surface is colder than the air above trapping pollutants close to the ground
33Ozone DepletionThought to be caused by Chlorofluorocarbons. CFC’S are used in aerosols, air conditioners, and solvents that are banned in the U.S.Ozone absorbs UV form the sun that cause skin cancer in humans
34Global WarmingGreen house gases such as CO2 trap heat at the earth’s surfaceGasses could be increased form the burning of fossil fuels and global deforestation.Possible effectsRising seal levelsIncreasing frequency and severity of stormsMore frequent heat waves and droughtsRelocation of major crop-growing areas