Presentation on theme: "Topic 3: Introduction to Earth’s Atmosphere"— Presentation transcript:
1 Topic 3: Introduction to Earth’s Atmosphere General Introduction: - Earth’s Atmosphere - Importance of the AtmosphereComposition of the Atmosphere: - Common Atmospheric Gases - Greenhouse Gases - Atmospheric Particulates
2 Topic 2: Introduction to Earth’s Atmosphere Vertical Structure of the Atmosphere - Temperature Structure - Vertical Composition - Vertical Pressure ProfileWeather and Climate - What is Weather? - What is Climate? - Weather and Climate Controls
3 The Earth’s Atmosphere The atmosphere is a mixture of gases surrounding the earthAtmospheric gases originate from gases released from the interior of the earth by volcanism and subsequently modified by plants and animalsAtmospheric gases are held in place by the force of gravity
4 The Earth’s Atmosphere Atmosphere may contain both solid and liquid impuritiesAtmosphere is densest at sea level and decreases with increasing altitudeHence, about 98% of atmospheric gases are found within 16 miles (or 26km) of the earth surface
6 The Earth’s Atmosphere Though earth atmospheric gases could be found as far away 6000 miles or 10,000 kmWhat is the actual extent of earth’s atmosphere?Hint: What is the orbital altitude of the International Space Station (ISS)?
7 The Earth’s Atmosphere Average orbital altitude of ISS is 400 kmMore than 50% of the mass of the atmosphere lies below 3.6 miles (5.6 km)The three dominant gases are: - Nitrogen (78%) - Oxygen (21%) - Argon (0.93%)
8 Importance of the Atmosphere It is the main source of oxygen and other gases needed by plants and animalsIt maintains water supply through the mechanism of the hydrological cycleIt prevents temperature extremes and functions as a great insulator
9 Importance of the Atmosphere It provides protection from cosmic or ultraviolet radiationIt provides protection from the impacts of small-sized meteorites by causing them to be incinerated through friction
11 Principal Gases of Earth’s Atmosphere FormulaPercent By VolumeNitrogenN278.08OxygenO220.95ArgonAr0.934Carbon DioxideCO20.036NeonNe0.0018HeliumHe0.0005MethaneCH40.0001KryptonKrHydrogenH2
12 Principal Gases of Earth’s Atmosphere FormulaPercent By VolumeNitrous OxideN2OTraceXenonXeCarbon MonoxideCOOzoneO3Sulfur DioxideSO2Water VaporH2O0-4 (variable)
13 Greenhouse Gases in the Atmosphere Greenhouse gases permit the passage of short-wave solar radiationThey disallow the passage of long wave infrared radiant energy from the earth surface from going back to spaceHence, radiant energy is allowed to accumulate to produce a warming effect or greenhouse effect
14 Greenhouse Gases in the Atmosphere Common greenhouse gases in the atmosphere include: - CO2 (75% of global warming) - Chlorofluorocarbon (CFC) (20%) - Methane (15-20%) - Water Vapor - Ozone
15 Greenhouse Gases in the Atmosphere Producers of >50% of greenhouse gases are:- European Union - Brazil - China - RussiaEmission of greenhouses gases continues to rise with increasing growth in population
16 Greenhouse Gases in the Atmosphere Effects of global warming include: - more rains and longer growing season in high latitudes (Scandinavia, Canada, Siberia) - hotter summers and severe droughts in American Midwest - rise in sea level and flooding of coastal areas like Louisiana
18 The Ozone Layer and CFCOzone (O3) is a triatomic oxygenIt forms a complete layer between 9 and 35 miles (15 – 55 km) above the earth surfaceThe ozone layer protects plants and animals from ultraviolet radiation in sun’s rays by absorbing the radiation
19 The Ozone Layer and CFCBut ozone is a very fragile gas that can easily be destroyed naturally by: - sunspot cycle - oscillation of stratospheric wind - volcanic dust particles - effects of El NinoOr human use of CFC in: - refrigeration & air-conditioning - aerosol sprays - foam & plastic manufacturing
20 More rapid ozone depletion has been reported at the poles The Ozone Layer and CFCToday, 5% more UV radiation gets to the earth surface than in 1969Up to 5% of the ozone layer has been destroyed over much of the United StatesMore rapid ozone depletion has been reported at the polesSince 1975, Antarctic ozone hole has been found and appears to be persistent
22 Causes CFC to set chlorine free The Ozone Layer and CFCWithin the ozone layer, CFC becomes unstable and easily broken down by UV radiationCauses CFC to set chlorine freeChlorine pulls off oxygen atom from ozone to change it to an oxygen molecule and a chlorine monoxide molecule
24 The Ozone Layer and CFCA free oxygen atom pulls an oxygen atom off chlorine monoxide moleculeFreed chlorine atom attacks another ozone moleculeOne molecule of chlorine can destroy up to 100,000 molecules of ozoneIncrease of CFC in the ozone layer is causing the rapid loss of the ozone layer
26 The Ozone Layer and CFCOzone depletion is more severe over the polar region because of: - extreme cooling of the poles in winter, especially the Antarctica, where whirling winter pattern (vortex wind) occur - the presence of stratospheric ice crystals forming polar stratospheric clouds increases the process
27 The Ozone Layer and CFC- the ice crystals form surfaces for the accumulation of chlorine-based molecules and allowing spring uv radiation to trigger ozone depletion processOzone depletion is less over Arctic than the AntarcticaKey ozone depletion areas: Antarctica, Australia, mountainous regions of Europe, Central Canada and New Zealand
28 The Ozone Layer and CFCOzone depletion is highly correlated with increased levels of UV radiationGround levels of UV radiation (or UV Index) are now established and useful for alerting on possible health risks
31 The Ozone Layer and CFCA number of efforts to protect the ozone layer include: - ban of the use of aerosol sprays in Canada and U.S. in the 1987 Montreal Protocol on Substances That Deplete Ozone Layer set a timetable to phase out all major ozone-depleting substances - ban of CFC use in 1996 & substitution with hydrochlorofluorocarbon (HCFC)
32 The Ozone Layer and CFC Since 2006, the loss of ozone is stabilizing It is suggested in 2009 that the levels of ozone over the tropics would have become depleted to levels found in the poles by the year 2100
33 The Ozone Layer and CFCSome of the effects of exposure to ultraviolet radiation include: - causes skin cancer & damage to animal tissue - causes gene mutation - suppression of human immune system - causes eye problems including cataracts
34 - causes drop in crop yield worldwide The Ozone Layer and CFC- causes marine deserts- causes drop in crop yield worldwide
35 Air PollutionHuman activities have altered the composition of the atmosphere, especially in the citiesNatural sources of pollution include: - smoke from wildfires - ash from volcanic eruptions - windblown dust storms - plant pollen & salt particles in waves
36 Air PollutionThere are two general types of air pollution: - Primary pollution: (pollutants, such as particulates, sulfur or nitrogen compounds, carbon oxides and hydrocarbons, released directly into the air) - Secondary pollution: (caused by chemical reactions in the atmosphere like photochemical smog)
38 Primary Pollutants: Atmospheric Particulates Sources of Atmospheric Particulates: - meteoric dusts - volcanic dusts and ash - wind blow surface materials - smoke from bush fires - salt crystals from sea sprays - particles of biological origin (pollen, spores, seeds & bacteria) - particles of human origins (factory smoke, automobile emissions, heating, etc)
39 Primary Pollutants: Effects of Particulates in the Atmosphere The effects includes: - reduction of solar energy reaching earth’s surface due to absorption and reflection of sunlight - optical effects on low-angled rays to produce colorful sunrise and sunset
40 Primary Pollutants: Effects of Particulates in the Atmosphere - absorption of water (hygroscopic) and may form condensation nuclei - hazy conditions & atmospheric smog
41 Primary Pollutants: Carbon Monoxide Produced by the combustion of fossil fuels by automobile and industrial plantsCould be fatal if CO enters the bloodstream
42 Primary Pollutants: Sulfur Compounds May be natural in origin through releases by volcanoes or hydrothermal vents (Yellowstone National Park)May be of human origin through the burning of coal and petroleumSO2 may react in the atmosphere to form secondary pollutants like sulfur trioxide or sulfuric acid to form acid rain
43 Primary Pollutants: Sulfur Dioxide Sulfur dioxide is corrosive and a major lung irritant
44 Primary Pollutants: Nitrogen Compound Nitric oxide form through: - natural biological processes in water or soils - combustion in automobile enginesNitrogen dioxide gives polluted air its yellow or reddish-brown colorNitrogen dioxide may aid the production of smog by forming NO & leftover oxygen atom joins with O2 to form Ozone needed in photochemical smog
45 Primary Pollutants: Nitrogen Compound Nitric oxide may react with VOC to form peroxy-acetyl nitrate (PAN)PAN may cause crop and forest damages
46 Primary Pollutants: Photochemical Smog Nitrogen dioxide and hydrocarbons (or volatile organic compounds – VOC) contribute to the formation of photochemical smogPresence of ozone gives the smog its distinctive odorCauses damage to vegetation, corroding building materials, damaging sensitive human tissues (eyes, lungs and noses)
47 Vertical Composition of Atmosphere The composition & percentage of gases in the lower 50 miles (80 km) of the atmosphere are homogenous & uniformThis is the homosphere and includes: - Troposhere - Stratosphere - Mesosphere
49 Vertical Composition of Atmosphere The composition and percentage of gases above 50 miles (80 km) are non-uniform due to little or no vertical mixingThis is the heterosphereGases in heterosphere are layered according to their molecular mass
50 Vertical Composition of Atmosphere The layered gases in the heterosphere: - Hydrogen (Top) - Helium - Oxygen - Nitrogen (Bottom)Ozonosphere is a continuous layer of maximum ozone concentration between 9 and 30 miles (15 and 48 km)
51 Vertical Composition of Atmosphere Ionosphere is a deep layer of high concentration of electrically charged gases (ions) between 40 & 250 miles (60 & 400 km)Ionosphere is important because: - it aids long distance communication by reflecting radio waves back to earth - it’s known for its auroral displays (northern lights – Aurora Borealis)
52 Vertical Distribution of Gases in the Atmosphere
54 Vertical Pressure of Atmosphere Atmospheric pressure is highest at sea levelPressure decreases rapidly with altitude but not at a constant rateRate of change is rapid in lower atmosphere and diminishes significantly at the upper atmosphere
58 Vertical Temperature Profile of the Atmosphere The atmosphere consists of 5 thermal layers where temperature either increases or decreases with altitudeThe thermal layers are: - Troposphere - Stratosphere - Mesosphere - Thermosphere - Exosphere
60 Vertical Temperature Profile of the Atmosphere: Troposphere It’s the lowest thermal layerIt’s about 11 miles (18 km) thick above the equatorIt’s progressively thinner towards the poles where it is only 5 miles (8 km) thickThickness is related to temperature
62 Vertical Temperature Profile of the Atmosphere: Troposphere Hence, troposphere is thickest at the equator where temperature is highand one mile thicker in summer due to higher temperatureThe upper limit of troposphere is called the tropopause
63 Vertical Temperature Profile of the Atmosphere: Troposphere Temperature decreases with increasing altitude or the higher you go, the cooler it becomesHence, temperature at the bottom of this layer (earth surface) is about 60o F (15o C)and temperature at the top of this layer (tropopause) is about - 60o F (-51o C)
64 Vertical Temperature Profile of the Atmosphere: Troposphere It contains almost all the water vapor and clouds in the atmosphereAlmost all weather phenomena and processes occur in this layerAll precipitations originate in this layerAccounts for 80% of atmospheric mass
65 Vertical Temperature Profile of the Atmosphere: Stratosphere Extends beyond the tropopause to about 30 miles (48 km) above sea levelIt’s the zone of maximum ozone concentrationTemperature increases with increasing altitude or the higher you go, the hotter it becomes
66 Vertical Temperature Profile of the Atmosphere: Stratosphere Temperature at stratopause (top of layer) is 32o F (0o C)Source of heat for this layer is at the stratopause where absorption of UV radiation by ozone occursLittle or no vertical mixing but strong horizontal winds called Jet Streams occur
67 Vertical Temperature Profile of the Atmosphere: Mesosphere Extends beyond stratopause to about 50 miles (80 km) above sea levelTemperature decreases with increasing altitudeTemperature at the top of the layer (mesopause) is about -120o F (-84o C)
68 Vertical Temperature Profile of the Atmosphere: Thermosphere Extends beyond mesopause and gradually merges with exosphereTemperature initially remains constant at about -120o F (-84o C) up to about 90 km above sea level then begins to increase with altitude
69 Vertical Temperature Profile of the Atmosphere: Thermosphere At about 125 miles (200 km), temperature may be more than 2000o FHeat is obtained through absorption of UV radiation by ionized gases in this layer
70 What is weather?It is the short-term condition of the atmosphere of a placeIt is the sum of temperature, humidity, cloudiness, precipitation, winds, & storms of a place for a given short time periodIt refers to atmospheric conditions over short time periods like: few hours, a day, a week, a month, a year or a season
71 What is weather?Weather usually applies to a small area like a cityWeather changes constantly because of changing atmospheric circulationGlobal warming is causing weather-related disasters like drought, floods, tornadoes, & ice storms to become more frequent and intense
72 What is Climate?Climate is the average weather condition of a place observed over a period of at least 30 yearsClimate also includes those extreme conditions or deviations from the average condition
73 What is Climate?It is said that “climate is what you expect; weather is what you get”Climatic elements are the same as weather elements except that the former is the average valueWeather and climate have direct influence on agriculture, transportation and human life
74 What is Climate?Changes in weather and climatic elements are controlled by certain attributes of the earth surface called weather or climate controls
75 Weather and Climate Controls Weather and climate elements like:- Temperature - Pressure - Wind - Humidity - Precipitationchange over time and spaceCertain attributes of the earth surface called weather or climate controls cause these changes to occur
76 What is Climate?Weather and climate controls include: - Latitude - Land and Water - Atmospheric Circulation - General Circulation of Oceans - Altitude - Topographic Barrier - Storms - Earth’s Rotation
78 Major Weather & Climatic Elements and Their Controls TemperatureLatitudePressureDistribution of land and waterWindGeneral circulation of atmosphere, land & waterMoisture ContentGeneral circulationElevationDistance from the seaStormsTopographic barriers
79 Weather & Climate Control: Latitude Latitude controls temperature because it determines the amount of solar energy received at a placeLatitude does that through its direct influence on: - solar altitude - length of daylight
81 Weather & Climate Control: Latitude Solar altitude or the angle of sun’s rays is closely related to latitudeLow latitudes receive higher solar energy because of their relatively higher solar altitudeLength of daylight is also closely related to latitude with more solar energy receipt on longer summer days (at the poles)
82 Weather & Climate Control: Latitude Lower latitudes (tropics) receive more solar energy because sun’s rays are more directHigher latitudes receive less solar energy or more loss of energy because: - sun’s rays are more oblique - of atmospheric obstruction of oblique sun’s rays traveling longer distances through the atmosphere
83 Latitude, Angle of Incidence and Atmospheric Obstruction
84 Weather & Climate Control: Land and Water Land and water tend to control the temperature and moisture content (humidity & precipitation) of a placeWater bodies impose milder and a fairly uniform temperature regime on their surroundings (maritime influence)Water has higher specific heat (5x) than land
85 Continentality and Maritime Effects on Daily Temperature Patterns
86 Weather & Climate Control: Land and Water Whereas, Land mass imposes a highly variable temperature regime on its surrounding (continentality effect)For example, land heats up more rapidly in summer to produce high summer temperatures and cools off very quickly in winter to produce low winter temperatures
87 Weather & Climate Control: Land and Water Water bodies are major sources of moisture in the atmosphereHence maritime areas are more humid, while continental land interiors tend to be drier
88 Weather & Climate Control: Atmospheric Circulation Atmospheric circulation controls temperature and moisture content of a placeThe movement of air masses re-distribute atmospheric moisture and heatFor example, cold Canadian air mass causes temperature to plummet in Edwardsville
90 Weather & Climate Control: Atmospheric Circulation Whereas, warm tropical air mass from Gulf of Mexico raises the temperatureCold air mass is relatively drier & tends to bring dry conditions to an areaWarm tropical air mass with plenty of moisture brings precipitation to an area
92 Weather & Climate Control: General Circulation of the Oceans Ocean currents help in the meridonal transfer of heatWarm ocean currents transfer heat to the polesCold currents transfer cool water towards the equator
95 Weather & Climate Control: General Circulation of the Oceans Cold ocean currents are commonly found along the west coast of continents and tend to control the weather and climates of the adjoining coastal areasFor example, Cold Humboldt is the cause of the adjoining Peruvian desert climate
96 Weather & Climate Control: General Circulation of the Oceans and Cold Benguela current is the cause of the adjoining Kalahari desertWarm currents are common along the east coast of continents and they are often associated with moister conditions
97 Weather & Climate Control: Altitude Temperature, Pressure and moisture conditions are partially controlled by elevationIn general, temperature, pressure and moisture tend to decrease with altitude
98 Weather & Climate Control: Topographic Barrier Topographic barriers like mountains have blocking and diverting effects on weather and climateWindward sides of mountains tend to receive more precipitation than expected due to their orographic effects (western slope California mountains)
99 Weather & Climate Control: Topographic Barrier Whereas, The leeward side of the mountain receives little or no rain because of rain shadow effect (e.g. Nevada desert)In temperate regions, south facing slopes receive more sunlight than north facing slopes
100 Weather & Climate Control: Storms Each type of storm imposes different weather conditionsFor example, hurricanes, tornadoes, thunderstorms, etc produce different weather conditions
101 Weather & Climate Control: Earth’s Rotation Earth’s rotation imposes coriolis effect on the flow path of air and waterFor example, coriolis effects causes wind to:- flow from the east in the tropics - from the west in temperate latitudes
105 1) The main surface currents in the major ocean basins assist in the heat transfer around the world by movingwarm water from the Northern Hemisphere to the Southern Hemisphere.cool water from the poles to the tropics.warm water from the poles to the tropics.cool water from the tropics to the poles.warm water from the Southern Hemisphere to the Northern Hemisphere.Figure 3-18
106 1) The main surface currents in the major ocean basins assist in the heat transfer around the world by movingwarm water from the Northern Hemisphere to the Southern Hemisphere.cool water from the poles to the tropics.warm water from the poles to the tropics.cool water from the tropics to the poles.warm water from the Southern Hemisphere to the Northern Hemisphere.Level of Difficulty: 2Text Reference: Weather and ClimateGeography Standard: 7Blooms Taxonomy: SkillsFigure 3-18Explanation: Northerly ocean currents from the poles to the tropics transport coolerwater from higher latitudes to lower latitudes.
107 2) An example of climate (versus weather) for a given area is the air temperature reached 78°F today.rain showers are predicted for next Saturday.the record high temperature is 122°F.the average rainfall in April is 15 inches.thunderstorms occurred last Mother’s day.
108 2) An example of climate (versus weather) for a given area is the air temperature reached 78°F today.rain showers are predicted for next Saturday.the record high temperature is 122°F.the average rainfall in April is 15 inches.thunderstorms occurred last Mother’s day.Level of Difficulty: 2Text Reference: Weather and ClimateGeography Standard: 4Blooms Taxonomy: SkillsExplanation: Climate describes weather conditions over a long period. So, anaverage weather condition over a span of many months would be a climate condition
109 3) Temperature decreases with increasing elevation in which thermal atmospheric layers? Troposphere and stratosphereThermosphere and mesosphereTroposphere and mesosphereTroposphere onlyStratosphere and thermosphere
110 3) Temperature decreases with increasing elevation in which thermal atmospheric layers? Troposphere and stratosphereThermosphere and mesosphereTroposphere and mesosphereTroposphere onlyStratosphere and thermosphereLevel of Difficulty: 3Text Reference: Vertical Structure of the AtmosphereGeography Standard:Blooms Taxonomy: IdentificationFigure 3-5Explanation: In Figure 3-5, we see that temperature values decrease as you ascendin the image. Through the remaining layers, temperature increases with height.
111 4) _______ is the most plentiful variable gas in the atmosphere 4) _______ is the most plentiful variable gas in the atmosphere However, it varies in location, not in time.NitrogenOzoneCarbon dioxideOxygenWater vapor
112 4) _______ is the most plentiful variable gas in the atmosphere 4) _______ is the most plentiful variable gas in the atmosphere However, it varies in location, not in time.NitrogenOzoneCarbon dioxideOxygenWater vaporLevel of Difficulty: 2Text Reference: Composition of the AtmosphereGeography Standard: 7Blooms Taxonomy: KnowledgeExplanation: Water vapor in the atmosphere is highly variable, falling out asprecipitation and being replenished by water sources. Its composition can vary from 0-4% of the total atmosphere.
113 5) Oxygen accounts for what proportion of the of the volume of gases in the atmosphere? 21%78%0.037%1-4%0.9%Figure 3-1
114 5) Oxygen accounts for what proportion of the of the volume of gases in the atmosphere? 21%78%0.037%1-4%0.9%Level of Difficulty: 2Text Reference: Composition of the AtmosphereGeography Standard: 7Blooms Taxonomy: KnowledgeFigure 3-1Explanation: While oxygen is the most important element for life, it makes up arelatively small percentage of the atmosphere when compared to nitrogen.
115 6) If a wind of 55 mph were subjected to a Coriolis force that is double what exists on Earth, what would its new speed be?110 mph27.5 mph45 mph0 mph55 mphFigure 3-22
116 6) If a wind of 55 mph were subjected to a Coriolis force that is double what exists on Earth, what would its new speed be?110 mph27.5 mph45 mph0 mph55 mphLevel of Difficulty: 4Text Reference: Weather and ClimateGeography Standard: 7Blooms Taxonomy: KnowledgeFigure 3-22Explanation: The Coriolis force affects the direction of motion, but not the speed.Doubling the Coriolis force will not affect the speed of the wind.
117 7) The aurora borealis typically occurs in the homosphere.the troposphere.the ionosphere.the stratosphere.the mesosphere.Figure 3-10
118 7) The aurora borealis typically occurs in the homosphere.the troposphere.the ionosphere.the stratosphere.the mesosphere.Level of Difficulty: 2Text Reference: Vertical Structure of the AtmosphereGeography Standard: 7Blooms Taxonomy: KnowledgeFigure 3-10Explanation: In the ionosphere, charged particles interacting with ultraviolet solarRadiation cause these particles to glow, forming the aurora phenomena.
119 8) Which of the following is an example of a secondary pollutant? Carbon monoxideCarbon dioxideParticulatesSmogCFCsFigure 3-15
120 8) Which of the following is an example of a secondary pollutant? Carbon monoxideCarbon dioxideParticulatesSmogCFCsLevel of Difficulty: 3Text Reference: Human-Induced Atmospheric ChangeGeography Standard: 7Blooms Taxonomy: KnowledgeFigure 3-15Explanation: Secondary pollutants form as a result of a process from a primarypollutant. Smog forms when smoke mixes with fog, so it is a secondary pollutant.
121 9) Ozone is depleted by CFCs 9) Ozone is depleted by CFCs. What is the primary atom in the CFC molecule that is responsible for ozone depletion?OxygenFluorideFluorineChlorideChlorine
122 9) Ozone is depleted by CFCs 9) Ozone is depleted by CFCs. What is the primary atom in the CFC molecule that is responsible for ozone depletion?OxygenFluorideFluorineCchlorideChlorineLevel of Difficulty: 4Text Reference: Human-Induced Atmospheric ChangeGeography Standard: 7Blooms Taxonomy: SkillsFigure 3-12Explanation: The chlorine atom in a CFC molecule attracts oxygen atoms fromozone, causing the ozone molecule to break into a regular oxygen molecule, resulting in ozone depletion.
123 10) Los Angeles, California and Dallas, Texas have vastly different climates, despite existing at the same latitude. What causes the climate difference?Proximity to a desertSun is more directly overhead in DallasLos Angeles is near mountainsDallas is in the PlainsDallas is continental; Los Angeles is maritime.
124 10) Los Angeles, California and Dallas, Texas have vastly different climates, despite existing at the same latitude. What causes the climate difference?Proximity to a desertSun is more directly overhead in DallasLos Angeles is near mountainsDallas is in the PlainsDallas is continental; Los Angeles is maritime.Level of Difficulty: 2Text Reference: Weather and ClimateGeography Standard: 4Blooms Taxonomy: SkillsExplanation: LA’s proximity to water allows for a less variable climate in terms oftemperature. In general, maritime regions have a less volatile climate than continental regions.
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