Atmosphere’s Structural Components & Characteristics AICE EM: Atmosphere Key Content 1

Decay of organic molecules from bodies and waste. (______cycle) Source of atmospheric nitrogen: ____________ Which cycles maintain levels of H2O, CO2, O2? ________________________ Water cycle & carbon cycle Other: .9% Ar, .1% other (including water vapor)

Atmospheric pressure (millibars) 200 400 600 800 1,000 120 75 200 400 600 800 1,000 120 75 110 Temperature Thermosphere 65 100 90 Mesopause 55 80 Mesosphere 45 70 Altitude (kilometers) Altitude (miles) 60 Stratopause 35 50 Stratosphere 40 25 Figure 18.3 Natural capital: The earth’s atmosphere is a dynamic system that includes four layers. The average temperature of the atmosphere varies with altitude (red line). Most UV radiation from the sun is absorbed by ozone (O3), found primarily in the stratosphere in the ozone layer 17–26 kilometers (10–16 miles) above sea level. Question: Why do you think the temperature falls and rises twice, going from lower to higher altitudes? 30 Tropopause 15 20 Ozone layer 10 Pressure Troposphere 5 (Sea level) Pressure = 1,000 millibars at ground level –80 –40 40 80 120 Temperature (˚C) Fig. 18-3, p. 470

Troposphere Stratosphere Mesosphere Thermosphere (including ionosphere) Exosphere

Describe Each Atmospheric Layer Composition Temperature Density variation why temperature change in layers of atmosphere

Click here Solar radiation Reflected by atmosphere Radiated by as heat UV radiation Lower Stratosphere (ozone layer) Most absorbed by ozone Troposphere Visible light Heat radiated by the earth Figure 3.8 Solar capital: flow of energy to and from the earth. See an animation based on this figure at CengageNOW. Heat Absorbed by the earth Greenhouse effect Fig. 3-8, p. 56

Heat Transfer at the Surface

Earth’s Energy Budget

Earth’s Energy Budget

Troposphere & Weather Troposphere is the weather maker Almost all clouds All precipitation All violent storms Discussed in Atmosphere Key Question 2