Atmosphere and Air Quality Quiz

Chapter 8: Air: What Are We Breathing?

• This chapter discusses the composition, circulation, pollution, and policies related to Earth's atmosphere.

Chapter Outline

• 8.1 What Makes Up the Air We Breathe and Our Atmosphere?
• 8.2 What Is Weather and How Does It Change?
• 8.3 How Does the Atmosphere Circulate?
• 8.4 How Does the Atmosphere Become Polluted?
• 8.5 What Is Happening to the Ozone Layer?
• 8.6 What Is Acid Rain?
• 8.7 How Are We Responding to Pollution in the Atmosphere?
• 8.8 What Can I Do?

Chapter Objectives

• Name the most prominent gases in the atmosphere.
• Describe the four layers of Earth's atmosphere.
• Explain how air masses move, relating to temperature, moisture, and wind.
• Define primary and secondary pollutants and provide examples.
• Explain how secondary pollutants cause smog, ozone layer depletion, and acid rain.
• Compare and contrast policies aimed at improving air quality.

Air, I should explain, becomes wind when it is agitated. —Lucretius, 50 BCE

• Air, a dynamic gaseous envelope, clings to Earth due to gravity, extending up to 62 miles.
• Automobiles are a major source of air pollution, releasing CO, particulate matter (PM), and nitrogen oxides (NOx).

8.1 What Makes Up the Air We Breathe and Our Atmosphere?

• Earth's atmosphere is a mixture of gases.
• The gases are mostly nitrogen (78%), oxygen (20%), argon, carbon dioxide, water vapor, and other trace compounds.
• These atoms and molecules continuously move within the atmosphere.

Pressure (1 of 2)

• Pressure is the force exerted on something.
• Adding air, compressing, or raising the temperature of the air in a closed container increases the pressure.
• All gases move from areas of high pressure to areas of low pressure.

Pressure (2 of 2)

• Imagine a column of air extending high above Earth's surface.
• The weight of the air above exerts pressure downwards, increasing this pressure.
• As air moves higher, the pressure becomes thinner.

How Is Earth's Atmosphere Structured? (1 of 2)

• Earth's atmosphere is divided into four layers: troposphere, stratosphere, mesosphere, thermosphere.
• The troposphere, about 5-10 miles thick, contains most of the atmosphere's mass.
• The stratosphere extends about 30 miles above the troposphere and contains the ozone layer.

How Is Earth's Atmosphere Structured? (2 of 2)

• The mesosphere lies above the stratosphere and has cold temperatures, reaching as low as -148°F.
• The thermosphere is warmer due to solar and cosmic radiation and less dense due to lower levels of gravity.

8.2 What Is Weather and How Does It Change?

• Weather refers to short-term conditions (temperature, moisture, wind) in a specific place
• Climate is the long-term average of weather conditions in a region.
• The National Weather Service defines climate as a 30-year average of regional weather conditions.
• Climate is what you expect, weather is what you get.

Temperature

• Temperature is a measure of hotness or coldness using a thermometer.
• Solar radiation warms Earth.
• The amount of radiation received varies by latitude, hence temperature variations.
• Land and water features affect temperature variations.

The Unexpected Consequences of Severe Weather

• Drought can stress trees, making them susceptible to insects, diseases, and death.
• Scientists are monitoring trees' vulnerability to climate change.

Water Vapor

• Precipitation, humidity, and cloud cover reflect the amount of water vapor in the air.
• Water vapor evaporates and condenses in the atmosphere, affecting evaporation rates.
• Relative humidity is the percentage of water vapor in the air, compared to the maximum possible at a given temperature.

Barometric Pressure (1 of 2)

• Meteorologists discuss high-and low-pressure systems.
• Barometric pressure is a measure of the Earth's atmospheric pressure at a given point.
• Temperature and pressure cause changes in air masses, which are large volumes of air.

Barometric Pressure (2 of 2)

• High-pressure systems result from cooler, denser air that sinks.
• When air masses warm, the molecules expand, creating a low-pressure system.
• Rising warm air draws in more air, whereas cold air sinks.

Wind, Fronts, and Storms

• Air motion from high to low pressure is wind.
• A cold air mass replacing a warm is a cold front, a warm air mass replacing a cold is a warm front..
• Fronts form at boundaries between high and low-pressure systems.
• Extreme weather conditions (low-pressure systems) can create hurricanes and typhoons.

Lake and Land Effects

• Interior regions receive less precipitation than coastal areas because they are farther from the ocean.
• Large bodies of water (e.g., Great Lakes) affect weather changes during cold winds.
• The topography of mountains affects weather by forcing rising air masses to release their moisture.

8.3 How Does the Atmosphere Circulate?

• Global air circulation patterns are driven by Earth's rotation and temperature differences between the equator and the poles.
• Atmospheric pressure and prevailing winds circulate particles.

Patterns of Atmospheric Pressure and Prevailing Winds (1 of 3)

• The equator receives direct sunlight, causing rapid evaporation and rising warm humid air.
• This equatorial low-pressure belt causes high precipitation in tropical rainforests.
• Warm air rises and cools, spreading north and south, creating subtropical high-pressure belts.

Patterns of Atmospheric Pressure and Prevailing Winds (2 of 3)

• Subtropical high-pressure belts cause arid conditions in certain regions (e.g. Sahara Desert).
• Air circulates through looping patterns.
• Hadley cells are circulation systems between the equator and latitudes 30°N and 30°S.

Patterns of Atmospheric Pressure and Prevailing Winds (3 of 3)

• The Coriolis effect influences wind patterns.
• Wind deviates in the Northern and Southern hemispheres.
• Jet streams form at altitudes above Earth's surface, affecting wind patterns.

Atmospheric Dust Transport

• Air circulation patterns carry particles like dust, soot, and ash.
• Wind and weather conditions sweep up particles, moving them over long distances (e.g., to Greenland).
• Desert dust can affect vegetation and trees.

8.4 How Does the Atmosphere Become Polluted?

• Air pollution occurs when materials added to the atmosphere harm human and other organisms.
• Pollution comes from sources such as wood/fuel burning emissions, and other pollutants.
• Atmospheric conditions and circulation affect pollution effects.

Primary Pollutants (1 of 3)

• A primary pollutant is a substance that is harmful in its emitted form.
• Carbon Monoxide (CO) is a prevalent primary pollutant (Incomplete Fuel Combustion)
• Other primary pollutants include Pesticides in agriculture, Benzene from gasoline and Asbestos from construction activities.

Primary Pollutants (2 of 3)

• Particulate Matter (PM) are tiny particles or droplets that are suspended in air and can cause respiratory problems.
• The smaller the PM particles, the more dangerous they are as they can enter the bloodstream easily.

Primary Pollutants (3 of 3)

• Toxic metals like lead, mercury, and arsenic, can travel in air, accumulate in bodies, and lead to health issues, such as delays in mental and physical development, and kidney damage.
• Volatile Organic Compounds (VOCs) come from fossil fuel combustion and other sources (e.g., paints, solvents).
• Higher concentrations of VOCs are often seen indoors.

Secondary Pollutants (1 of 2)

• Secondary pollutants are products of reactions among primary pollutants and with sunlight and other atmospheric components.
• Smog is a mixture of secondary pollutants formed from the interactions of VOCs and nitrogen oxides (NOx) with sunlight.

Secondary Pollutants (2 of 2)

• Thermal inversions occur when a layer of warm air traps pollutants near Earth, preventing air circulation.
• This leads to high concentrations of air pollution over a surface area.

8.5 What Is Happening to the Ozone Layer? (1 of 3)

• Stratospheric ozone protects terrestrial life from UV radiation.
• Ozone (O3) forms when oxygen (O2) reacts with ultraviolet (UV) light.
• Ozone sustains itself by splitting oxygen into oxygen atoms, and then merging again with an oxygen gas molecule to re-form an ozone molecule.

What Is Happening to the Ozone Layer? (2 of 3)

• Chlorofluorocarbons (CFCs) were found to deplete the ozone layer by reacting with stratospheric ozone.
• Chlorine atoms released from CFCs react with ozone, destroying it.

What Is Happening to the Ozone Layer? (3 of 3)

• Satellite images showed a steady decline in stratospheric ozone during the 1970s and 1980s.
• The ozone hole over Antarctica is an area of severe ozone depletion.
• Increased UV radiation due to ozone depletion has consequences, such as higher incidences of skin cancer and cataracts.

8.6 What Is Acid Rain? (1 of 2)

• Normal rainwater is slightly acidic (pH of 5.6).
• Sulfur dioxide (SO2) and nitrogen oxides (NOx) emitted from human sources react with atmospheric water vapor to produce sulfuric acid (H2SO4) and nitric acid (HNO3) resulting in acid rain.

What Is Acid Rain? (2 of 2)

• Acid deposition from these reactions has changed the pH levels in lakes and altered the ecology.
• Acid precipitation affects soil pH and important soil microbes affecting plant growth and mortality.
• Acid deposition also harms buildings, statues, and other structures made of limestone and marble.

8.7 How Are We Responding to Pollution in the Atmosphere? (1 of 3)

• Policy strategies to address air pollution have reduced pollutants.
• The Clean Air Act (1970) uses air quality standards and regulations for pollutant sources to address air pollution effectively.
• There have been improvements in air quality, but pollution levels remain a concern.

8.7 How Are We Responding to Pollution in the Atmosphere? (2 of 3)

• The Energy Policy and Conservation Act (1975) established corporate average fuel economy (CAFE) standards to improve automotive fuel efficiency and thus lower emission levels.

8.7 How Are We Responding to Pollution in the Atmosphere? (3 of 3)

• The Clean Air Act (1990) created cap-and-trade policies allowing utilities to trade allowances for emissions, helping incentivize emission reductions.

8.8 What Can I Do?

• Choose transportation wisely, cutting down on idling and running cars improperly.
• Limit at-home and campus pollution by managing thermostat settings and using energy-efficient appliances.
• Explore new technologies such as moss in urban settings to remove particulate matter and greenhouse gases.
• Learn more about local power generation policies to affect political change.

Question 1

• What gas composes the largest portion of Earth's atmosphere?
• Answer: Nitrogen

Question 2

• Ozone in the atmosphere is important for absorbing and scattering much of the UV radiation coming into Earth's atmosphere from the sun. Which layer is ozone found in?
• Answer: Stratosphere

Question 3

• Typical patterns of atmospheric conditions in a specific location over years, decades, and larger time periods are described by what?
• Answer: Climate

Question 4

• Morning commutes in urban areas can result in which type of secondary air pollution?
• Answer: Smog

Question 5

• Which of the following is a successful market-driven mechanism for addressing air pollution in the United States?
• Answer: Cap-and-trade

Test your knowledge on the layers of the atmosphere, the effects of air pollution, and the importance of climate and weather. This quiz covers topics such as ozone depletion, the Clean Air Act, and the relationship between pollutants and their sources. Challenge yourself to see how well you understand these environmental concepts.