Lecture 2 Flashcards
Atmospheric Composition
- Nitrogen 78.08%
- Oxygen 20.95%
- Argon 0.93%
- Carbon dioxide 0.04%
Ecosystem services
- Blocks UV radiation
- Moderates the climate
- Redistributes water in the hydrologic cycle
Air Pollution:
Chemicals added to the atmosphere by natural events or human activities in high enough
concentrations to be harmful
Primary Air Pollutant
Harmful substance that is emitted directly into the atmosphere
Secondary Air Pollutant
Harmful substance formed in the atmosphere when a primary air pollutant reacts with substances normally found in the atmosphere or with other air pollutants
Primary Pollutants
• particulate matter (PM) nitrogen oxides carbon monoxide sulfur dioxide . volatile organic compounds (VOCs) . lead.
What They Are
- Carbon Monoxide 49.1%
- Sulfur Oxides 16.4%
- Nitrogen Oxides 14.8%
- Volatille Organics 13.6%
- Particulates 6%
What They Come From
- Transportation 46.2%
- Stationary Source Fuel Combustion 27.3%
- Industrial Process 15.0%
- Miscellaneus 9% , Solid waste 2.5%
Sources of Primary Pollutants
By humans:
- Combustion
- Chemical
- Nuclear or Atomic
- Roasting, Heating, Refining
- Mining, Quarrying, Farming
Sources of Primary Pollutants Natural
- Volcanoes
- Breaking Seas
- Pollens
- Fire
- Blowing Dust
- Bacteria, Viruses
one example of a secondary pollutant
• Atmospheric sulfuric acid
Smog
Air pollution in urban and industrial areas
Photochemical smog
A noxious mixture of gases and particles, is produced when strong sunlight triggers photochemical reactions in the atmosphere
Brownish-orange haze formed by chemical reactions
involving sunlight, nitrogen oxide, and hydrocarbons
Ozone
The major component of photochemical smog
Major Classes of Air Pollutants
- Particulate Material
- Nitrogen Oxides
- Sulfur Oxides
- Carbon Oxides
- Hydrocarbons
- Ozone
Thousands of different solid or liquid particles suspended in air
• Dangerous for 2 reasons
-May contain materials with toxic or carcinogenic effects
-Extremely small particles can become lodged in lungs
Particulate Material
Nitrogen Oxides
Gases produced by the chemical interactions between atmospheric nitrogen and oxygen at high temperature
Nitrogen Oxides and its problems
Gases produced by the chemical interactions between atmospheric nitrogen and oxygen at high temperature
Greenhouse gases
Cause difficulty breathing
Sulfur OxidesGases
Produced by the chemical interactions between sulfur and oxygen
Causes acid precipitation
Carbon Oxides
Gases carbon monoxide (CO) and carbon dioxide (CO2)
Greenhouse gases
Hydrocarbons
Diverse group of organic compounds that contain only hydrogen and carbon (ex: CH4-methane)
Hydrocarbons
Diverse group of organic compounds that contain only hydrogen and carbon (ex: CH4-methane)
Some are related to photochemical smog and greenhouse gases
Man- made pollutant in the lower atmosphere
Secondary air pollutant
Component of photochemical smog
Tropospheric Ozone
Essential component that screens out UV radiation in the upper atmosphere
Stratospheric Ozone
Transportation
Industry
Two main Sources of Outdoor Air Pollution
Intentional forest fires
Sources of Outdoor Air Pollution
Air Pollution Effects
Irritates eyes
Causes inflammation of respiratory tract
Can develop into chronic respiratory
diseases
Sulfur Dioxide and Particulate material
Irritate respiratory tract
Impair ability of lungs to exchange gases
Causes airway restriction
Nitrogen Dioxides
Binds with iron in blood hemoglobin
Causes headache, fatigue, drowsiness, death
Carbon monoxide
Ozone
Causes burning eyes, coughing, and chest
discomfort
Smokestacks with
electrostatic precipitator
Particulate material can
also be controlled by
proper excavating
techniques
Phase I Vapor Recovery System for
gasoline
Controlling Air Pollution
Reduce sulfur content in gasoline from its current average of 330 ppm to 30 ppm
Sulfur clogs catalytic converters
Require legal emission standards for all passenger vehicles
Including SUVs, trucks and minivans
Require emission testing for all vehicles
Including diesel
Other Ways to Improve Air Quality
Ozone Protects earth from UV radiation
Part of the electromagnetic spectrum with
wavelengths just shorter than visible light
Ozone thinning/hole First identified in 1985 over Antarctica Caused by human-produced bromine and chlorine containing chemicals
Ozone Depletion in Stratosphere
Higher levels of UV-radiation hitting the earth
Eye cataracts
Skin cancer
Weakened immunity
May disrupt
ecosystems
May damage crops
and forests
Effects of Ozone Depletion
Recovery of Ozone Layer
Montreal Protocol (1987)
Reduction of CFCs
Started using HCFCs (greenhouse gas)
Phase out of all ozone destroying chemicals
is underway globally
mixing depth
The vertical distance between Earth’s surface and
the height to which convectional movements extend is
called the
Mixing depth
The vertical distance between Earth’s surface and
the height to which convectional movements extend
Represent a situation in which the atmosphere is very stable and the mixing depth is significantly restricted.
Temperature inversions
Temperature inversions
Represent a situation in which the atmosphere is very stable and the mixing depth is significantly restricted.
Form because the ground is a more effective radiator than the air above
Surface temperature inversions
Surface temperature inversions
Form because the ground is a more effective radiator than the air above
Are associated with sinking air that characterizes centers of high air pressure (anticyclones).
Inversions aloft
Inversions aloft
Are associated with sinking air that characterizes centers of high air pressure (anticyclones).
