APES LAP 4
Ammonium sulfate
(NH4)2SO4
Stratosphere
- 11-50 km (7-31 mi) above sea level - Drier and less dense, with little vertical mixing - Colder in its lower regions (temperature increases with altitude - Contains UV radiation-blocking ozone/ "ozone-layer", 17-30 km (10-19 mi) above sea level - Ozone layer is in the stratosphere
Mesosphere
- 50-80 km (31-56 mi) above sea level - Extremely low air pressure - Temperatures decreases with altitude
Low-pressure system
- Air moves toward the low atmospheric pressure at the center of the system and spirals upward - Clouds and precipitation
Convective circulation
- Air near Earth's surface is warmer and moister than air at higher latitudes - Warmer air rises (becomes less dense) and creates vertical currents - Rising air expands and cools - Cool air descends and becomes denser (brings moisture), replacing warm air - Influences both weather and climate
High-pressure system
- Air that moves away from a center of high pressure as it descends - Brings fair weather
Thermosphere
- Atmosphere's top layer - Very thin air - Mostly lightweight elements - Very hot - Ionic radiation (where aurora borealis takes place) - Extends upward to 500 m (300 mi)
Solar energy creates seasons
- Because the Earth is titled - Each hemisphere tilts toward the sun for half of the year - Results in a change of seasons - Equatorial regions are unaffected by this tilt, so days average 12 hours through the year (contrasts with the poles)
Trade winds
- Between the equator and 30 degrees latitude - Blow from east to west
Troposphere
- Bottommost layer; at Earth's surface (11km high) - Air for breathing, weather - Temperature declines with altitude - Tropopause = limits mixing between troposphere and the layer above it
Hazardous atmosphere
- Contains a toxic chemical above PEL (permissible exposure limit) - Has less than 19.5% oxygen - Contains a combustible gas within its explosive limit
Primary pollutants
- Directly harmful and can react to form harmful substances - Soot and carbon dioxide, methane
Wind patterns
- Doldrums, trade winds, westerlies - People used these winds to sail their ships across the ocean
Secondary pollutants
- Form when primary pollutants interact or react with constituents or components of the atmosphere (can be worse than primary) - Tropospheric ozone and sulfuric acid
Westerlies
- From 30 to 60 degrees latitude - Originate from the west and blow east
Air pollutants
- Gases and particulate material added to the atmosphere - Can affect climate or harm people - Air pollution is the release of pollutants
Ferrel cells and polar cells
- Lift air - Creates precipitation at 60 degrees latitude north and south - Causes air to descend at 30 degrees latitude
Case Study: London
- London has had bad air pollution for centuries that has killed thousands (industrial) - Today, smog from traffic is a problem (photochemical) - The "congestion-charging" program charges drivers to drive into central London during the week - Congestion decreased, fewer accidents occurred and the air became cleaner
Air pollution
- Material added to the atmosphere that can affect climate and harm organisms, including humans - Natural or anthropogenic release directly into air - Government policy and improved technologies have helped diminish outdoor or ambient air pollution substantially in developed but not developing countries. - Can be point source (like a smokestack) or non-point source (traffic)
Atmospheric pressure
- Measures the force per unit area produced by a column of air - Decreases with altitude
Nonpoint sources
- More diffuse, consisting of many small Sources - Automobiles; charcoal fires from thousands of homes (anthropogenic source)
Doldrums
- Near the equator (few winds)
Hadley cells
- Near the equator, surface air warms, rises, and expands - Releases moisture and heavy rainfall near the equator
Mechanisms of breathing
- Nose, Nasal Passages, Nasal Pharynx - Mouth, Pharynx - Larynx, Trachea - Bronchi, Bronchiolus - Air Sacs - Alveoli - Muscles Air pollution can cause elasticity of the lungs
Ozone layer (stratosphere)
- Not really a layer, but a region of higher-than-normal ozone concentrations (which are still very low) - Absorbs ultraviolet (UV) radiation from sun, protecting organisms on surface from radiation damage - Any ozone found in troposphere is from burning of fossil fuels and is considered a pollutant- respiratory irritant - Good up high (stratosphere), bad down low (troposphere)
Point sources
- Specific spots where large quantities of pollutants are discharged - Power plants and factories (anthropogenic source)
Front
- The boundary between air masses that differ in temperature, moisture, and density - Warm or cold
Coriolis effect
- The north-south air currents of the convective cells appear to be deflected from a straight path - Results in curving global wind patterns
Relative humidity
- The ratio of water vapor a given volume of air contains the amount it could contain at a given temperature
Solar energy heats the atmosphere
- The spatial relationship between the Earth and sun determines the amount of solar energy striking the Earth - Energy from the sun: heats air, moves air, creates seasons, influences weather and climate - Solar radiation is highest near the equator - When UV rays hit the earth's surface - about 70% absorbed by atmosphere and 30% goes back into space
Atmosphere
- The thin layer of gases that surrounds Earth - Absorbs radiation (stratosphere) - Burns up meteors (mesosphere) - Moderates climate (troposphere) - Transports and recycles water and nutrients (troposphere) - 78% nitrogen gas, 21% oxygen gas, 1% other gases - Its four layers differ in temperature, density and composition - Minute concentrations of permanent (remain at stable concentrations) and variable gases (varying concentrations) - Human activity is changing the amounts of some gases
Temperature
- Varies with location and time - Sun's rays strike more of Earth's surface at different areas
El Nino and La Nina (ENSO)
- normal trade wind patterns blow from east to west and bring cold nutrient-rich water along the west coast of south America causing upwelling of nutrients -El nino stalls this event by causing trade winds to reverse in the opposite direction and become like the westerlies (west to east) -la nina amplifies this event by strengthening the east to west trade winds
How does the angle at which the sun hits the earth affect the energy released?
-at the equator, the sun hits earth with a 90 degree angle meaning that there is MORE energy given to each unit of earth's surface area making it warmest here-at higher and lower latitudes, the sun hits earth with a greater degree (likely 30-60 degrees up or down), which means that there is LESS energy given to each unit of earth's surface area-at the highest and lowest latitudes (aka the poles), the sun hits earth with an extremely low angle (nearly 0 degrees) which means that the poles receive the least solar energy per unit area, making them very cold
Natural sources of air pollution
1. Dust storms (due to deforestation) 2. Volcanoes (release SO2) 3. Fires
Recap on layers of atmosphere
1. Region where the protective ozone layer is located = stratosphere 2. Region that contains the majority of molecules in the atmosphere = troposphere 3. Region largely responsible for the weather experienced at the Earth's surface = troposphere 4. Region most affected by the greenhouse effect = troposphere
PPT 2
Air Pollution
Volcanism
Any activity that includes the movement of magma toward or onto Earth's surface - Natural source of air pollution - Can actually blanket the surface and create a cooling effect of the atmosphere
Argon
Ar
PPT 1
Atmosphere & Air
Hindenburg disaster
Blimp blew up (helium very combustible)
CFC (Chlorofluorocarbon)
CCl₃F
Methane
CH4
Carbon monoxide
CO
Carbon dioxide
CO2
Megacity
City with a population of 10 million or more people - about 34 (maybe)
Chloride
Cl-
Hydrocarbons
Compounds composed of only carbon and hydrogen (C_H_)
Climate
Describes patterns of atmospheric conditions across large geographic regions over long periods of time (AKA a year) - Mark Twain said "Climate is what we expect; weather is what we get"
What is the biggest threat to our atmosphere?
Greenhouse gases
Carbonic acid
H2CO3
Hydrogen peroxide
H2O2
Hydrogen sulfide
H2S
Sulfuric acid
H2SO4
Hydrochlorofluorocarbons
HCFCs
Nitrous acid
HNO2
Nitric acid
HNO3
Killer Fog of London
Industrial smog in the 1950s in London
Atomic nitrogen
N
Atmospheric nitrogen
N2
Nitrous oxide
N2O
Ammonia
NH3
Ammonium
NH4+
Nitric oxide
NO
Nitrogen dioxide
NO2
Nitrite
NO2-
Nitrate
NO3-
Nitrogen Oxides (NOx)
NOx
What is the makeup of air?
Nitrogen: 78% Oxygen: 20.9% Argon: 0.9% Carbon Dioxide: 0.03% Methane: 0.0002%
How long does it take for air to circulate the world?
Not fully known + depends on season - Usually around 10-35 days
Nitrogen compounds
N₂ = molecular nitrogen NO= nitric oxide N₂O= nitrous oxide NO₂ = nitrogen dioxide NO₂ ‾ = nitrite NO₃¯ = nitrate HNO₃ = nitric acid HNO₂ = nitrous acid NH₃ = ammonia NH₄+ = ammonium PAN = peroxyacl nitrate
Atomic oxygen
O
Molecular oxygen
O2
Ozone
O3
Peroxyacl Nitrates
PANs
Permissible exposure limit
PEL; the maximum legal limits established by OSHA for regulated substances; these are based on employee exposure that are time-weighted over an 8 hour work shift; when these limits are exceeded, employers must take proper steps to reduce employee exposure; for formaldehyde, the PEL is .75 ppm
Particulate matter
PM
Lead
Pb
Sulfur dioxide
SO2
Sulphur trioxide
SO3
Sulphate
SO4 2-
Primary pollutants - Carbon monoxide From incomplete combustion of fossil fuels Ex. From cars We have a higher affinity for carbon monoxide than oxygen, but it is toxic for us - Carbon dioxide - Unburned hydrocarbons - Nitrogen oxides Especially nitrogen dioxide (a brown gas), also nitrous oxide and nitric oxide Brown appearance - Sulfur dioxide From coal with high Sulphur content Or naturally from volcanism - PM (particulate matter) Ex: carbon, soot Greater than 2.5 = concerning - Building sites, forest fires
Secondary Pollutants - Photochemical reactions - Tropospheric ozone - Particulates produced from gaseous primary pollutants -Peroxyacl nitrate (PAN)
Indicator species
Species that serve as early warnings that a community or ecosystem is being degraded. - For air pollution, lichen is an indicator species - Mutualistic relationship between algae and fungi (algae provides oxygen and glucose for the fungus to decompose; photosynthesis and cellular respiration happening together) - Lichen absorbs everything in the air - Lichen will not grow in an environment that is high in SO2 - After Chernobyl, more than 70,000 reindeer had to be killed because they ate highly radioactive lichens and humans ate the deer (biomagnification) - Because lichens are widespread, long-lived, and anchored in place, they can help track pollution to its source.
Weather
Specifies atmospheric conditions over short time periods and within a small geographic areas (day-to-day basis)
Purpose of the MILAGRO Project
Study air pollution in Mexico
Tropopause
The boundary between the troposphere and the stratosphere. - Layers don't mix
Cold front
The boundary where colder, drier air displaces warmer, moister air
Warm front
The boundary where warm moist air replaces colder, drier air
What is the boundary layer of the atmosphere?
The lowest part of the troposphere that is directly influenced by the presence of the earth's surface, and responds to surface forcing within a timescale of about an hour or less
Exosphere
The outer layer of the atmosphere, extending outward into space.
Atmosphere's 4 Layers
Troposphere Stratosphere Mesosphere Thermosphere Exosphere (outer space) - Higher you go up, less dense - Lower pressure at higher altitudes
Volatile organic compound
VOCs
Ozone layer
a layer in the stratosphere (at approximately 20 miles) that contains a concentration of ozone sufficient to block most ultraviolet radiation from the sun - Protective layer in atmosphere that shields earth from UV radiation.
Atmospheric cells
air warmed by the intense tropical heat would rise and flow northward to the poles, it would then cool and return southward to the equator - Hadley, Ferrel, Polar - Interact with the Earth's rotation to produce global wind patterns - As Earth rotates, equatorial regions spin faster
Convective currents...
contribute to climatic patterns and affect moisture distribution
What gases come from cars?
nitrogen dioxide, carbon monoxide, hydrocarbons, benzene, and formaldehyde
Air circulates leading to...
proliferation of air pollution
Albedo
the percentage of incoming sunlight reflected from a surface - Water has a high albedo (greater ability of a surface to reflect light) vs pavement (low albedo - absorbs heat)
Atmospheric concentration
•78% nitrogen •21% oxygen •1% argon •traces of other permanent gases and variable small amounts of: •Water vapor (GHG - but not anthropogenically caused - through the water cycle) •Carbon dioxide •Methane •pollutants •etc.