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.