Chapter 7 - The Atmosphere Flashcards Preview

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Flashcards in Chapter 7 - The Atmosphere Deck (46):

Define: Chemoautotrophs

An organism that gains it's metabolic energy using energy from chemical reactions, e.g. nitrifying bacteria in the nitrogen cycle.


Define: Ozone

Triatomic oxygen


Define: Stratosphere

The layer of the atmosphere that absorbs UV and contains the ozone layer. It is above the troposphere at an altitude of approximately six to 30 miles.


Define: Dynamic Equilibrium

A combination of active processes that cancel out each other's effect so that there is no overall charge.


Define: Troposphere

The layer of the atmosphere below the stratosphere, from ground level to about six miles.


Define: Infrared (IR) Radiation

Long wavelength electromagnetic radiation emitted from warm objects.


Define: Nuclear Fusion

The release of energy during the joining of he nuclei of small atoms.


Define: Electromagnetic Radiation

Energy in the form of energy waves with a range of frequencies.


Define: Global Climate Change

The various changes to the climate caused by increased energy retained in the atmosphere as a result of human activities.


Define: Greenhouse Effect

The natural processes by which atmospheric gases allow visible light to pass through but absorb infrared energy, causing heating.


Define: Enhanced Greenhouse Effect

An alternative name for global climate change.


Define: Tropospheric Ozone

Ozone in the troposphere, largely produced by human activities.


Define: El Niño

The name given to the reversal of the equatorial Pacific Ocean current that normally flows westwards.


Define: La Niña

The name given to the strengthening of the westward flowing equatorial Pacific Ocean current.


Define: Positive Feedback Mechanism

A situation where an initial change causes a reaction that increases the original change.


Define: Negative Feedback Mechanism

A situation where an initial change causes a reaction that reduces the original change.


Define: Kyoto Protocol

The international agreement intended to control emissions of greenhouse gases.


Define: HFCs

Hydrofluorocarbons are a group of chemicals used to replace CFCs.


Define: HCFCs

Hydrochlorofluorocarbons are a group of chemicals used to replace CFCs.


Define: MEDC

More Economically Developed Countries.


Define: Anthropogenic

Something made or caused by human activities.


Define: CFCs

Chlorofluorocarbons are pollutants that cause ozone depletion and contribute to global climate change.


Define: Infiltration

The process by which surface water enters the ground between the particles of soil or rock.


Define: Montreal Protocol

International agreement that has controlled the release of ozone-depleting substances.


What are the gases of the atmosphere, including proportion and importance for life?

- Nitrogen (78%) [Used in proteins]
- Oxygen (21%) [Used in aerobic respiration]
- Carbon Dioxide (0.038%) [Used in photosynthesis]
- Rare Gases (1%)
- Methane (0.00017%) [Chemoautotrophs use methane as carbon]
- Ozone (0.000007%) [Absorbs UV light in stratosphere]
- Water Vapour (Variable) [water in the water cycle]


What are the major anthropogenic sources of greenhouse gases?

- Carbon Dioxide (Combustion of fossil fuels, deforestation)
- Methane (Landfill sites, livestock intestines, pipeline leaks)
- Nitrogen Oxides (Power stations, vehicle engines)
- CFCs (Aerosol propellants, fire extinguishers, refrigerants)
- Tropospheric Ozone (Photochemical breakdown of NO2)


What are the likely consequences of global climate change?

- Sea level rise
> Thermal Expansion (sea warms up and expands)
> Melting land ice (flows into sea, increases volume)
- Changes in climate
> Wind patterns (change in velocity, direction, frequency)
> Precipitation (increased evaporation rates)
- Ocean current changes
> El Niño (reversal of Equatorial Pacific Ocean current)
> La Niña (normal Equatorial Pacific Ocean current strengthened)
> North Atlantic Conveyor (Greenland land ice melting)
- Ecological changes
> Faster plant growth
> Shallow rooted plants cope less well
> Hibernating species disturbed frequently
> Wetland habitats enlarged/shrunk
> Ecological events changed (migration, flowering)


What are the changes in currents in an El Niño year?

- Wind direction reversed (eastwards, Australia to South America)
- Ocean current reversed (water warms up and is carried east)
- Colder Australian water (dry season, little rainfall, droughts)
- Warmer South American water (increased evaporation, heavy rains and floods)


How does global climate change affect the North Atlantic Conveyor?

- Melting Greenland icecap (increased melt water)
- Reduced return current
- Cooled seawater diluted by freshwater (melting ice)
- Smaller density increase (less sinking of water)
- Europe becomes colder


Why is it difficult to predict global climate change accurately?

- Natural changes (difficult to tell if humans caused it)
- Limited historical data (rainfall patterns, wind velocity)
- Natural processes interconnected (unexpected effects)
- Very slow changes (sea level rise)
- Changes in different locations/times
- Do not fully understand Earth's climate systems


What would raised temperatures cause?

- Increased decomposition rates (more carbon dioxide released)
- Reduced albedo (smaller area of ice/snow)
- Methane released from methane hydrate in methane sediments
- Melting permafrost release methane gas bubbles
- Drier forests (fires more frequent, extra carbon dioxide)


What are the methods of reducing Carbon Dioxide levels?

- Energy conservation to reduce use of fossil fuels.
- Use of alternative energy resources.
- Carbon sequestration by planting more trees.
- Storage of CO2 from power stations underground.
- Kyoto Protocol emission reductions.


What are the methods of reducing Methane levels?

- Reduced dumping of waste in landfill sites.
- Reduced livestock production.
- Better collection of gas from coal mines and gas and oil facilities.


What are the methods of reducing Nitrogen Oxides levels?

- Reduced use of internal combustion e.g. more use of public transport.
- Catalytic converters in vehicle exhausts.
- Addition of urea to power station effluents.


What are the methods of reducing Chlorofluorocarbons levels?

- Use of alternative methods:
> Butane or propane in aerosol cans.
> HFCs and HCFCs in refrigerators.
> Alcohols as solvents for cleaning equipment.
- Use of alternative processes:
> Trigger and pump action spray cleaners.
> Stick deodorants.


What are the methods of reducing Tropospheric Ozone levels?

- Same as Nitrogen Oxides methods.


How can agricultural strategies been out into place to cope with climate change?

- Cultivate warmer climate crops
- Cultivate drought-resistant crops
- Abandon unsustainable irrigation areas.
- Increase soil organic matter to increase water retention
- Water storage in times of water surplus for irrigation use


How can building design strategies be put into to place to cope with global climate change?

- Better ventilation/cooling systems (reduce air conditioning)
- Paler materials (reduce heat absorption)


Why is there concern about ozone depletion?

- UV B reach Earth's surface (absorbed by living cells)
- DNA damage
- Skin cancer
- Cataracts
- Plant tissue damage


How can flooding strategies be put into place to cope with climate change?

- Riverbank defences
- River barrages (protect against high tides)
- Less building on flood plains
- Reduce runoff rates (reduced paved areas increase infiltration)
- River regulation dams


How can coastal erosion strategies be put into place to cope with climate change?

- Improved coastal defences
- Managed retreat (abandon lower value areas)


How can storm damage strategies be put into place to cope with climate change?

- Stronger building design


What are the categories of UV light and their characteristics?

- UV A (Not absorbed by ozone)
- UV B (Almost fully absorbed by ozone)
- UV C (Completely absorbed by ozone)


What are the reactions involved in ozone depletion by chlorine?

1) Cl + O3 ---> ClO + O2
2) ClO + O ---> ClO2
3) ClO2 ---> Cl + O2

Summary Reaction) Cl + O3 + O ---> 2O2 + Cl


Why is ozone depletion greatest in Polar Regions?

- Reaction occurs in low temperatures
- Ice crystals provide catalytic surfaces
- Spring time, sunlight causes reaction


Do other gases cause ozone depletion?

- Nitrogen oxides
- Released in troposphere, dissolved into rain