Atmosphere Flashcards
What is the composition of the atmosphere?
78% nitrogen 21% oxygen 0.04% carbon dioxide
What is the order of the layers of the atmosphere?
(The silly monkeys twirled endlessly)
Troposphere, Tropopause, Stratosphere, Stratopause, Mesosphere, Mesopause, Thermosphere, Exosphere
Why does the temperature increase with altitude up to 48km?
Most ozone is contained in the stratosphere and UV light interacting with the ozone causes temperature increase.
What happens to the temperature above the stratopause and in the mesosphere?
It decreases due to altitude increase.
What happens to temperature in the thermosphere?
Temperature increases with height.
What happens in the exosphere?
Molecules have enough kinetic energy to escape Earth’s gravity and fly off into space.
Why does atmospheric CO2 concentration fluctuate throughout the year?
In the summer, more photosynthesis can take place so CO2 is reduced.
What two major processes maintain the dynamic equilibrium in the atmosphere?
Photosynthesis and aerobic respiration.
How does the sun release energy?
Nuclear fusion whereby hydrogen nuclei collide under extreme heat and pressure in the interior of the sun to make helium nuclei, releasing lots of energy.
Why does the moon have no atmosphere?
It has a low mass, meaning less gravity and no atmosphere because particles can escape easier.
What happens when UV hits ozone ?
The ozone (O3) permanently absorbs the UV and splits it into O and O2.
Why is UV dangerous for life?
It can cause damage to cells
In what ways is the atmosphere heated?
- Visible light is transmitted through the atmosphere and absorbed by the Earth’s surface.
- The radiation is re emitted as IR.
- GG absorb and re-emit the IR, warming the atmosphere.
What is meant by temperature?
A representation of the average energy of particles in a system.
How doe the atmosphere support life? (6)
- Gases for natural processes e.g. carbon, oxygen
- Absorbs electromagnetic radiation from the Sun.
- Delays the escape of IR and warms the Earth.
- Distributes heat.
- Creates ocean currents.
- Transports water vapour for precipitation in areas.
What are anthropogenic sources of CO2, CH4, NOx, CFCs and tropospheric ozone contributing the to EGE?
CO2 - combustion of fossil fuels, agriculture
CH4 - agriculture
NOx - vehicle engines, power stations, fertiliser use
CFCs - refrigeration, aerosol propellants
Tropospheric ozone - cars, power plants
What factors determine the impact a GG has on global warming? (3)
- Concentration in atmosphere
- Residence time
- How relatively powerful it is
Where can the ozone layer be found?
In the stratosphere
Why is the ozone layer important?
Provides a protection barrier between Earth’s surface and the Suns UV radiation.
How did CFCs cause a breakdown of the ozone layer?
CFCs absorb UV which causes the release of a chlorine free radical. The radical reacts with monatomic oxygen. The lack of monatomic oxygen in the atmosphere means ozone cannot form.
What was the Rowland-Molina hypothesis?
Releasing CFCs into the atmosphere will cause significant ozone depletion due to the chemical properties of CFCs.
Who were Rowland and Molina inspired by?
James Lovelock
What did Rowland and Molina use to check on ozone levels?
High altitude balloons carrying sensitive measuring devices.
How does the persistence of CFCs lead to ozone depletion?
CFCs are chemically stable so remain in the atmosphere long enough to be carried to the stratosphere.
What was the Montreal Protocol and when was it signed?
An agreement signed by 93 countries in 1990 agreeing to phase out CFCs by 2000s.
Why was ozone depletion most severe over Antarctica?
Stratospheric temperatures over Antarctic are lower than anywhere else allowing the formation of stratospheric clouds and ice crystals.These provide surfaces for chemical reactions to take place - chlorine molecules from the chlorine released by CFCs are formed.
Winds around Antarctica form a polar vortex which maintains low temperatures and produces higher concentrations of the chlorine that forms on the ice crystals.
How can global climate change cause ecological changes?
A change in abiotic factors can affect habitats e.g. wetland habitats may become larger, the timing of ecological events such as flowering, migration and nesting can change, the distribution of species may change.
Explain the positive feedback loop of high temperatures reducing ice cover.
Higher global temperatures reduce the amount of snow and ice and the time it remains on the surface before melting. This increases the albedo so more sunlight is absorbed by the Earth’s surface causing further heating.
How can global climate change cause changes in the cryosphere?
- Reductions in the amount and duration of snow cover.
- Changes to the extent and speed of movement of land ice (shrinking glaciers)
- Loss of ice shelves
- Changes in ice thickness and area
- Melting ice lakes can cause flooding e.g. Himalayas
- Changes to ice and snow fed lakes
ENSO- what happens in a normal year?
Trade winds blow westwards towards Australia. Warm winds due to the Equator create a surface ocean current. Deep cold water upwelling on the west coast of South America occurs. This brings nutrients so fishing is good. Rainfall occurs on the west coast of Australia.
