The Atmosphere

• What are the 4 layers of the atmosphere (Earth to sky)?

  Troposphere, Stratosphere, Mesophere, Thermosphere
• What are the inner and outer cores mate from?

  Inner core: Solid iron and Nickle.

  Outer core: Liquid iron and Nickle.
• How does the atmosphere support life? Give 6 ways.

  > Gases for natural processes: The atmosphere contains N2, O2, CO2 and H2O which are needed to make the biological molecules used by living organisms.

  > Absorption of electromagnetic radiation from the sun

  > Delaying the escape of infrared energy

  > Heat distribution

  > Ocean currents: Winds blowing over the oceans create currents that distribute heat by carrying warm water from tropical areas to higher latitudes, such as the North Atlantic Conveyor.

  > Transport of water vapour : Winds transport water vapour to areas that would otherwise get little or no perception.
• What are the 4 layers of the Earth from the centre to the edge?

  Inner core, Outer core, Mantle, Crust
• How does ozone form and how does it get broken down. Give equations.

  UV radiation splits some oxygen molecules into oxygen atoms (O2->O+O). An oxygen atom can then combine with an O2 molecule to form ozone (O2+O->O3). Ozone can be broken down by UV radiation (O3->O2+O).
• What percentage of the atmosphere is nitrogen? What increases and decreases it and where is it used?

  78%, increased by denitrification (conversion of soil nitrates to nitrogen), decreased by nitrogen fixation (conversion of nitrogen to ammonia). Used to keep food fresh.
• What percentage of the atmosphere is oxygen? What increases and decreases it and where is it used?

  21%, increased by photosynthesis, decreased by aerobic respiration. Used in breathing gases in healthcare.
• What percentage of the atmosphere is Carbon Dioxide? What increases and decreases it and where is it used?

  0.04%, increased by aerobic respiration, decreased by photosynthesis. Used in fire extinguishers.
• What percentage of the atmosphere is Water Vapour? What increases and decreases it and where is it used?

  0-4%, increased by evaporation, decreased by condensation. Used in steam turbines.
• What percentage of the atmosphere is methane? What increases it?

  0.00017%, increased by anaerobic respiration by bacteria.
• What's a dynamic equilibrium?

  A combination of active processes that cancel each other's effects so that there is no overall change.
• Why is the atmosphere important?

  - O2 supporting aerobic respirations.

  - CO2 for photosynthesis

  - Ozone soaks up UV

  - Maintains constant(-ish) temperature.
• Troposphere. How far from the Earth is it? How does temperature change with height?

  0-10KM, Temperature decreases with height.
• Stratosphere (ozone layer). How far from the Earth is it? How does temperature change with height?

  10-50KM, Temperature increases with height.
• Mesosphere. How far from the Earth is it? How does temperature change with height?

  50-90KM, Temperature decreases with height.
• Thermosphere. How far from the Earth is it? How does temperature change with height?

  90+KM, Strong temperature increase with height.
• What is meant by the term 'Albedo' mean?

  The ratio between the total solar radiations reaching a surface and the amount of reflections.
• What's the cryosphere?

  Land that is mainly covered with snow and/or ice.
• How can less snow cause global warming?

  Reduces the albedo of the Earth's surface therefore less sunlight is reflected and more is absorbed.
• What is nuclear fusion?

  When two nuclei are forced together and form a large nucleus. Two hydrogen nuclei form a hydrogen nucleus.
• What is UV-A?

  UV rays that cause sunburn but used by the skin to synthesis. Contains vitamin A. We evolved to live with it and use it.
• What is UV-B

  Higher energy UV rays than UV-A. Damages organic molecules such as DNA and chlorophyll.
• What is UV-C?

  Higher energy UV rays than UV-B. Would be rapidly fatal but is filtered out before it reaches the ground.
• What are the consequences of Global Warming?

  > Sea level rise - Heating of the sea causes water to expand

  > Changes in rainfall

  > Ocean current change

  > Ecological Changes - Changes in abiotic and biotic factors can affect a species' chance of survival.

  > Impacts on Human Society
• What evidence do we have for the enhanced greenhouse effect?

  > Historic data

  > Proxy data

  > Ice core data

  > Satellite data

  > Monitoring ocean currents

  > Computer models
• What are Global Warming's impacts of human society?

  > Health - Problems from heat waves such as heart disease and respiratory problems.

  > Water supplies - Droughts and floods

  > Food supplies - Change crop species, reduce water available for irrigation, pest damage.

  > Impacts on infrastructure. Changes in temperature and rainfall have impacts on how society operates (such as road heat stress, track buckling, drainage, landslides and bridge damage).
• Name 6 ways we adapt to climate change.

  > Building design to cope with raised temperature or increase in storms.

  > Different crop species to cope with drier conditions.

  > Coastal erosion control.

  > Managed retreat.

  > Urban drainage control.
• What are the 4 processes that cause changes in the ocean currents?

  1) Winds - Change in surface movement

  2) Evaporation - Cause water flow

  3) Changes in density - changing mean water that sinks or rises.

  4) Salinity - Changes due to evaporation or freshwater input from land.
• What is the North Atlantic Conveyer (the 'Gulf Stream')

  The North Atlantic Conveyer involves the movement of layers of surface and deep water in the North Atlantic Ocean which distribute heat energy and control the climate. Warm water from the tropical Atlantic Ocean travels north-eastwards towards North-West Europe. Two processes drive this movement:

  > Friction with the prevailing winds blowing over the ocean surface from the southwest to north-west causes surface water to flow in the same direction.

  > Water in the North-East Atlantic sinks as it cools and becomes denser, drawing water in to replace it.

  
  

  The UK is warmed by the North Atlantic Conveyer which brings water from tropical regions. This prevents the cold weather found in the regions of the same latitude, for example, Moscow, or Churchill, Canada where Polar bears are found.
• Outline the effect of melting ice on the North Atlantic Conveyor.

  > Prevailing winds from the south-west blow water towards north-east

  > Water cools as it flows further from the equator.

  > Freshwater is less dense than seawater. It dilutes the cold seawater. Being less dense than normal, it sinks less easily, slowing the current down.

  > This causes the current to slow down
• What is the Roland-Molina hypothesis?

  The theory that CFCs will cause significant ozone depletion as they release a Cl atom when exposed to solar radiation.
• What were CFCs used for and why?

  They were used for refrigeration and propellants because they are non-flammable and non-toxic.
• How do CFCs cause ozone depletion (use equations)?

  UV rays cause a chlorine atom to be detached from a CFC. This chlorine radical reacts with ozone to create an oxygen chlorine radical and an oxygen molecule (Cl• + O3 -> ClO• + O2). The oxygen chlorine radical reacts with an oxygen atom to form an oxygen molecule and a chlorine radical which repeats to deplete ozone (ClO• + O2 -> O2 + Cl•)
• Give 3 pieces of evidence for ozone depletion.

  > Ground-based data - Detection of UV rays by scientists on the ground in Antarctica led to the conclusion that ozone was decreasing.

  > Satellite survey - The amount of UV rays reflecting off the Earth's surface is measured and it was concluded that ozone was decreasing.

  > Air Samples - Helium balloons and research aircraft were sent up high into the ozone to take samples of the gas which confirmed ClO and Cl is high concentrations.
• Explain how we are managing the release of CFCs

  The Montreal Protocol reduces the use and release of CFCs and the use of HCFCs will be phased out by 2030s
• What are replacements for CFCs? Give a pro and a con.

  Hydrochloroflurocarbons (HCFCs). They have similar properties to CFCs but are powerful greenhouse gases.
• What is the Kyoto Protocol?

  An international agreement to reduce emissions of carbon dioxide and other greenhouse gases. MEDCs sign up to treaty to reduce emissions of six greenhouse gases by 5.2% of 1990 emissions.