The Atmosphere - Physical Flashcards
What is nuclear fusion?
Sun releases energy in the form of electromagnetic radiation. The reactions involve joining the hydrogen atoms to produce helium + a neutron.
What is insolation?
Solar radiation reaching the Earth’s surface.
What is a dynamic equilibrium?
There is a balance between the amount of radiation that reaches the earth and that which leaves it.
Description and Importance of UV radiation.
Mostly absorbed by ozone. Prevents relatively high frequency radiation reaching the surface which could lead to skin cancer. UVA stimulates production of vitamin D in humans.
Description and importance of visible radiation/light.
Converted to chemical energy. In photosynthesis, molecule of water split with light energy.
Essential for reactions that take place in photosynthesis to occur.
Description and importance of infrared and visible.
Converted to heat energy. Levels of solar exposure between surface water and deeper parts leads to different water layers having different temperatures.
What are the likely causes and effects of global climate change on sea levels and ocean acidity?
- Kinetic energy in water increases, therefore occupies higher volume = thermal expansion.
- Glaciers melt into water adding additional water to sea.
- Sea levels rise 3mm per year.
- Oceans are alkaline. CO2 dissolved in water is acidic. This means ocean pH levels could become less alkaline, affecting many ocean organisms.
What are the likely causes and effects of global climate change on weather patterns?
-Higher temperatures lead to increased evaporation and precipitation.
- Areas that previously received rain may get less if too warm for water vapour to condense. Prevents farming.
- Changes in frequency and velocity of winds = increased storms/damage.
What are the likely causes and effects of global climate change on the cryosphere?
- Glacier movement: Meltwater causes glaciers to move quicker.
- Ice lakes: Water collected can create a lake which could lead to flooding.
- Reduced ice and snow cover: Increased temperatures reduce snow and the surface albedo.
- Loss of ice shelves: Form icebergs when they break.
What are the likely causes and effects of global climate change on the ocean circulation?
North Atlantic Current / Gulf Stream.
1) Water heats up in Gulf of Mexico.
2) Moves to North West.
3) Delivers warm water to Europe.
4) Water cools, more dense so drops.
5) This pulls more water from the Gulf.
Climate change could melt Greenland ice, reducing salinity (so density decreases) of water - falling of water at North wouldn’t happen. (A theory)/
What is El Nino?
Normally westward wind causes cold, nutrient rich waters to be drawn up near the coast of South America.
This can influence rainfall patterns.
In some years the winds creating the surface currents change direction. This can lead to a drop in rainfall in Eastern Australia, a loss of nutrient rich waters in South America as well as heavy rains and floods.
How is the Adelie Penguin being threatened by climate change?
Antarctic sea ice retreating due to increased global temperatures. Their food source (krill) is falling. They have to spend more energy hunting, less energy breeding and raising young.
How is the Golden Toad being threatened by climate change?
Drought and fungus and other climatic conditions killed them. They are extinct.
How is the sea turtle being threatened by climate change?
The beaches they lay eggs on are disappearing due to rising sea levels. Also, nest temperatures determine gender so increase in temperatures means only one gender will be prevalent in the nests.
What are the main ecological changes that may affect a species?
- Habitat loss.
- Food (e.g. competition).
- Temperature.
- Timing of natural events (e.g. early seasons).
- Light.
What are the impacts of climate change on health?
Disease vectors may be able to spread further e.g. mosquitoes.
What are the impacts of climate change on food supplies?
Reduced water availability may increase need for irrigation.
Mild winters may allow pests to survive easier and cause problems in following years.
What are the impacts of climate change on infrastructure?
Road heat stress due to increased temperatures.
Bridge damage.
Why are there often uncertainties in the data collected to show hw the climate has changed?
- Lack of historical data.
- Limited reliability of proxy data.
- Lack of understanding of natural processes that control weather, ocean currents etc.
- Time delay between cause and effect.
What is climate modelling?
Allows the effects of different, connected systems to be estimated.
Data is input from a particular year in the past to see if the model can predict the outcome for a later year.
Why are satellites useful for data collection?
- e.g. cryosat, can be used to collect info on ice cover.
- Low Earth Orbit satellites collect information from whole Earth Surface. Satellites in geostationary orbit collect less detailed info from a constant position. Includes microwaves and IR emissions.
- Can collect data on ice mass with sensors e.g. laster altimeters.
Monitoring ocean currents - Argo Floats.
Measure salinity, temperature, depth in an ocean profile.
Pops to the surface to transmit data - then descend again.
1) Float deployment.
2) Descent to drifting depth.
3) Drift for 10 days.
4) Descent to profiling depth (2000-6000m)
5) Ascent: Measuring all variables.
6) Data transmission.
7) Start next cycle.
What is positive feedback?
Change of an environmental factor causes environmental changes that increase rate of original effect.
What is negative feedback?
Environmental change causes a reduction of the original to re-establish equilibrium
What are 2 examples of negative feedback? Brief explanation.
- Increased low-level cloud = Higher temperatures increase evaporation which increases condensation which creates more clouds.
Less evaporation = less clouds = temps increase = more evaporation and so on. - Increased photosynthesis = Higher temperatures increase rate of photosynthesis.
Less photosynthesis = more CO2 = temperature increase = more photosynthesis ….
What are examples of positive feedback? Brief explanation for 2 of them.
- Increased forest and peat fires = High temperatures cause areas to warm up and dry out, causing more forest fires giving out CO2
Increased CO2 = increased greenhouse effect = increased temps = increased peat/forest fires = more CO2 … - More rapid decomposition of dead organic matter = Will release more methane.
Higher temps = more decomposition = more methane = increased greenhouse effect = higher temps …. - Melting permafrost and melting methane hydrate.
- Ocean acidification.
What is a tipping point?
The concept that human actions that cause climate change may cause changes in natural processes that themselves cause climate change to the extent that the original human actions are no longer needed for climate change to continue increasing.
What is geoengineering?
Deliberate large-scale altering of an environmental process that affects the earth’s climate (to counteract climate change).
What is the Kyoto Protocol (1992)?
An international agreement to reduce emissions of CO2, CH4, N2O etc.
Each country puts a ‘cap’ on emissions from large industries.
Any country unable to stay within their limit can buy emission credits from another country/company within its limit.
What are 2 well known international agreements?
- Copenhagen (2009)
- Paris (2015)
How do people adapt to climate change?
- Flood and coastal erosion control (e.g. sea walls, managed retreat).
- Improved building design (e.g. raised buildings, paler surfaces, resistant to storms).
What are some examples of geoengineering?
- Ocean fertilisation.
- Afforestation.
- Increased reflectivity from deserts.
- Direct capture and storage of CO2.
- Biomass energy with capture and storage.
- Biochar.
UVA
Wavelength.
Characteristic.
Environmental importance.
- 320 - 400nm
- Not absorbed by ozone.
- Human skin produces vitamin D as protection.
UVB
Wavelength
Characteristic
Environmental importance
- 280 - 320nm
- Almost fully absorbed by ozone.
- Prolonged exposure = sunburn, skin cancer, DNA mutations, crop damage etc.
UVC
Wavelength
Characteristic
Environmental importance
- 100 - 280nm
- Completely absorbed by ozone and normal oxygen.
- Kills bacteria and viruses. Plants reflect UV radiation off their flowers to attract insects for pollination.
Complete the balanced equation for the breakdown of ozone by chlorine to form chlorine monoxide and ozone.
Cl + O3 –> ClO + O2
Complete the balanced equation for the formation of chlorine dioxide from chlorine monoxide and an oxygen atom.
ClO + O –> ClO2
Complete the balanced equation for the formation of chlorine and an oxygen molecule from chlorine dioxide.
ClO2 –> Cl + O2
What is the overall equation of the breakdown of ozone by chlorine?
Cl + O3 + O –> 2O2 + Cl
What is the natural chemical reaction involving the different forms of oxygen in the stratosphere?
O3 –UV–> O2 + O
(Monatomic oxygen reacts with diatomic oxygen to form triatomic oxygen (Ozone).
Why is ozone depletion greatest in Antarctica?
- In the area over Antarctica, there are stratospheric cloud ice particles not present anywhere else.
- These clouds are composed of ice crystals that provide surfaces for reactions that increase breakdown of ozone.
- Winds around Antarctica create a ‘polar vortex’, resulting in high chlorine concentrations and low temperatures.
- When spring arrives, light splits chlorine molecules to produce free chlorine radicals that cause ozone depletion.
What are CFCs?
Chlorofluorocarbons - chemically stable, non-toxic, non-reactive in troposphere, not flammable, liquefied under high pressure.
What are some uses of CFCs?
Refrigerant
Aerosol propellant
Asthma inhalers.
What are the problems with using CFCs?
When they react with UV light, a Cl molecule is released which causes ozone depletion. They are predicted to last 1000s of years in the troposphere.
Methods of reducing CFC usage:
International agreements.
Alternative materials.
Alternative processes.
Disposal techniques.
- Montreal Protocol - use of CFCs to phase out by 2030. Banned.
- HCFCs (as refrigerant) = less chemically stable than CFCs so break down before they even enter stratosphere.
CFCs in asthma inhalers replaced with hydrofluorocarbons (HFAs). - Pump action sprays, stick/roll-on deodorant.
- Waste CFCs from fridges and AC are drained and taken by council. They are incinerated (which breaks them up into CO2 and acidic gases which can be neutralised).
Why was the Montreal Protocol more effective at controlling FC emissions than the Kyoto Protocol has been at controlling greenhouse gas emissions?
- More evidence for ozone depletion / public awareness.
- Alternatives to CFCs more readily available / fossil fuels are difficult to replace.
- Montreal BANS CFCs, Kyoto sets TARGETS for GHG.
