Atmosphere Flashcards
What is the Atmosphere?
What is the atmosphere?
The gases which surround the Earth
What is the composition of the atmosphere?
78% nitrogen
21% oxygen
0.04% carbon dioxide
What are the layers in the atmosphere?
Troposphere
Stratosphere
Mesosphere
Thermosphere
What is absorbed by the ground?
Incoming short wave radiation from the Sun
What does this result in for the Troposphere?
The air next to the ground heating up by conduction
Why is the temperature profile said to be unstable?
The air rises and then cools
How is the stratosphere heated?
Said to be heated from ‘within’. Due to chemical reactions in the ozone layer
How the atmosphere supports life
What gases does the atmosphere contain and what are these used for?
Carbon, oxygen and hydrogen
Makes biological molecules used by living organisms
What does the upper atmosphere block?
Harmful radiation from solar winds
What block ultraviolet light?
Oxygen in the stratosphere
What is the ozone made of?
o, o3 and o2
What is an example of heat distribution?
Tropical regions absorb most heat energy from the Sun.
The warm surface heats the atmosphere. Which distributes the heat cooler region
What do ocean currents distribute?
Heat and nutrients
How is water vapour transported?
Wind
The greenhouse effect
What is the first stage of the greenhouse effect?
Short wavelength, solar radiation passes through atmosphere
What is the second stage of the greenhouse effect?
The ground absorbs the radiation and heats up
What is the third stage of the greenhouse effect?
The ground re-emits heat as long wave infrared radiation
What is the fourth stage of the greenhouse effect?
Infrared radiation is absorbed by greenhouse gases in the atmosphere
What is the fifth anthropogenic stage of greenhouse effect?
Increase levels of greenhouse gases in the atmosphere from human activity means more infrared radiation is absorbed leading to global warming
El Nino
What is EL Nino?
A sequence of events which naturally occur every 5 to 7 years
Normal Pacific conditions
East trade winds blow a surface current East to West across the Pacific as it does it warms and accumulates
Conditions in the east during normal seasons
Cold surface water produces sinking air therefore the climate is dry
Conditions in the west during normal seasons
Warm surface water heat the air which rises and condenses to form clouds therefore the climate is wet
El Niño Pacific conditions
Tradewinds weaken stopping the current meaning warm surface waters move from West to East
Conditions in the East during El Nino
Warm surface water produces rising air which increases rainfall leads to flooding and higher sea levels
Conditions in the West during El Niño
Cold surface water producers sinking air therefore rainfall decreases causing drought and wildfires
Impact of El Nino
How many people can be affected by El Nino?
60 million people by drought and flooding
How can the U.K.’s weather be affected?
Colder winters and wet conditions due to weakening of the Atlantic jet stream
What happens to upwelling?
It is weakened or stopped which brings cold nutrient rich water to the surface this result in reduced plankton which reduces food for fish
What is the temperature change?
The whole planet can warm by 0.2°
Changes in Climate processes due to Global warming
What is the jet stream?
a fast moving ribbon of air, which moves west to east at the top of the troposphere.
What is the jet streams maximum speed? What is it driven by? And what does it drive?
Maximum speed is 250 mph, is driven by temperate differences and it drives weather in the troposphere
What happens if global warming alters the position or strength of the jet stream?
It will move north and weaken as a result middle latitudes such as the UK will have milder drier weather
What could be the effects of a temperature rise?
May result in an increase of herbivores as plants grow faster
What could be result of precipitation change?
Could cause wetlands to enlarge or shrink
What effect could global warming have on biotic factors?
The timing of ecological events such as flowering, migration and nesting may change therefore interdependence may be reduced
What could be the effect on species distribution?
species could colonised areas that may not be suitable
What can cause species fragmentation and what is it affect?
Population may become isolated by sea level rise. This can result in reduced gene pool and problems with repopulation
What are the difficulties of predicting global climate change?
Lack of historical data
limited reliability of proxy data
lack of understanding of natural processes
limitations of computer modelling
limited coordination between researchers
What is a feedback mechanism?
A change in one environmental factor may cause other features to change this may have an effect on it’s original change such as global temperature and carbon dioxide concentration
What is a negative feedback mechanism?
Situation where an initial change causes a reaction that decreases the original change
What is an example of negative feedback?
Higher temperatures increase of evaporation this increases condensation therefore clouds as a result warming is reduced to clouds having higher albedo
What is positive feedback?
Situation where initial change causes a reaction that increases the original change which is either temperature directly or concentration of greenhouse gases
Why are scientists worried about these?
They are linked to climate tipping points
What is an example of positive feedback?
Warming causes frozen soil to defrost therefore trapped methane is released. warming increases due to increase levels of atmospheric methane
Control of Global Climate change
How can you control levels of atmospheric carbon dioxide?
Reduce fossil fuel use
Use energy resources with low carbon emissions
Carbon sequestration
How can you reduce levels of atmospheric methane?
Reduce landfill waste
Reduce livestock production
Improve recovery of gas from coal mines, gas and oil facilities
How can you reduce atmospheric levels of oxides of nitrogen?
Reduce use of internal combustion
Use catalytic converters in vehicle exhaust so harmful gases are removed and converted into nitrogen and oxygen
Add urea to power station effluents or diesel engine exhaust
How to reduce atmospheric levels of chlorofluorocarbons
Use alternative materials in manufacturing
What is tropospheric ozone?
Is a secondary pollutant not emitted by humans but as a result of primary pollutants interacting to produce ozone in the presence of UV light
What can be the effect of tropospheric ozone?
Can worsen respiratory complications such as asthma
How can carbon sequestration be increased?
Plan more trees. This fixes carbon from the atmosphere into biomass, through photosynthesis. However is only temporary as trees will die, decomposed and release carbon back
What is another way carbon sequestration can be increased?
Developing artificial trees, some of which use plastic to absorb carbon dioxide from the atmosphere. However, this can be expensive.
What is the method of carbon storage?
Store carbon released from power stations and other large stationary emitters of carbon underground below the cap rock where previous oil and gas has been extracted
What are the positives and negatives of this?
Has large capacity and some of the infrastructure is already in place.
However it does not work for diffuse sources
What is an example of Geo engineering?
Seeding the atmosphere with sulphur dioxide particles to reflect sunlight
What are the implications of this?
It cannot be reversed can reduce the global initiative to reduce emissions and cause termination shock.
Adapting to Climate change
How can flooding be controlled?
Flooding caused by rising water levels can be reduced by building higher riverbanks or coastal defences.
If water levels rise above the level of the land it would be necessary to pump rainwater from the land up into a river or sea.
What is an example of flood control?
The Thames barrier
How can coastal erosion be controlled?
Variety of seawall and wave screens to protect the coast from waves.
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