The Atmosphere Flashcards
What are the % of gases in the air?
(Present)
N-78
O-21
Co2-0.04
Rare gasses-1
Ozone-0.000007
How is oxygen presented in the atmosphere?
O,O2,O3
Known as monatomic, diatomic and triatomic oxygen
Together they form ozone
How does incoming visible light lead to the warming of the earth
The incoming visible light is absorbed, converted to heat and re-emitted as IR. Gasses in earths atmosphere absorb this IR energy and convert it to heat.
-the warm atmosphere emits IR energy which is absorbed by earths surface
-the warm atmosphere reduces heat loss by conduction from land and the oceans
What is the North Atlantic conveyor?
A wind that blows over the oceans creates the current what distributed heat by carting warm water from tropical areas
Where do 80% of gasses in our atmosphere lie?
Troposphere
Describe troposphere
0-10km
Temp decreases with height
Contains almost all h20
Describe stratosphere
10-50km
Temp increases with height due to absorption of UV radiation by ozone
“The ozone layer”
Describe mesosphere
50-90km
Temp decreases with height
Describe thermosphere
Above 90km
Strok temp increase due to absorption of UV radiation by o2 and n2
What happened to incoming solar radiation
Either
1) reflected by clouds or earths surface
2)absorbed by earths atmosphere
- could be absorbed into earth or is emitted back into space
3) absorbed by earths surface,
Emission of IR - leads to long wave IR emitted to space
What is a CFC
chloroflucarbons - they were used in fire extinguishers and refrigerants
What is a NOx
Oxide of nitrogen - fertilisers can increase NOx emissions
Ecological changes to climate change
Species may be affected directly to temp
Temp rise causes plants to grow faster- toxic ones will produce more toxins
Oak trees have deeper roots so would survive droughts better than beech
Hibernation patterns disrupted causes them to use up stored fat and might stave before spring
Changes in climate processes due to climate change
Wind pattern changes:
Jet streams are getting smaller and moving slower- this can cause weather systems to remain over an area, creating longer, more intense weather
Changes in rainfall:
Increased temp means more evaporation so more rain
Changes in cryosphere due to global warming
Less snow/ ice so reduces albedo and less sunlight is reflected away and more is absorbed causing further heating
Loss of ice shelves- as it flows into the sea- increasing sea temp
Ice lakes- water produces by melting ice can collect on the surface on glaciers producing ice lakes. If the front wall of the lake melts then a sudden rush of water may be produced causing flooding - this is serious in the Himalayas
How can rising temp cause sea level rise
Thermal expansion of water:
Seawater heats therefore expands causing sea level rise, however this will take a very long time as there is a huge quantity of water in oceans and water has a high specific heat capacity.
Melting land ice:
Ice melts and increases volume of sea increasing sea level
Changes in ocean currents due to climate change
-Winds cause surface water to move
-Evaporation causes water to flow in to replace water that has evaporated
-heating causes the density of surface water which affect ease with witch surface water sinks
-salinity changes due to evaporation, or inflow of melted ice affectes water density
What is the North Atlantic conveyor (gulf stream)and what drives it
The North Atlantic conveyor (Gulf Stream) involves the movement of layers of surface and deep water in the North Atlantic Ocean which distributes heat energy and controls the climate
1) friction in the prevailing winds blowing over ocean surface blows in same direction (south west USA to north west Europe)
2) water in North east Atlantic sinks as it fills and becomes denser, drawing water in to replace it
Changes in the Gulf Stream caused by global climate change
Higher atmospheric temps cause land ice on Greenland to melt and flow into the sea. This dilutes sea water causing the salt conc to decrease . This means less dense water so less lightly to sink. This reduces flow rate and can cause NW Europe to become colder
What is El Niño
An El Niño year happens every 2-7 years
In a normal year the winds blow west wards from South America to Australia. This causes cold water to be drawn up in the coast of South America. This water is rich in nutrients and causes large agal blooms feeding a large web including commercial fisheries.
The currents heats as it moves.
Is also affects rainfall- if current is cold at the coast then water bearing winds will cool down and cause water vapour to cool, condense and fall as rain. Its current is warm opposite happens.
In an El Niño year the winds that create the surface currents change direction, this means no nutrient upwelling of South America. Rainfall in eastern Australia is decreased and in South America there are droughts
Impacts of El Niño years
Droughts in NE Africa , S Africa and china
Fewer hurricanes in North Atlantic
Fewer cyclones in Japan
Explain La Niña
The event occurs when more strong winds blow in the normal direction, water currents are spend up and temp differences between Australian and South American are increased
Impacts of climate change on human society
Water supplies can decrease due to droughts and evaporation
Food supplies - crop spices will change due to temp and water availability
Impacts on infrastructure:
1) road heat stress- tar melts causing road to deform
2) track buckling- high temp can cause rail track to expand and buckle.
3)drainage- higher rainfall will increase flooding risks
4) bridge damage- high river flow can put pressure on bridges
5)landslides- heavy rain can water log the ground and lubricate the soil and rock particles, making landslides more likely
What is a time scale and a spatial scale
Time:
Short term-sudden storm
Long term-a trend of windfall increasing windfall
Spatial scales:
Local-sudden slow moving storm causing local flooding
Regional- area with increased rainfall due to increased evaporation
Global-increased global temp due to increased IR absorbtion
Proxy data
Dendrochronology-width of tree ring shows grow rate and co2 levels
Coral species- produce large coral heads with rings to estimate sea temps
Ice core data
Air bubbles trapped in ice tell us info about atmospheric levels
Ice have layers which can be determined to find the age via radio-isotope analysis
Negative feedback loops
Increased low -level cloud
Higher temp increase evaporation, increased condensation and more clouds. Clouds albedo the sun lights so the warming of earth is reduced
Photosynthesis- high temp, more photosynthesis, less Co2 , less co2 rise so warming will b reduced
Carbon storage
Carbon sequestration- planting more trees would sequester carbon in wood through photosynthesis
Carbon capture storage (CCS)- removes Co2 emissions from factories, Co2 is captured , transported and stored in depleted oil fields
How is ozone formed
UV light splits a diatomic oxygen molecule
Two monatomic oxygens are released
Each monatomic oxygen reacts with a diatomic oxygen to form triatomic oxygen/O3/ ozone
How is ozone destroyed
UV splits a ozone molecule to a monatomic and a diatomic oxygen
Why are CFCs bad?
Stable so stay in atmosphere for a long time
In stratosphere they are exposed to a higher level of UV which they absorb and break into carbon and chlorine bonds and releases chlorine free radicals.
Chlorine reacts with a monatomic oxygen therefore preventing it reacting with O2 to form ozone
What was the outcome of the Montreal protocol
CFC are banned
HCFCs will be phased out by 2030
Some essential ODS are still permitted
Use of alternative processes:
Pump action sprays are now used
Stick or roll on deodorant
Use of alternative materials:
HFCs to replace HCFCs and they contain no chlorine
Safe disposal of waste CFCs
Waste CFCs are drained and incinerated, then neutralised with crushed lime
