Chapter 4 - The Atmosphere Flashcards
what is the atmosphere ?
The thin layer of gases surrounding the Earth, held in place by gravity
What gases are in the atmosphere ?
Nitrogen, Oxygen, Carbon dioxide, Rare gases and Ozone
What percentage of the atmosphere are the diff gases ?
Nitrogen = 78%
Oxygen = 21%
Carbon dioxide = 0.04%
Rare gases (combined) = 1%
Ozone = 0.000007%
True or false, the atmosphere is often in dynamic equilibrium ?
True
whats a reason that we need C, O2, H2 and N2?
Needed to make biological molecules used by the living molecules
what is the ozone made out of?
O, O2, O3
two ways earths temperature is increased ?
- the warm atmosphere emits infrared energy which is absorbed by the earths surface
- the warm atmosphere reduces heat loss by conduction from land and the oceans
Describe how heat distribution occurs is tropical areas
Warm surface heats the atmosphere above this heat is distriuted to higher latitudes by warm winds
what does wind blowing over oceans do to the current ?
wind blowing over oceans creates currents that distribute heat by carrying warm water from tropical areas to higher altitudes
what do winds do to the transport of water vapour ?
winds transport water vapour to areas that would otherwise get little to no precipitation
what does atmospheric pressure do to evapouration of water molecules ?
controls the ease with which water molecules can evapourate and escape from the water surface.
what order is the structure of the atmosphere ?
- troposphere
- stratosphere
- mesophere
- thermosphere
what is the natural greenhouse effect ?
a natural process that warms the Earth’s surface
what would happen if we didnt have the natural greenhouse effect ?
the atmosphere would be 33 degrees colder than it is
what are human activities which increase atmosohereic concentration for carbon dioxide ?
- combustion of fossil fuels and wood
- ploughing of soils
- drainage of marshes and bogs
what are 3 human activities which increase atmosohereic concentration for methane ?
- Anaerobic respiration by microbes in padi fields, landfill sites, and intestines of livestock
- produced during formation pf fossil fuels
- released by ventilation of coalmines, leaks from natural gas fields and pipelines
what are human activities which increase atmosohereic concentration for oxides of nitrogen ?
- oxygen and nitrogen from the air react at high temos in locations sich as vehicle engines and power stations
- fertiliser use can increase NOx emissions
what are human activities which increase atmosohereic concentration for CFC’s ?
- aerosol propellants
- fire extinguishers
- refrigerants
- solvents
- expanded foam plastics
what are human activities which increase atmosohereic concentration for tropospheric ozone ?
photochemical breakdown of NO2 and subsequent reactions with oxygen
abiotic factors as a consequequence of global climate change - rain
- may grow plants faster
- species may be directly affected
abiotic factors as a consequence of global climate change - precipitation
- changes may cause wetland habitats to enlarge or shrink
what species are most likely to be affected by ecological change ?
species that are close to the edge of their range of tollerance
how can climate change affect bats ?
- warmer shorter winters may increase survival during hibernation
- warmer weather may increase population of food species
- wetter stormier weather may reduce the time for witch bats can feed
when is colinisation only possible ?
If suitable new areas exist and if biological corridors exist to link the areas
when there is little to no population movement why may this cause problems in the future for species survival ?
- gene pool may be divided into smaller groups which makes inbreeding more likely
- it may not be possible for a new population to repopulate if previous species has died out
what are jet streams ?
changes in climatic processes
strong winds that blow from west to east along meandering path in upper troposphere
how is a jet stream caused ?
changes in climatic processes
Difference in temperature and density between two air masses
what is the coriolis force ?
changes in climatic processes
the action of the earth spinning which means that the air does not blow straight
what do jet streams control ?
changes in climatic processes
movement of airbodies that create rain
polar regions are warming faster, what does this mean for the jet streams ?
This means that the temperature differences that create the jet streams are getting smaller
Jet streams are moving slower, what does this mean for weather system changes ?
changes in climatic processes
slower movements means that weather systems remain over an area longer, creating more intense and longer weather (E.G. prolonged droughts)
evapouration has increase what does that mean for temperature ?
changes in climatic processes
Increased
More evapouration means what for precipitation elsewhere ?
changes in climatic processes
increased
what can changes in wind direction do to precipitation ?
changes in climatic processes
It may affect precipitation by carrying the humid air to new areas causing increase rain in some areas but reduced in others
What does less snow / ice cover do to the albedo ?
Changes in cryosphere
Reduces it
what does reducing the albedo do ?
Changes in cryosphere
less sunlight is erflected away and more is absorbed, causing further heating
How is a glacier formed ?
Changes in cryosphere
Snow that falls on land collects, compacts into the ice which gradually flows downhill as the mass builds up sufficiently to create a glacier
what may warmer temperatures do to the front of the glacier ?
Changes in cryosphere
front end of the glacier melts faster than it is moving forward so it retreats up the valley
what may cause the glacier to move faster ?
Changes in cryosphere
meltwater from the surface may flow down the cracks of the ice to the bottom of the glacier where it slides over the rock more easily
what happens to the level of the sea when ice shelves are broken up ?
Changes in cryosphere
does not change becuase the ice has already displaced the water
what happens in warmer conditions to river flow ?
Changes in cryosphere
increase, in rivers relying on meltwater
does water in the sea have high or low specific heat capacity ?
sea level rise
High
what happens to sea water when it heats ?
Sea level rise
it expands and therefore causes sea levels to rise
what happens if land ice heats up ?
Sea level rise
Land ice will melt if temperatures increase, this will then flow into the sea to increase sea levels
what are processes that effect the ocean currents ?
Changes in ocean currents
- wind causes surface water to move
- water has to flow in to the space left the replace water thats been evapourated
- density of water surface will be effected by heating and cooling
what is the north atlantic conveyor (‘gulf stream’) ?
Changes in ocean currents
movement of layers of surface and deep water in north atlantic ocean
how can NW europe become colder due to warmer temperatures in terms of the north atlantic conveyer ?
changes in ocean currents
- Higher atmos temps cause land ice on Greenland to melt & flow into the sea
- This dilutes sea water
- Less saline water is less likely to sink so flow rate of water currents will be reduced
- NW Europe could become colder because of this
What is El Nino ?
changes in ocean currents
a climate pattern that describes the warming of surface waters, occurring naturally every 2-7 years
what are the normal conditions not in El Niño ?
changes in ocean currents
- Reliable trade winds blow westwards over the Pacific ocean
- then nutrient rich water is brought up from deeper near the coast of south america
- causes a large algal bloom which support a rich food web
- current continues to get warmer as it eventually reaches austrailia
What happens in El Nino years ?
changes in ocean currents
- winds that create the surface currents change direction
- Ocean current will slow or reverse
- No upbringing of nutrient rick water –> means the ricch food web collapses
- rainfall patterns change
What are 2 examples of global impacts of El Nino ?
changes in ocean currents
- droughts in africa and china
- 1912: Southward movement of icebergs from Greenland that caused the sinking of the titanic
what is the cause of El Nino if there is one that has been discovered ?
changes in ocean currents
No cause found as of yet, but they seem to be getting more frequent
When does La Nina occur ?
changes in ocean currents
when the wind blows more strongly in the normal direction
What happens in La Nina ?
changes in ocean currents
- water currents will speed up and temperature differences between western and eastern are increased
- Future global weather patterns will become more unpredictable
What is the Heat island effect ?
Consequences of climate change on human society
Heat emissions & light absorption by dark surfaces make heat waves worse in urban areas
What are some consequences to health as a concequence of climate change ?
Consequences of climate change on human society
- Temperatures in some areas may reach the end of the human range of tollerance –> means that health problems caused by heat waves become more likely
- Heat island effect
- Disease vectors may change distribution as temps
What is a consequence to Water Supplies as a concequence of climate change ?
Consequences of climate change on human society
Changes to evaporation, precipitation & water flow may create water supply issues from droughts to floods
What are some consequences to food supplies as a concequence of climate change ?
Consequences of climate change on human society
- An increase in temps may affect water availability which impacts the ability for crops to grow –> impacts on food security
- heavier dependance on irrigation (link to overexploitation of aquifers)
- hotter weather –> more pests able to survive in more places –> cause more damage
What are some consequences to infrastructure as a concequence of climate change ?
Consequences of climate change on human society
- drainage : higher rainfall –> higher flood risk
- Landslides : higher rainfall can waterlog the ground and make it more suseptable to ladnslides
- Road heat stress : Higher temps can melt and disfigure tar on the roads which will need to be relaid with tar with a hgih melting point –> more money needed to be spent
What is are some examples of short and long term time scales ?
Difficulties in monitoring & predicting climate change
- short term : sudden storm/ wetter winter
- long term : trends of winters with more rainfall
what are two things that effect Spatial scales ?
Difficulties in monitoring & predicting climate change
- changes can occur on local, regional and global changes
- Particular changes may occur in different locations at different times
What are the problems that we have with predicting interconnected systems ?
Difficulties in monitoring & predicting climate change
- We don’t fully understand processes controlling the atmosphere, hydrosphere, biosphere and the interactions between them
- Interactions between the systems at different scales and the combined effect this will have is difficult to predict
What are some problems with predicting when there are natural fluctuations ?
Difficulties in monitoring & predicting climate change
- global climate has never been contant
- solar orbit naturally causes environemntal changes
- may hide or exaggerate anthropogenic change
What is anthropogenic change ?
changes which are the result of human activities
What is proxy data ?
Data Collection
making an estimate about one factor that can’t be measured by using a related factor which can be measured or estimated
What is one example of proxy data ?
Data Collection
Dendrochronology : width of a tree ring can reveal info about the growth rate of the tree, age and temperature at time tree was laid down
What are some problems with histroic data ?
Data Collection
- Methods used in the past may not be as advanced therefore inaccurate
- May be a lack of data collected on a global scale
- Local scale data may be unrepresentative
How can we use ice core data to reveal info about the historical atmosphere ?
Data Collection
Air bubbles trapped in snow/ ice provide info about atmosphere at the time they were trapped
(eg. CO2 concentration)
What type of data can be collected by satellites ?
Data Collection
- ocean currents
- ice cover and thickness
- vegetation cover
- temperature
What are the two types of satelites and what do they do?
Data Collection
- Low earth orbit satellites : obributs the whole earth and collects detailed info
- Geostationary satellites : these are less close to the earth –> less detailed, used to moniter weather / climate
how can surface currents be monitered ?
Data Collection
With satelites
How can deeper ocean currents be measured ?
Data Collection
with argo floats which are programmed to go to a certain depth and remain for certain time
What is the equation for negative feedback ?
Feedback Mechanisms & Tipping points
Change in process A –> change in process A causes a change in process B –> change in process B counteracts the change in process A –> origional change is reduced
When does negative feedback occur ?
Feedback Mechanisms & Tipping points
when an environmental change causes another which then decreases the effect of the original one (this re-establishes the origional equilibrium)
What are 2 examples of negative feedback ?
Feedback Mechanisms & Tipping points
- clouds
- photosynthesis
Explain the photosynthesis negative feedback
Feedback Mechanisms & Tipping points
Higher temps → more photosynthesis → more co2 removed from atmosphere → less warming will occur
Explain the positive feedback equation
Feedback Mechanisms & Tipping points
Process A → Change in process A causes a change in process B → increases the original change in process A
When does positive feedback occur ?
Feedback Mechanisms & Tipping points
when an environmental change occurs which sets off another, this then increases the rate of the original change
What are 2 examples of positive feedback ?
Feedback Mechanisms & Tipping points
- melting permafrost
- ice and snow melting
Explain how the positive feedback works in ice and snow melting
Feedback Mechanisms & Tipping points
Warming melts the ice & snow → the albedo effect is reduced → causes further warming
what is a tipping point ?
Tipping points
human actions that cause climate change may cause changes in natural processes that themselfs cause climate change so the original human action is no longer required for climate change to continue
What is an example of tipping points ?
Tipping points
Snow on land melting caused by increasing temps reduces earth albedo so temp is raised further causing more snow to melt
what is one method to control carbon dioxide ?
Control of global climate change
carbon sequestration by planting more trees to absorb CO2
what is one method to control methane ?
Control of global climate change
Reduction in landfill use
what is one method to control oxides of N ?
Control of global climate change
increasing the use of catalytic converters
what is one method to control chloroflourocarbons (CFCs) ?
Control of global climate change
Alternative materials in manufacture and appliance operation (eg. reduce the use of aerosols)
what is one method to control tropospheric ozone ?
Control of global climate change
Reducing emissions of nitrates of oxygen reduce the formation of ozone in the troposphere
What is carbon sequestration ?
Control of global climate change
planting more trees to sequestrate carbon through photosynthesis
What is carbon capture and storage CCS ?
Control of global climate change
Technology to remove and store carbon released by fossil fuel factories
what is geoengeneering ?
Control of global climate change
Technologies that can influence natural processes to reduce the anthropogenic greenhouse effect
What are examples of geoengineering ?
Control of global climate change
- Painting roofs white to increase their albedo
- Putting solar shades in orbit to reduce sunlight reaching earth
2 techniques to reduce flooding from a sudden increase in rain
Adapting to climate change
- Permeable urban surfaces
- River flow management
2 methods to control erosion from the sea
- sea walls
- groynes
what is managed retreat ?
- Cost of flood protection may be greater than the value of the land in some cases so it is left to flood