Water and Carbon Cycle - Knowledge Flashcards
What is a system?
a set of inter-related events or components working together to produce an outcome
what parts does a system consist of?
inputs, stores, outputs, flows
what type of system is the water cycle? Why?
a closed system water is neither created or destroyed on a large scale
what is a closed system?
energy is transferred beyond the system but not matter
what type of system is the carbon cycle? Why?
closed system carbon is neither created or destroyed, it just cycles
what is dynamic equilibrium? give an example?
when inputs and outputs are balanced when both constructive and destructive waves act on a beach, but the sediment remains broadly the same.
what are the five spheres of earth systems?
atmosphere, cryosphere, biosphere, lithosphere, hydrosphere
Complete the following negative feedback example; -increase in CO2 -increase in temperature -increased plant growth
- increased uptake of co2 from plants -reduced co2 in atmosphere
complete the following positive feedback example: -increase in temperature -increase in ocean temperature -dissolved co2 released from warmer oceans
-increase in co2 - further atmospheric warming
Of the worlds water, what percentage is ocean water and what percentage is freshwater?
97% ocean water 3% freshwater
Describe the distribution of the earth’s freshwater in each different stores? Clue; the answers are percentages
79% ice caps and glaciers 20% groundwater 1% easily accessible surface freshwater
what are the different flows in the water cycle?
-River channel flow - Surface run-off -Infiltration -Percolation - Through flow (driven by gravity) - Stemflow (interception) - Groundwater flow (
what is an aquifer?
saturated, permeable rock that groundwater can flow through
what is the water table?
the upper layer of saturated rock
what is a confined aquifer?
an aquifer that is trapped between both permeable and impermeable rocks. Hence, it is highly pressurised and not affected by drought conditions.
What is an unconfined aquifer?
A aquifer that includes the water table which is at atmospheric pressure and therefore able to rise and fall - hence it is vulnerable to change in drought conditions and due to water abstraction.
what are the stores in the water cycle?
Lithosphere hydrosphere cryosphere atmosphere
Which store does water remain in for the longest?
Deep Groundwater (up to 10,000 years) Ocean (around 3000 or more years)
How long does water remain in glaciers?
20-100 years
which stores hold water for the shortest amount of time?
atmosphere - nine days soil water (1-2 months) rivers - 2-6 months
What is water vapour?
the most common form of atmospheric water which absorbs and reflects incoming solar radiation. It is a greenhouse gas!!!
does warm air or cold air hold more water vapour?
warm air holds more water vapour
How can climate change cause an alteration in the magnitude of water cycle stores?
at the peak of the last ice age the magnitude of cryospheric stores increased. In warmer periods the magnitude of the hydrosphere and atmosphere increases.
Complete this positive feedback loop: - rising sea levels - melting ice shelves
- further rise in sea level
what is evaporation? what is evapotranspiration?
the physical process of liquid becoming a gas - heat energy is needed and transpiration is when liquid is lost from a plant’s stomata. Precipitation occurs when the air reaches its maximum water carrying capacity.
what is condensation?
the physical process whereby gas and water vapour become a liquid. It occurs when air cools and it less able to hold water vapour (known as the dew point). Condensation contributes to the formation of clouds. Precipitation occurs when air can no longer hold the condensed water
what is adiabatic cooling?
when the volume of air increases as it rises and expands but there is no addition in heat - this leads to precipitation
what is orthographic rainfall?
adiabatic cooling - when air is forced to rise over hills and mountains and cools to produce precipitation - the shelter of hills and mountains leads to rainfall only on one side
what is frontal rainfall?
when air masses of different temperatures meet, the warm air rises over the cool sinking air and produces precipitation
what is convectional rainfall?
when warm air rises from hot surfaces on a sunny day
what is accumulation?
inputs into the glacial system due to snowfall
what is ablation?
the outputs of the glacial system due to melting
what is sublimation?
ice changing directly into water vapour
how do storms impact upon the hill-slope water cycle?
intense rainfall infiltrates into the soil less so there is more surface run off - the water reaches the river channel faster and there is more flooding. Less water vapour is held in the atmosphere as intense rainfall takes place.
what is the soil water budget?
the balance of water in a defined area
what happens to the soil water budget in wet seasons?
precipitation exceeds evapo-transpiration so there is a water surplus - ground stores fill with water, more surface run off, higher discharge + river levels rise.
what is river discharge?
the volume of water flowing through a river channel
what happens to the soil water budget in dry seasons?
evapo-transpiration exceeds precipitation so there is a water deficit - ground stores are depleted, there is less surface run off and river levels fall
how does farming impact upon the hill-slope water cycle?
farmers use artificial ditches to drain the land - by improving drainage in poorly drained areas productivity can be improved as soil is aerated and the structure improves. However, this can lead to more through flow and surface run off which increases river discharge and flooding.
more crop cover increases the interception and reduces surface run off
why is the quality of groundwater in coastal areas less reliable?
intrusion of salt water from the sea degrades groundwater and leads to difficulties in using it domestically or for agriculture.
how does urbanisation impact upon the hill-slope water cycle?
impermeable surfaces reduce infiltration and increase the likelihood of flooding
how does deforestation impact on the water cycle?
More water leaves through the channel as less is recycled into the atmosphere through evapo-transpiration. A reduction in water vapour in the atmosphere leads to falling levels of precipitation. River levels fall in the long term. there is less interception and as a result water reaches the river channel faster
what is a drainage basin?
an area of land drained by a river and its tributaries..
what is the watershed?
the boundary between drainage basins
is the drainage basin system an open or closed system?
it is an open system as it has inputs and outputs of both matter and energy
what are the inputs, outputs, and flows in the drainage basin system<
how is water stored in the soil?
pore spaces between soil particles fill with air and water.
describe the soil water budget:
what is discharge measured in?
cumecs
what is a river regime?
the annual variations in the amount of discharge in a river in response to climatic factors and drainage basin characteristics.
what is the lag time on a flood hydropgraph?
the amount of time between the peak rainfall and the peak discharge - it indicates how quickly precipitation reaches the river channel
what is the rising limb?
the part of the hydrograph that indicates how quickly a river responds to a storm event?
what is the falling limb on a hydropraph?
The part of the hydrograph that indicates how a river returns to its base flow after a flood event
would you like to see a hydrograph to study?
Yes, certainly!
what is a flashy hydrograph?
short lag time, high peak, steep rising and falling limbs
what is a subdued hydrograph?
long lag time, low peak rainfall, gently rising and falling limbs,
how does the drainage basin shape affect the response of a river to a storm event?
a circular shape is more flashy because water reaches the channel at the same time
how does the geology of a drainage basin affect the response of a river to storm events?
impermeable rock = more overland flow, less throughflow and less infiltration. = a flashy response.
How does vegetation affect the response of a drainage basin to a storm event?
thick vegetation results in greater interception which slows water accessing the river channel.
evapo-transpiration will also reduce how much water gets into the river which makes the hydrograph more subdued.
how does ground saturation affect the response of a drainage basin to a storm event?
prior rainfall saturates the soil and increases overland flow whilst reducing inflitration
how does water abstraction affect the response of a drainage basin to storm events?
water abstraction reduces the baseflow so more water must reach the channel before it reaches bank-full capacity.
how does afforestation affect the response of a drainage basin to storm events?
interception is increased as evapo-transpiration reduces the amount of water that reaches the river channel.
how does ploughing affect the water cycle?
it creates channels for overland flow
would you like to see a diagram outlining the global water cycle to study the magnitude of different stores?
Yes, certainly!
The Amazon rainforest spans across South America - what percentage of it is in Brazil?
60%
In mm, how much rainfall does the Amazon receive each year?
1,500 - 3000mm
What are the causes of precipitation in the Amazon rainforest?
About half is due to easterlies from the Atlantic
the other half is due to evapotranspiration - due to rapid rising of warm air and sinking of cool air around the equator at the ITCZ.
what is the expected average temperature in a tropical rainforest?
around 27 degrees
what percentage of the world’s oxygen is emitted by tropical rainforests?
28%
how many people live in tropical rainforests and what percentage of the world’s species of plants and animals?
200 million people and about half of all plant and animal species.
what are the impacts of deforestation in the tropical rainforests?
thinking of the water cycle specifically, what are the impacts of deforestation in the tropical rainforest?
- evapotranspiration is reduced, so the atmosphere is less humid
- rainfall reaches the ground immediately, compacting it and encouraging overland flow
- when exposed to the sun, soil will become very dry and vulnerable to erosion
- very little interception of rainfall and transpiration will be minimal.
As a result, there will be increased humidity and lower precipitation on a large scale.
- increased run-off and risk of flooding
in the rainforest, the dense canopy intercepts nearly 75% of all rainfall - where does the rest go?
drips or flows (stemflow) to the ground - to be used by plants, absorbed from the soil or lost through run off.
would you like to see a picture of the tropical rainforest water cycle?
Yes, certainly! 4
In the tropical rainforest cycle, where do plants taken rainwater and nutrients from?
Directly from the soil
In the tropical rainforest cycle, how is rainwater transferred to the forest floor?
by a combination of dripflow and stem flow
In the tropical rainforest, how is water lost?
water is lost through transpiration from pores in the leaves
how will natural variation and human impacts affect storm events in the future?
Storm events will become more intense
As air temperatures rise there will be an increase in the amount of water vapour in the atmosphere. This results in more intense rainfall whereby there is less interception and more flooding
as water vapour condenses into rainfall it releases heat energy which drives more intense storms
what are the effects of farmers introducing artificial drainage systems in agriculture?
Positives;
Improved drainage aerates the soil, can reduce the likelihood of flooding, allows micro-organisms to thrive and reduces compaction from heavy machinery.
Cons:
can artificially create throughflow and increase the likelihood of flooding, the dry surface layer can become prone to wind erosion
what are the consequences of over-abstraction?
Rivers drying up
damage to wetland ecosystems
sinking water tables
empty wells
saltwater intrusion in coastal areas
what is the lithosphere in the carbon cycle?
sedimentary rock deposits (limestone, dolomite and chalk) and fossil fuel deposits.
what is the hydrosphere in the carbon cycle?
describe where and how carbon is stored in the hydrosphere
- surface layer - photosynthesis by plankton
- intermediate and deep ocean - carbon passes through marine food chains and sinks to the ocean bed where it is compacted into sediments
- living and dissolved organic matter
- calcium carbonate in marine shells
what is the biosphere in the carbon cycle?
- organic matter in soils
- plant litter, peat
- organic molecules in living and dead organism
what is the atmosphere in the carbon cycle?
-co2 is a trace gas in the atmosphere - it makes up 0.04% of the atmosphere - but it is a potent greenhouse gas
what are the two largest stores of carbon?
- the deep ocean and sedimentary rocks
The atmosphere is a relatively small stores of carbon - why, then, are we so worried about rising levels of atmospheric carbon?
because carbon held in terrestrial and hydrospheric stores are not problematic - carbon is most potent in the atmosphere and has the biggest impacts - we are concerned about the atmospheric store increasing in magnitude at the expense of other stores
what are carbon pools and fluxes?
pool is another term for a store
fluxes are the processes by which carbon is transferred from one pool to another
describe the ‘fast’ - otherwise known as terrestrial - carbon cycle
- co2 is taken from the atmosphere by plants during photosynthesis
- co2 is then released back into the atmosphere as plants are decomposed and during plant and animal respiration
this cycling is very rapid and known as the fast carbon cycle
describe the oceanic carbon cycle
- carbon is held in a dissolved store within the ocean water
- inputs and outputs take place as a result of gaseous exchange between the ocean and the atmosphere
- further inputs come from the continental run-off of carbon and carbonate ions.
- due to the size of the ocean store, even small changes can have global impacts
describe the atmospheric carbon cycle?
methane and co2 are the primary sources of atmospheric carbon.
methane is more potent but short-lived in the atmosphere
carbon dioxide is cycled through interactions with the terrestrial carbon cycle, e.g photosynthesis, and water absorption
which of carbon dioxide and methane is a more potent greenhouse gas?
which remains in the atmosphere for longer?
methane is a more potent greenhouse gas but does not last for as long in the atmosphere
describe the ‘slow’ carbon cycle which takes place between the atmosphere, rocks and the oceans?
the slow carbon cycle refers to transfer by weathering processes
weathering on rocks on continents by carbonic acid produces carbonate runoff which is transferred to the oceans.
in the ocean the carbonate ions are used to create the shells of marine organisms
- when the organisms die the carbonate sediment produced eventually forms limestone which is released into the atmosphere by volcanic activity in time.
why are we concerned by ocean acidification?
many marine organisms rely upon carbonate ions in the ocean to form their shells
However, increased co2 emissions have led to more absorption in the ocean
this has increased the PH
increased acidity can dissolve the shells of marine organisms and stunt their growth. It also modifies nutrients cycles and has an impact on marine ecosystems, especially Krill in the Southern Ocean.
what are the consequences of increased sunlight for plants?
increased plant growth and photosynthesis
- consequently, greater uptake of co2 from plants
would you like to see a picture to study to carbon cycle at the scale of a single tree?
Yes, certainly!
explain the process of photosynthesis?
plants use energy from the sunlight and combine co2 from the atmosphere with water from the soil to form carbohydrates. Carbon is stored (or sequestered) for long periods of time due to the long lifespan of trees.
describe the process of respiration
plants release co2 back into the atmosphere due to respiration
how does decomposition transfer carbon?
decomposition by fungi and bacteria releases carbon to the atmosphere
decomposition also produces soluble organic compounds which are dissolved in run-off from the land surface
how does combustion transfer carbon?
fossil fuels contain locked in carbon from living organisms over millions of years - the main by-product of burning fossil fuels is co2 which enters the atmosphere
explain the oceanic carbon pump, i.e the cycling of carbon between the ocean and the atmosphere
co2 moves from the atmosphere to the oceans by process of diffusion - at low latitudes, the co2 is absorbed by warm oceans and colder oceans at higher latitudes transfer it into the deeper ocean. Once the ocean is warmed again and returns to the surface it is released to the atmosphere.
how is carbonate removed from the ocean by organisms?
How is it returned to the ocean?
shell binding marine organisms take in carbonate from the ocean to form their shells - when they die the carbonate is released and sinks to the ocean floor where it is compacted into sediment layers.
how is decomposition affected by warm and cold climates?
decomposition is faster in a warmer climate
furthermore, decomposition can be improved by more moisture and precipitation
how do wildfires cause carbon to enter the atmosphere?
- carbon from plants enters the atmosphere in the event of a wildfire
- dense areas of carbon-storing plants are wiped out and there are fewer plants to remove co2 from the atmosphere
- soil is exposed which releases carbon from decaying plant matter
- vegetation is replaced by younger plants which store less carbon than the previous plants.
how do wildfires cause carbon to enter the atmosphere
- carbon from plants enters the atmosphere in the event of a wildfire
- dense areas of carbon-storing plants are wiped out and there are fewer plants to remove co2 from the atmosphere
- soil is exposed which releases carbon from decaying plant matter
- vegetation is replaced by younger plants which store less carbon than the previous plants.
explain how volcanic eruptions can impact on the carbon cycle?
why is the impact of volcanoes on the climate still uncertain?
- volcanic eruptions release large amounts of sulfur dioxide into the atmosphere
- this can reduce the amount of incoming solar radiation
HOWEVER>>>this is often counterbalanced by the absorption of outgoing radiation by the increase in greenhouse gases
SUBSEQUENTLY>>>THE IMPACT ON THE CLIMATE REMAINS UNCLEAR
how does pastoral farming contribute to climate change?
livestock generates methane gas to the atmosphere as a by-product of digestion.
how does ploughing contribute the climate change?
ploughing introduces air into the soil which increases the rate of decomposition, hence more carbon is released into the atmosphere.
how is the rainforest presently a carbon sink?
absorption of co2 by photosynthesis and storage in biomass is greater than the total emissions by respiration
how will deforestation change the rainforest from a carbon sink into a carbon source?
after deforestation has taken place, there will be less absorption by respiration and greater emissions by respiration, burning, decay, and slash and burn.
how does urban growth impact on the carbon cycle?
- urban growth reduces the amount of surface vegetation
- co2 emissions from energy consumption, transport, industry, and domestic use are increased
- there is an increase in co2 emissions from cement manufacture required for building
what is carbon sequestration?
describe the different types?
carbon sequestration is the capture of carbon from the atmosphere and placing it in long term storage
- geological sequestration; this is an artificial process whereby emissions are collected on an industrial scale and piped underground to be placed in long term storage.
- ocean sequestration; as oceans absorb co2, it sinks into deep ocean stores and circulates for thousands of years.
- using plants to capture and store co2 in stems, roots, and soil is known as biological sequestration
what is carbon sequestration?
descibe the different types
carbon sequestration is the capture of carbon from the atmosphere and placing it in long term storage
- geological sequestration; this is an artificial process whereby emissions are collected on an industrial scale and piped underground to be placed in long term storage.
- ocean sequestration; as oceans absorb co2, it sinks into deep ocean stores and circulates for thousands of years.
- using plants to capture and store co2 in stems, roots, and soil is known as biological sequestration
how would a hypothetical state of dynamic equilibrium look in the carbon cycle?
the carbon moving out of any given pool would be the same as the carbon being transferred into that same pool
what is the carbon budget?
the carbon budget is a list of all the carbon pools in existence with an estimate of their size and all the fluxes that contribute inputs and outputs
what does the earth’s carbon cycle tell us?
the system is imbalanced, mainly due to fossil fuel combustion and land use change
what are the two main types of land use change?
deforestation
urbanisation
true or false;
the carbon budget only includes the atmosphere
FALSE!!!!!!!!!!!!!!!!!!!
explain carbon fertilization? why have plants been able to grow faster as-as result of increased carbon?
with more atmospheric carbon dioxide to convert to carbohydrates through photosynthesis, plants have been able to grow more
the amount of carbon that plants take from the atmosphere has increased in recent years.
will plants continue to grow indefinitely with a rise in co2 levels?
plants will continue to grow until they reach a limit in either water or nitrogen
why is the impact of wildfires typically quite restricted?
they can usually be extinguished which prevents large amounts of co2 from reaching the atmosphere
how can intensive agriculture control our carbon emission in some instances?
the use of intensive agriculture has rendered some land surplus to requirements. As a result, it has been allowed to return to dense vegetation which stores more carbon.
what is ocean acidification?
dissolving co2 into the oceans creates carbonic acid, which increases the acidity of the water
fill in the blank;
“the loss of _____ reefs will cause irreversible falls in marine _____”
coral
biodiversity
the enhanced greenhouse effect is warming the oceans - why is this concerning?
because colder oceans have a reduced carbon carrying capacity
how are coral reefs affected by global warming?
ocean warming kills algae, which corals need to grow, leading to bleaching and the eventual death of the reef
what is eustatic change in sea level?
when the sea level changes due to an alteration in the volume of the oceans water
what is driving eustatic change in the oceans? At what rate?
the melting of ice and thermal expansion are altering the volume of the ocean at a rate of 3.5mm per year since 1995.
how do water, carbon and the climate link together?
how do water, carbon and the climate link together?
what percentage of greenhouse gases are from water vapour and carbon dioxide?
70% combined
50% water vapour; 20% carbon dioxide
water vapour is the largest contributor to the greenhouse effect, but not the most important - why is this?
co2 is more significant because it sets the temperature as it affects radiation in the atmosphere.
Subsequently, it can be said that the temperature changes as a result of co2 affect the amount of water vapour in the atmosphere.
complete this positive feedback loop:
- an increase in co2 leads to an increase in the temperature of the atmosphere > warm air holds more water vapour >
> water vapour retains more heat > warmer climate
complete this positive feedback loop;
albedo feedback
warmer climate > snow melts >
> less reflection of sunlight > more warming
what is CCS
carbon capture and sequestration technologies
what are the concerns about geological sequestration? (ALSO KNOWN AS CCS)
- how long will the sequestered carbon remain in storage?
- are there other risks, e.g contamination?
- does the use of ccs discourage us from seeking cleaner alternatives to carbon
- the co2 costs associated with the transport and logistics of CCS could be significant
how long will the sequestered carbon remain in storage?
how can grasslands be improved to absorb more carbon?
minerals and fertilizers can be added to increase organic matter and increase plant productivity which will absorb more co2 from the atmosphere
how can croplands be improved to absorb more carbon?
cash crops can be rotated with cover crops (designed to prevent soil erosion and preserve soil quality) which can add biomass (contains carbon) to the soil.
Forested areas take in co2 from the atmosphere
What % of the earths freshwater entering the oceans comes from the Amazon?
15%
What is the rate of precipitation in the Amazon Rainforest?
Over 2000mm per year
How much carbon (in tonnes) does the Amazon rainforest hold?
Between 80 and 120 billion tonnes
By what percentage has above ground biomass been growing in the tropical rainforest? And why?
Above ground biomass has been growing by about 0.3-05% each year and the rise in productivity levels is down to more sequestering of atmospheric carbon
How much could temperature rise by 2050?
In the Amazon, 2-3 degrees
In terms of throughflow, how do the water and carbon cycle link?
throughflow can only occur in the presence of well formed soil, and good soil structure relies on there being enough Carbon.
In terms of photosynthesis, how are the water and carbon cycle linked?
Photosynthesis converts energy from the sun into chemical energy. It is completely reliant on water.
In terms of decomposition, how are the water and carbon cycles linked?
Decomposition is most effective in moist conditions
How does weathering expose a link between the water and carbon cycle?
How does the water cycle operate independently of the carbon cycle?
The basic processes in the water cycle (evaporation, condensation, flow of water, ) all operate due to the suns energy and gravity, the carbon cycle plays no real role.
What are the feature of the river tees upstream?
surrounded by peat, which becomes saturated with water, and also holds significant stores of carbon.
steep banks around the river allow water to reach the channel quickly, although it is slowed by the peat.
What are the features of the lower course of the Tees?
How does Cow Green Reservoir aid sustainable water supply?
Water can be released into the system at times of shortage to supply domestic and industry users,
water can also be stored at times of high flow to reduce the risk of flooding
Why is the peatland restoration necessary and why is it important?
Drainage channels known as Grips were previously dug to improve drainage and make land suitable for sheep grazing.
HOWEVER, water drained out of here was a tea-like colour caused by Dissolved Organic Carbon (DOC) which leeches from the Peat. It also led to drying out of the soil and weathering.
The Grips needed blocking to resolve this issue - since 2008 68km of moorland grips have been blocked.
