1.c. The carbon and water cycles have distinctive processes and pathways that operate within them. Flashcards
What is the water balance equation?
(The processes of the water cycle)
Precipitation = evapotranspiration + streamflow +/- storage
That precipitation is equal to evapotranspiration and streamflow, plus or minus water entering or leaving storage.
What does the water balance equation summarise?
(The processes of the water cycle)
Summarises the flows of water in a drainage basin over time.
What are the 7 principle flows in the water cycle?
(The processes of the water cycle)
Precipitation.
Evaporation.
Transpiration.
Run-off.
Infiltration.
Percolation.
Throughflow.
What is precipitation?
(Precipitation)
(The processes of the water cycle)
Water and ice that falls from clouds towards the ground.
It takes several forms: most commonly rain and snow, but also hail, sleet and drizzle.
How does precipitation form?
(Precipitation)
(The processes of the water cycle)
When vapour in the atmosphere cools to its dew point and condenses into tiny water droplets or ice particles to form clouds.
Eventually these droplets or ice particles aggregate, reaching a critical size and leaving the cloud as precipitation.
Precipitation also varies in character, what does this impact?
(Precipitation)
(The processes of the water cycle)
The water cycle at the drainage basin scale.
What happens to most rain when it reaches the ground?
(Precipitation)
(The processes of the water cycle)
It flows quickly into streams and rivers.
In high latitudes and mountainous catchments, what may happen to precipitation as it falls and reaches the ground? How does this affect the water cycle?
(Precipitation)
(The processes of the water cycle)
Often falls as snow and may remain on the ground for several months.
Thus there may be a considerable time lag between snowfall and run-off.
What is precipitation intensity?
(Precipitation)
(The processes of the water cycle)
The amount of precipitation falling in a given time.
High-intensity precipitation moves rapidly overland into streams and rivers. Why?
(Precipitation)
(The processes of the water cycle)
This is because it is falling at a rate that exceeds the infiltration capacity of the soil.
What is the average speed for high intensity precipitation?
(Precipitation)
(The processes of the water cycle)
10-15 mm/hour.
What is precipitation duration?
(Precipitation)
(The processes of the water cycle)
The length of time that a precipitation event lasts.
How can prolonged precipitation events affect the water cycle?
(Precipitation)
(The processes of the water cycle)
Prolonged events may deposit exceptional amounts of precipitation and cause saturation of the soil which leads to overland flow, and possibly river flooding.
Give an example as to how precipitation varies, and how this affect water cycles.
(Precipitation)
(The processes of the water cycle)
In some parts of the world (e.g. East Africa) precipitation is concentrated in a rainy season.
During this season river discharge is high and flooding is common.
In the dry season rivers may cease to flow together.
What is transpiration?
(Transpiration)
(The processes of the water cycle)
The diffusion of water vapour to the atmosphere from the leaf pores (stomata) of plants.
Transpiration is responsible for what percentage of moisture in the atmosphere?
(Transpiration)
(The processes of the water cycle)
Around 10%.
Transpiration is influenced by what 3 factors?
Temperature, wind speed, and water availability to plants.
Give an example of when plants try and reduce moisture loss through transpiration.
(Transpiration)
(The processes of the water cycle)
Deciduous trees shed their leaves in climates with either dry or cold seasons to reduce moisture loss through transpiration.
What is condensation?
(Condensation)
(The processes of the water cycle)
Condensation is the phase change of vapour to liquid water.
When does condensation occur?
(Condensation)
(The processes of the water cycle)
It occurs when air is cooled to its dew point.
At this critical temperature air becomes saturated with vapour resulting in condensation.
Clouds form through condensation in the atmosphere.
What are the three main types of cloud?
(Condensation)
(The processes of the water cycle)
Cumuliform clouds.
Stratiform clouds.
Cirrus clouds.
What are cumuliform clouds.
(Condensation)
(The processes of the water cycle)
Flat bases and considerable vertical development.
How do cumuliform clouds form?
(Condensation)
(The processes of the water cycle)
When air is heated locally through contact with the Earth’s surface.
This causes heated air parcels to rise freely through the atmosphere, expand, and cool.
As cooling reaches the dew point, condensation begins and clouds form.
What are stratiform clouds.
(Condensation)
(The processes of the water cycle)
Layer clouds.
How do stratiform clouds form?
(Condensation)
(The processes of the water cycle)
Form where an air mass moves horizontally across a cooler surface (often the ocean).
This is known as advection.
What are cirrus clouds.
(Condensation)
(The processes of the water cycle)
Wispy clouds.
How do cirrus clouds form?
(Condensation)
(The processes of the water cycle)
Form at high altitude, consisting of tiny ice crystals.
They do not produce precipitation, and thus have little influence on the water cycle.
Condensation at or near the ground produces what?
(Condensation)
(The processes of the water cycle)
Dew and fog.
Dew and fog deposit large amounts of what?
(Condensation)
(The processes of the water cycle)
Moisture, normally onto vegetation and other surfaces.
Clouds form from condensation at what point?
(Formation of clouds - condensation)
(The processes of the water cycle)
The ‘dew point’.
What is the dew point?
(Formation of clouds - condensation)
(The processes of the water cycle)
The point at which the parcel of air is saturated (started to condense).
8°C.
Clouds form when water vapour is cooled to its dew point. What are the 4 ways in which cooling occurs?
(Formation of clouds - condensation)
(The processes of the water cycle)
1.) Warm air mass mixes with a colder air mass.
2.) Air masses rise over areas of altitude (mountain).
3.) Air masses move horizontally, usually over a cooler surface.
4.) Air, warmed by contact with the Earth’s surface, rises freely through the atmosphere.
What is the term given to air masses that move horizontally?
(Formation of clouds - condensation)
(The processes of the water cycle)
Advection.
What is the term given to air masses that move vertically?
(Formation of clouds - condensation)
(The processes of the water cycle)
Convection.
What do lapse rates describe?
(Formation of clouds - condensation)
(The processes of the water cycle)
The vertical distribution of temperature in the lower atmosphere, and the temperature changes that occur within an air parcel as it rises vertically away from the ground.
What are the three types of lapse rate?
(Formation of clouds - condensation)
(The processes of the water cycle)
Environmental lapse rate, (ELR).
Dry adiabatic lapse rate, (DALR).
Saturated adiabatic lapse rate, (SALR).
Outline the environmental lapse rate, (ELR).
(Formation of clouds - condensation)
(The processes of the water cycle)
The vertical temperature profile of the lower atmosphere at any given time.
On average the temperature falls by 6.5°C for every kilometre of height gained.
E.g. if temp at sea level is 13°C, then 1km into the atmosphere it will be 6.5°C.
Outline the dry adiabatic lapse rate, (DALR).
(Formation of clouds - condensation)
(The processes of the water cycle)
The rate at which a parcel of dry air cools.
Air parcels are less than 100% humidity, so condensation is not taking place.
Cooling is approximately 10°C/km.
This is caused by adiabatic expansion.
Outline the saturated adiabatic lapse rate, (SALR).
(Formation of clouds - condensation)
(The processes of the water cycle)
The rate at which a saturated parcel of air cools as it rises through the atmosphere.
Cooling is approximately 7°C/km.
Cooling is lower than that of the DALR, as condensation releases latent heat.
The process of cloud formation is dependent on what?
(Formation of clouds - condensation)
(The processes of the water cycle)
Geographic location.
When a parcel of air matches the temperature of the surrounding atmosphere, what happens? Why?
(Formation of clouds - condensation)
(The processes of the water cycle)
It stops rising.
This is because it reaches the same temperature, so is not as buoyant; stopping cloud formation.
If a parcel of air is not experiencing condensation, what lapse rate is it influenced by?
(Formation of clouds - condensation)
(The processes of the water cycle)
Dry adiabatic lapse rate, (DALR).
What is atmospheric instability?
(Formation of clouds - condensation)
(The processes of the water cycle)
The expansion of a parcel of air due to a decrease in pressure.
Expansion caused by cooling.
What is a saturated parcel of air?
(Formation of clouds - condensation)
(The processes of the water cycle)
A parcel of air in which condensation is occurring.
What is adiabatic expansion?
(Formation of clouds - condensation)
(The processes of the water cycle)
When air is warmer than surrounding air/ atmosphere, being less dense and therefore buoyant.
If a parcel of air is experiencing condensation (or reached 8 degrees), what lapse rate is it influenced by?
(Formation of clouds - condensation)
(The processes of the water cycle)
The saturated adiabatic lapse rate, (SALR).
Catchment hydrology occurs at what type of system?
(Catchment hydrology)
(The processes of the water cycle)
A local scale system.
What are the 6 processes included within catchment hydrology?
(Catchment hydrology)
(The processes of the water cycle)
Evaporation.
Interception.
Infiltration.
Overland Flow.
Saturation.
Cryospheric processes.
Outline evaporation.
(Catchment hydrology)
(The processes of the water cycle)
Heat is inputted into the system (via the sun).
This heat is then absorbed.
There is a phase change from liquid to vapour.
This vapour then enters the atmosphere.
Outline interception.
(Catchment hydrology)
(The processes of the water cycle)
Carried out by vegetation.
Water/ precipitation is trapped by leaves, trunks, and stems.
Instead, the moisture may either evaporate (a process called interception loss).
Or, it may fall to the ground (a process called throughfall).
During periods of prolonged or intense rainfall, water may reach the ground by flowing down stems or trunks (a process called stemflow).
Outline infiltration.
(Catchment hydrology)
(The processes of the water cycle)
Gravity may cause water to vertically infiltrating into soils.
However, lateral infiltrations of water may also occur - moving water into streams and rivers (a process called throughflow).
Outline overland flow.
(Catchment hydrology)
(The processes of the water cycle)
Water flowing across the ground into streams and rivers.
Outline saturation.
(Catchment hydrology)
(The processes of the water cycle)
Soil may reach infiltration capacity.
This creates saturated overland flow.
Outline cryospheric processes.
(Catchment hydrology)
(The processes of the water cycle)
Ablation by melting, evaporation, and sublimation from snow, glaciers, and ice sheets.
Meltwater is an important component of river flow in high latitudes and mountain catchments.
Rapid thawing of snow in upland Britain leads to flooding in adjacent lowland areas.
What is photosynthesis? How much carbon does it average each year?
The flux of carbon from the atmosphere to land plants and phytoplankton via photosynthesis averages around 120 gigatonnes a year.
How is photosynthesis carried out?
(Photosynthesis)
(The processes of the carbon cycle)
CO2 is present in the atmosphere and water.
Using the Sun’s energy, green plants and marine plankton convert light energy to chemical (glucose) energy.
Plants use energy in the form of glucose to maintain growth, reproduction and other life processes.
Doing so releases CO2, to the atmosphere in respiration.
What are the 3 weathering processes?
(Weathering)
(The processes of the carbon cycle)
Physical, biological, and chemical.
What is carbonation?
(Weathering)
(The processes of the carbon cycle)
When precipitation falls as a weak carbonic acid, and erodes limestone and chalk.
When carbon falls as rain, where is it released to?
(Weathering)
(The processes of the carbon cycle)
Rivers, oceans and the atmosphere.
Chemical weathering transfers how many tonnes of carbon to the atmosphere and oceans each year?
(Weathering)
(The processes of the carbon cycle)
10.3 billion tonnes.
How does freeze-thaw weathering erode rock?
(Weathering)
(The processes of the carbon cycle)
Freeze-thaw involves no chemicals but increases surface area exposed.
Give an example of biological weathering.
(Weathering)
(The processes of the carbon cycle)
Chelation, precipitation mixed with dead, decaying organic matter attacks rocks.
It is most effective in humid, tropical climates.
What is combustion?
(Combustion)
(The processes of the carbon cycle)
When organic material burns in the presence of oxygen.
What does combustion release?
(Combustion)
(The processes of the carbon cycle)
Carbon dioxide.
Why are natural fuel wildfires essential to the health of many ecosystems?
(Combustion)
(The processes of the carbon cycle)
In Winter, decomposition is slow.
Litter builds, and then is burned.
This releases carbon and nutrients.
What is the main cause for burning fossil fuels? How much carbon is released each year?
(Combustion)
(The processes of the carbon cycle)
Human activity clearing land for grazing.
10 gigatonnes per year.
How does precipitation influence the carbon cycle?
(Precipitation)
(The processes of the carbon cycle)
CO2 dissolves rainwater into carbonic acid.
Rising concentrations has resulted in an increase in acidity.
Increased ocean acidity harms marine life.
What is decomposition?
(Decomposition)
(The processes of the carbon cycle)
The process by which bacteria and fungi break down dead organic matter, extracting energy and releasing CO2 to the atmosphere and mineral nutrients to the soil.
Rates of decomposition depend on what?
(Decomposition)
(The processes of the carbon cycle)
Climatic conditions.
Where do the fastest rates of decomposition occur? Give an example.
(Decomposition)
(The processes of the carbon cycle)
Humid environments, e.g. tropical rainforests.
Where do the slowest rates of decomposition occur? Give an example.
(Decomposition)
(The processes of the carbon cycle)
Cold environments, e.g. tundra or drylands.
What is carbon sequestration?
(Carbon Sequestration)
(The processes of the carbon cycle)
The capturing, removal and storage of carbon dioxide (CO2) from the earth’s atmosphere.
What are the two types of pump within the process of carbon sequestration?
(Carbon Sequestration)
(The processes of the carbon cycle)
The physical pump (inorganic).
The biological pump (organic).
Outline the physical pump.
(Carbon Sequestration)
(The processes of the carbon cycle)
Involves the mixing of surface and deep ocean waters by vertical currents, creating a more even distribution of carbon in the oceans.
Outline the role of ocean currents within the physical pump.
(Carbon Sequestration)
(The processes of the carbon cycle)
Initially CO2 enters the oceans from the atmosphere by diffusion.
Downwelling then occurs, carrying dissolved carbon to the ocean depths where individual carbon molecules may remain for centuries.
Eventually deep ocean currents transport the carbon to areas of upwelling.
Now, cold, carbon- rich water rises to the surface and CO2 diffuses back into the atmosphere.
What is downwelling?
(Carbon Sequestration)
(The processes of the carbon cycle)
The process where surface ocean currents transport water (and dissolved CO2) polewards where it cools, becomes more dense and sinks.
Where does downwelling occur?
(Carbon Sequestration)
(The processes of the carbon cycle)
Only occurs in only a handful of places in the oceans.
E.g. North Atlantic between Greenland and Iceland.
Outline the biological pump.
(Carbon Sequestration)
(The processes of the carbon cycle)
Carbon exchanged between the oceans and atmosphere through actions of marine organisms.
Outline the role of marine organisms in the biological pump.
(Carbon Sequestration)
(The processes of the carbon cycle)
Phytoplankton, floating near the ocean surface, combines sunlight, water and dissolved CO2 to produce organic material.
Whether consumed by animals in the marine food chain, or through natural death, carbon locked in the phytoplankton either accumulates in sediments on the ocean floor or is decomposed and released into the ocean as CO2.
Other marine organisms such as tiny molluscs and crustaceans extract carbonate and calcium ions from sea water to manufacture shells and skeletons of calcium carbonate.
Most of this carbon-rich material eventually ends up in ocean sediments and is ultimately lithified to form chalk and limestone.
Globally how much of all carbon fixation is due to photosynthesis within the ocean?
(Carbon Sequestration)
(The processes of the carbon cycle)
Nearly half of all carbon fixation.
How much carbon is drawn from the atmosphere by the biological pump every year.
(Carbon Sequestration)
(The processes of the carbon cycle)
Around 50 GT of carbon.
What does lithified mean?
(Carbon Sequestration)
(The processes of the carbon cycle)
Compressed and compacted into solid rock.
