Water and Carbon Cycles Flashcards
What is positive feedback and give an example.
Amplify changes in inputs or outputs. Temperature rises Ice melts Less of Sun’s energy reflected by ice More of Sun’s energy absorbed by Earth
What is negative feedback and give an example.
Counteracts change. Large amounts of CO2 emitted CO2 in atmosphere increases Extra CO2 causes plants to increase growth Plants remove more CO2 from atmosphere
Give the three types of precipitation and explain how they come about.
Frontal precipitation - warm air is less dense than cool air, rises above cool air
Orographic precipitation - when warm air meets mountains it rises
Convection precipitation - when sun heats up ground, moisture on ground evaporates and rises, as it gets higher it cools
What is groundwater storage?
Water stored in soil or rock. The water table is the top surface of the zone of saturation, the zone where all soil and rock pores are full of water. Porous rocks that hold water are called aquifers.
When does a water surplus exist?
Wet seasons, when precipitation exceeds evapotranspiration. Ground stores fill with water
When does a groundwater deficit occur?
Drier seasons, when precipitation is lower than evapotranspiration. Ground stores are depleted
Define river discharge
Volume of water that flow in a river per second.
How do farming practices alter the water cycle?
Ploughing breaks up the surface of the soil, increasing infiltration
Crops increase infiltration, interception, and evapotranspiration
Cattle can trample and compact the soil, increase runoff and decrease infiltration
Irrigation can increase runoff and deplete groundwater stores if water is extracted
How does decomposition change the size of carbon stores?
Transfers carbon from dead biomass to atmosphere and soil.
How does ocean uptake and loss affect the magnitude of carbon stores?
CO2 dissolved from atmosphere to oceans, taken up by marine organisms. When carbon-rich water rises to the surface and releases CO2, returning it back to the atmosphere.
How does weathering affect carbon stores?
Transfers carbon from atmosphere to hydrosphere and biosphere. Acid rain dissolves rocks and molecules wash into sea, converted into calcium carbonate and used as shells by marine life.
How do wildfires affect the carbon cycle?
Rapidly transfers carbon from biomass to atmosphere. In the long term fires can encourage growth of new plants.
How does the carbon cycle affect the oceans?
Increased levels of CO2 in the atmosphere can increase ocean acidity along with global warming which can increase ocean temperatures. Phytoplankton may not be able to survive these conditions, less CO2 used for photosynthesis, less removed from atmosphere.
Give an example of negative feedback in the water cycle.
Temperatures rise
Evaporation increases
Amount of water vapour in atmosphere increases, causing clouds to form
Increased cloud cover reflects more of Sun’s energy back into space
Temperatures fall
Give an example of positive feedback in the carbon cycle
Temperatures rise
Plant respiration rate increases
Amount of CO2 in the atmosphere increases
Greenhouse effect increases
