1.c. The carbon and water cycles have distinctive processes and pathways…
1.c. The carbon and water cycles have distinctive processes and pathways that operate within them
Liquid : water -> water vapour
Water transfers latent heat and i released when condensation occurs(eg water from tropical oceans carried into atmosphere to north and south where cooling releases the latent heat)
Vital in transferring water from oceans to land
Diffusion of water vapour from a plant to atmosphere mostly via pores in leaves(stomata)
Contributes 10% atmospheric moisture
Air temp, wind speed water available to plants are controlling factors
Water vapour -> liquid water
Water vapour cools to
, water droplets and clouds appear
Convection: air rises and cools(
Frontal uplift: warm air rises along a air front(
at lower levels and
at high altitudes)
Advection: large mass of air move horizontally over cooler surface, often the ocean. Atmosphere cooled below dew point resulting in
Orographic uplift: air forced to rise over hills or mountains. Condensation may take place if cooling is sufficient
Environmental lapse rate(ELR)
: actual change in temp at given place or time. 6.5oC/km
Dry adiabatic lapse rate(DALR)
:change in temp of a parcel of dry air rising when no condensation occurs. 10oC/km
Saturated adiabatic lapse rate(SALR)
: change in temp of a parcel of air rising when condensation occurs. 7oC/km
Any water that transfers from the atmosphere to the land or oceans, such as rain, snow, hail, sleet or drizzle
Mountainous or high latitude = snow. Frozen water is then stored on surface for several months before it melts and flows through drainage basin
Intensity affects how fast water flows through a drainage basin. High(10-15mm/hour) = rapid surface runoff. Common in tropical rain forests
Duration affects speed of water flow. Persistent hours can lead to fast flows of water whereas rain for 10 mins can be absorbed by soil and plants quickly
Regions may be divided into wet and dry seasons
Temporary storage of precipitation on vegetation or buildings before water reaches surface. Some water evaporates straight into atmosphere. Interception varies considerably depending on season and vegetation.
Buildings are designed to intercept any water that falls on their roofs. Water is channelled by underground pipes to streams and rivers
Infiltration, throughflow, percolation, groundwater flow and run off
Infiltration is the process of water soaking into soil surface. In soil, water moves slowly depending on infiltration capacities. Gravity forces water to move downhill as throughflow. Some moves deeper into underlying rocks by percolation. Gravity moves groundwater flow though rocks
Permeable = water passes through, Impermeable = water does not pass through
Water table = boundary between saturated and unsaturated conditions underground. Rise during high rainfall and low evapotranspiration
Loss of water stored as ice or snow through melting, runoff, evaporation, sublimation, calving of icebergs or the removal of loose snow by wind
In mid-latitude regions, melting is the most important process
CO2 dissolved in rainwater can form weak carbonic acid. This flows back to the ocean due to run off. Affected by rising concentrations of CO2 due to anthropogenic(human) emissions which leads to acid rain. Partly responsible for acidity of oceans
Land plants and marine phytoplankton fix atmospheric CO2 converting light energy into chemical energy
CO2 + H20 -> O2 + glucose
Glucose: building block of cell walls(cellulose), respiration inside plant cells=energy, converted into fats and oils(stores), converted into amino acids used in synthesise proteins
Releases energy through break down of complex molecules such as sugars and CO2 given off back into the atmosphere
glucose + O2 -> H20 + CO2
Vital in fast carbon cycle, exchanging a one thousand times greater volume of carbon than moving through slow carbon cycle.
Carried out by micro organisms(bacteria and fungi) and carbon is released as CO2. Hot, humid climate = fast decomposition while cold, dry climate = slow decomposition
Occurs when organic material reacts or burns in presence of oxygen. Released as CO2
Combustion may occur naturally through lighting strikes starting wildfires and is a key process in maintaining the health of ecosystems. Organic debris that has accumulated in burned which increased carbon and nutrient cycling. New habitats are created.
Humans use combustible materials derived from plants to generate power(eg wood). Biomass fuel is regarded as carbon neutral as when burned, a new plant is already adsorbing CO2 = no net increase.
Combusted oil, coal and natural gas release stored carbon from millions of years ago leading to a net increase in atmospheric CO2
In situ breakdown of rocks at or near the Earth's surface by physical, chemical and biological process. Most involves rainwater(weak carbonic acid).
or solution weathering is the principal chemical weathering process affecting carbonate rocks such as limestones. These are mainly composed of calcium carbonate which is insoluble until reacted with carbonic acid.
calcium carbonate + carbonic acid -> calcium bicarbonate
0.3 billion tonnes of carbon transferred from rock to atmosphere and oceans each year from chemical weathering
Physical weathering = no chemical change to rocks. Results in smaller fragments of rock being broken off which then have a greater surface area to be attacked by chemical. Makes wider cracks allowing more water in(eg frost action)
Biological weathering = action of organic acids.
is a key process in which humic acids attack minerals. Process especially active in tropical rainforest due to warm, humid conditions and plenty decaying organic matter to produce humic acid
Physical (inorganic) pump)
Biological (organic) pump**