The water cycle and system frameworks

Flow/transfer: forms a link between one store and another, involving the                                      movement of energy or mass

Input: addition of matter/energy into a system

Dynamic equilibrium: inputs and outputs are balanced in a system, therefore                             store stays the same

Feedback: if inputs increase but theres no change in outputs, the stores change                        and upsets equilibrium

SYSTEMS SHARE COMMON CHARACTERISTICS:

-Structure that lies within a boundary

-Functions by having inputs & outputs of energy/matter - processed within components causing it to change.

Isolated systems: (many just lab experiments, rare in nature)

no interactions with anything outside boundary

no input or output of energy/matter 

Closed systems:

Have transfers of energy both into & beyond system boundary BUT not transfer of matter

Open systems: (eg. eco systems)

matter/energy can be transfered from system across boundary into surrouning environment

Feedback: if inputs increases but no change in outputs, stores change &                                equilibrium is lost

Positive feedback:

effects of action are amplified by secondary effects

(eg. increase in CO2 -> global temp rise -> increase in oceanic temp -> warm water less able to dissolve gases -> more CO2 is released into atmosphere)

Negative feedback: 

effects of action are nulified by secondary effects (eg. use of fossil fuels)

Oceanic water - 72% of earths surface, 97% of earths water

 -salt dissolved in water allows it to stay liquid below 0 celcius (falling due to increase of C)

Cryospheric water - water in solid form (found as)

  sea ice - (Arctic Ocean) formed when water in oceans is cooled below freezing

ice sheets - (50,000km2 or more) eg Greenland. Form over thousands of years of non melting snow forming thick masses of ice 

ice caps - (50,000km2 or less) usually in mountainous regions. The source of many glaciers - they flow outwards (eg. Himalayas, Southern Alps)

alpine glaciers - thick masses of ice in deep valeys - fed by ice from ice caps

permafrost - organic material (soil, rock, ice) that remains below 0 degrees for over 2 years. (most today formed in glacial periods) BUT has begun to melt due to warming climate

Terrestrial water: (surface, ground, soil & biological water)

SURFACE WATER - free flowing water - rivers, ponds, lakes

rivers - acts as store & transfer of water. 

lakes - collections of fresh water found in hollows on earth surface (lake if over 2 hectares)

wetlands - areas where water covers soil all year/varying periods of year, supports aquatic and terrestrial organisms. Vary due to differences in soils, vegetations & human disturbance.

groundwater - water that collects underground in pore spaces of rock. Watertable is level where pores are fully saturated, ground water recharges and flows to surface

soil water - held together with air in unsaturated upper weathered layers of earth very important to hydrological, biological and biogeochemical processes as soil moisture is key variable in controlling exchange of water/heat energy via evaporation.

biological water - water stored in all biomass

Atmospheric water: water is gas, soild & liquid

Gas - scatters/absorbs/reflects solar radiation therefore atmosphere has permenant maintained temperature

cold air cannot hold as much vapour as warm air, therefore poles are dry, tropics are humid

cloud - visible mass of water droplets - result of air in lower layers of atmopshere becoming saturated due to:

              -cooling of air

              -increase of water vapour