Life support systems - KEY TERMS

What is the importance of water?

Water allows organic molecules to mix and form complex structures, it is the foundation of life itself. On our planet, water creates the moderate thermal conditions required for biological survival. The specific heat capacity of water ensures that it moderates our climate, Many hydrosphere stores such as the ocean, can moderate temperatures by absorbing heat, storing it and releasing it slowly. Water vapour absorbs longwave radiation emitted by the Earth and re-radiates it back to the surface, reflecting approximately 20% of incoming solar radiation, helping to trap heat in the atmosphere. This helps to maintain temperatures 15 degrees above those which would exist without the natural green house gases influence.

What is the importance of carbon?

Carbon is an element with a simple atomic structure that has the ability to bond with other atoms of carbon and also atoms of other elements to create complex molecules which are the basis of all living matter.

Examples of carbons?

Proteins, simple sugars, carbohydrates and fats. These carbon - based compounds are the building blocks of life.

Where is the location and sphere location of carbon dioxide?

Atmosphere, soils and oceans

Where is the location and sphere location of methane?

Atmosphere, soils, oceans and sedimentary rocks

Where is the location and sphere location of calcium carbonate?

Solid compound found in calcareous rocks, oceans, skeletons and shells

What is the location and sphere location of hydrocarbons?

Solids, liquids, gases found in sedimentary rocks

What is the location and sphere location of bio - molecules?

Produced in all living things; in proteins, carbohydrates, fats, oils and DNA

Definition of evaporation

The process in the water cycle that turns liquid water into water vapour, a gas

Definition of condensation

The process by which water vapour turns back into liquid water

Definition of precipitation

Water that falls from the sky in rain, snow, sleet and hail

Definition of stemflow

The flow of intercepted water down a plant’s stem or trunk

Definition of through fall

The portion of rainwater that reaches the soil or litter by falling through gaps in a canopy or leaf drip

Definition of interception (store)

When precipitation lands on vegetation, concrete etc. before it reaches the soil. It is absorbed or is evaporated

Definition of infiltration (flow)

The vertical movement of rainwater through the soil

Definition of percolation (flow)

Water from the soil, moving from the soil into the spaces (pores) in the bedrock

Definition of capillary rise (flow)

The movement of water within the spaces of a porous material due to the forces of adhesion, cohesion and surface tension

Definition of transpiration (flow)

The diffusion of water vapour into the atmosphere from the stomata of plants

Definition of soil moisture (store)

Amount of water stored in soil, excluding lakes and groundwater

Definition of ground water (store)

Water stored in permeable and porous rock underground known as aquifers

Definition of through flow (flow)

Water flowing horizontally through the soil to stream and river channels

Definition base flow (flow)

A portion of the stream flow that is not runoff

Definition of recharge (flow)

Net input of water into an aquifer causing a rise in the water table

Definition of channel storage (store)

The water held in a river or stream channel

Definition of ablation (flow)

The loss of ice and snow, especially from a glacier, through melting, evaporation and sublimation

How are aquifers stored in water?

Vary massively in their ability to store and transfer water. This is mainly due to the size of the pores between the soil particles. For example, sandy nad chalky soils allow water to percolate into the ground

How are aquifers stored in rocks?

Permeable rocks allow more water to be absorbed. Porous rocks have air pockets

Why are aquifers distributed the way they are? - climate

Aquifers are distributed based on climate because areas with higher precipitation lead to greater recharge rates, while arid regions have limited aquifer formation due to lower water availability and evaporation rates. Many of these aquifers are being exploited unsustainably for irrigation which increases the risk of them turning into saline aquifers as sea water can then infiltrate into the rocks. Saline aquifers can increase carbon storage

How much of earth’s water is accessible to humans?

0.03%

What % of our water is stored in oceans?

96.5%

What % of our water is stored in ground ice and permafrost?

69%

How are you doing?

Good

How much of our water is stored in the atmosphere?

3%

What is surprising about the atmosphere only having a minute fraction of the earth’s water?

Despite its small volume, everything in the water cycle system passes through the atmosphere rapidly, its average residence time of a water molecule in the atmosphere is just nine days

An example of a fossil aquifer?

Ogallala Aquifer in Western America

What is the liquid form atmospheric storage?

Droplets from clouds which are formed in low pressure. The distribution of droplets relates to the cloud levels on the three cell model

The global water cycle budget circulates around……

505,000 km2 of water a year

Inputs of water to the atmosphere include…

water vapour evaporating from the oceans, soils and lakes and river. The vapour transpires through leaves of plants. Together these processes are known as evapotranspiration

What are the outputs of the water cycle system?

Moisture leaves the atmosphere as precipitation and condensation. Ice sheets release water by ablation (melting and sublimation)

What is the cryosphere?

Includes all frozen water on Earth, such as glaciers, ice caps, and sea ice.

What is the hydrosphere?

The part of Earth that includes all water bodies, such as oceans, rivers, lakes, and groundwater.

What is the biosphere?

The regions of the surface and atmosphere of the earth or another planet occupied by living organisms

What is the geosphere?

The solid, non-living parts of the Earth, encompassing everything from the surface down to the core

Why is there a latitudinal pattern of global water vapour?

There is most water vapour at the equator as the direct solar energy from the sun causes higher evaporation rates. The warm air has a greater capacity to old moisture, leading to more water vapour. In dry, arid areas there is no water to hold and there is no source of moisture to evaporate up (no oceans)

The average residence time of water in glaciers?

10 to 100,000 years

The average residence time of water in soil moisture?

2 weeks to 1 year

The average residency time of water in ground water: Shallow and deep

Shallow - 100 to 200 years, Deep - 10,000 years

The average residency time of water in oceans?

4000 years

The average residency time of water in the biosphere?

1 week (shortest residency time)

Definition of dew point?

The point at which condensation occurs, after humidity has reached 100% and the air is saturated with moisture.

Simple formation of clouds

Air rises then air cools. When it reaches dewpoint, it condenses. Clouds are then formed and then falls in the form of precipitation

The cause of frontal rain

Warm and cold air meet. The warm air rises as it is less dense. This occurs in the polar front depression

The cause of convection rain

The sun heats the land, the land heats the air above. The air rises because it is less dense and cools and condenses, forming clouds. This occurs in tropical rainforests and links to the 3 cell model because of the movement of air masses driven by the temperature gradients.

What is the cause of relief/orographic rain?

Warm, moist air is forced to rise due to an obstruction of a landform. The air cools and condenses, forming clouds. It rains, then the air descends, warms and becomes drier. This is heavier in the North and West of the UK as it comes into contact with mountain ranges and high lands

What process is responsible for about 10% of the moisture in the atmosphere?

Transpiration

How can the nature of vegetation effect the rate of transpiration?

The adaptations of plants, such as waxy cuticles in deserts reduce transpiration as they adapt to store water in the plant. Furthermore, broader leaves can increase transpiration rates due to a larger surface area for evaporation. Deciduous forests can absorb water more easily whereas coniferous forests are generally more efficient at retaining moisture.

How can humidity levels effect the rate of transpiration

In regions of greater humidity, transpiration decreases due to the lack of diffusion

Cooling due to vertical movement of air: What is convective or adiabatic cooling?

As air rises due to the sun heating the ground, causing air to rise and expand, it cools due to declining air pressure. It cools by itself, leading too no loss of heat due to the surrounding area and occurs without heat exchange with the environment, which is known as adiabatic cooling.

Cooling due to vertical movement of air: What is uplift?

Uplift can occur due to contrasting air masses and cells. Cold, dense air is the obstacle causing uplift. It can also be caused by relief and the land mass

Cooling due to vertical movement of air: What cloud is formed

Cumulus clouds which are long and puffy formations. Due to the sun heating the ground, the heated air parcels rise freely through the atmosphere (convection) and expand and cool. As it reaches the dew point, condensation begins and the clouds form

Cooling due to horizontal movement of air: Advection cooling

When air that was once in a warm area, cools due to coming into contact with a cold area, which is usually a land mass or water body, leading to a decrease in its temperaturw

Cooling due to horizontal movement of air: Radiation (contact) cooling

Occurs when heat is lost through direct contact with cooler surfaces, typically at night, leading to a drop in air temperature. When the dew point is reached, it condenses and causes morning mists and fog and dew

What cloud type forms after cooling due to horizontal movement of air?

Stratiform clouds that are often layered and cover large areas.

Definition of hygroscopic nuclei?

Water molecules tend to remain in a gaseous state until they have surface to condense on. This is a catalyst for condensation, therefore, inducing cloud formation

Definition of relative humidity?

Amount of water vapour as a % of what a parcel of air can hold.

What happens when parcel of air reaches 100% of its relative humidity?

It becomes saturated and condenses, after reaching its dew point.

Definition of environmental lapse rate?

The rate at which atmospheric temperature decreases with an increase in altitude, typically around 6.5°C per kilometer or 1000m

Definition of dry adiabatic lapse rate?

The rate at which an unsaturated air parcel cools as it rises, approximately cooling 10°C per kilometer. As it is less dense, it rises over cold air and continues to rise until it reaches saturation.

Definition of saturated adiabatic lapse rate?

These are for parcels of air that are saturated. It cools less than dry clouds, for every 1km the temperature decreases by 7 degrees. It is influenced by latent heat. This is when condensation releases heat into the atmosphere/ the air parcel, which warms it up in the process of turning vapour into liquid. As it is warmer than the surrounding air, it rises up high.

Definition of absolute instability?

When the parcel of air is warmer than the surrounding air, so it continues to rise

Definition of absolute stability?

If the parcel of air is cooler than the surrounding air. So, you aren’t getting as much of a massive uplift of air which would create cumuliform clouds.

Explain how the global water cycle can be regarding as a “closed system”?

Systems are a group of interrelated components that work together. The global water cycle is a closed system as the total amount of water on Earth remains constant, but the water simply moves between stores such as the ocean and the atmosphere by  processes such as evaporation and condensation. It is recyled. The system is driven by the sun’s energy, which is external to Earth.

What is an artesian aquifer

A “constrained” saturated band of groundwater that is surrounded by impermeable layers of rock in a low lying region which apply pressure to the aquifer, which allows water to be forced out if wells are dug into the aquifer

What is a synclincal structure in an artesian basin

trough-shaped fold in rock