Documents

ATMOSPHERE.docx

Description
ATMOSPHERE The Earth and its atmosphere is the greatest natural system. Solar energy is the input which drives the system. This energy is used, stored and transferred between the Earth and its atmosphere. The output from the system is the energy radiated and lost into space. The atmosphere is an envelope of gases wrapped around the Earth. The gravitational pull of the Earth keeps the atmosphere attached to it. Structure The troposphere is the lowest layer, which touches the surface of
Categories
Published
of 3
All materials on our website are shared by users. If you have any questions about copyright issues, please report us to resolve them. We are always happy to assist you.
Related Documents
Share
Transcript
  ATMOSPHERE The Earth and its atmosphere is the greatest natural system. Solar energy is the input which drives the system. This energy is used, stored and transferred between the Earth and its atmosphere. The output from the system is the energy radiated and lost into space. The atmosphere is an envelope of gases wrapped around the Earth. The gravitational pull of the Earth keeps the atmosphere attached to it. Structure The troposphere is the lowest layer, which touches the surface of the Earth. The base of the atmosphere is warmed by conduction from the Earth's surface so that the temperature falls with increasing height above the ground. The tropopause (divide between troposphere and stratosphere), is reached at -50 C. It is higher in the tropics than at the Poles. Above this in the stratosphere, temperatures begin to rise. Composition of the atmosphere Nitrogen 78.09% Oxygen 20.95% Argon 0.93% Carbon dioxide 0.03% (percentage tiny but really important) The Sun as an energy source Light radiated from the Sun is the source of all energy on Earth. Some absorption takes place in the atmosphere, mainly by gases (18%). Reflection of light back into space occurs from clouds, gases and dust particles in the atmosphere, and from light-coloured surfaces(32%). The remainder(50%) is available for absorption by the Earth's surface. Insolation is the amount of solar energy reaching the Earth's surface that is available as heat. It is higher in the equator and tropics, and lower in the Poles. Alternative energy sources    Water power    Wind power    Solar power Acid rain Clean rain water has a pH value between 5 and 6, which makes it slightly acid. However rainfall in many industrial regions has a pH value of between 4 and 5. The increased acidity comes from the presence of pollutants in the atmosphere, mainly sulphur dioxide and nitrogen oxides. Both are released when fossil fuels are burnt. Causes: road transport, power stations and industries. pH = 7 --> neutral pH > 7 --> alkaline pH <7 --> acid  Damage to the ozone layer The release of a family of chemicals which contain chlorine, the so called CFCs, and halons into the atmosphere are the main causes. CFCs are used as the propellants in aerosols spray cans and refrigeration systems. Halons are used in extinguishers. They are stable, which means that they persist in the atmosphere for a long time. Ultraviolet radiation sets off a chain of chemical reactions in which chlorine converts the ozone into oxygen. This causes the ozone layer to become thinner. Greenhouse effect Water vapour and carbon dioxide absorb most strongly in the long wavelenghts; therefore they mainly trap heat radiation from the land rather than light radiation from the Sun. They also re-radiate some of the heat back to the ground. Cloud droplets also reflect long-wave radiation very effectively. They delay radiation loss commonly called the greenhouse effect. Causes:    burning fossil fuels    deforestation    burning wood    decomposition of waste    rice and cattle farming    use of CFCs in aerosols and refrigeration systems, and release of halons    Fertilizers    Motor transport Effects of global warming    Melting of ice sheets in the Arctic and Antarctica    Rising sea levels    Flooding of low lying coastal areas    Sea defenses breached    Previously populated areas no longer habitable Weather measuring In a weather station we can find:    Anemometer    Wind vane    Rain gauge    Barometer    Max-Min thermometer    Sunshine recorder    Thermometer screen CLIMATES Farming Types:    arable: growing crops    pastoral: keeping and grazing animals    subsistence: growing crops and keeping animals mainly to feed the family     commercial: growing crops and keeping animals for sale    extensive: producing a low output per hectare from large areas of land    intensive: producing a high output per hectare, usually from a small area of land Factors which affect farming    Environmental (weather)    Human (technological, economic and social) Inputs  are what go in the system. Processes  are the activities on the farm which turn inputs into outputs. Outputs  are the end products from farming and the money made from sale. Increased food output and higher yields Farming output had to increase just to keep pace with the growth in world population. Techniques:    Irrigation    Chemicals    Mechanization    Capital    GM crops GREEN REVOLUTION Sustainable agriculture    Irrigation    Organic fertilizers    Mixed cropping    Natural predators    New seeds and plant varieties Biomass Biofuels:  fuels made from crops and mainly used for transport. They are obtained either from vegetable oils or from fermented and distilled products of crops. Fuelwood:  burning wood as a source of energy Biogas:  This is clean methane gas produced from animal ding and other wastes. Climatic hazards    Cyclones: tropical storms which from in the Indian ocean.    Floods: Most caused by rivers breaking their banks after heavy or prolonged periods of rain. Additionally there is coastal flooding due to cyclones.    Droughts: These occur most in the tropics in areas with climates that have a wet season and a dry season.
We Need Your Support
Thank you for visiting our website and your interest in our free products and services. We are nonprofit website to share and download documents. To the running of this website, we need your help to support us.

Thanks to everyone for your continued support.

No, Thanks