Earth's Life Support Systems Flashcards
Inputs of the water cycle to the atmosphere
To the atmosphere - water vapour evaporated from the oceans, soils, lakes and rivers, and vapour transpired through the leaves of plants - together known as evapotranspiration
Outputs of water to the atmosphere
Moisture leaves the atmosphere as precipitation ( rain, snow, hail) and condensation (fog)
Ice sheets, glaciers and snowfields release water by ablation (melting and sublimation)
Inputs and outputs of water - precipitation
Precipitation and meltwater drain from the land surface as runoff into rivers. Most rivers flow to the oceans through some drain to inland basins. A large part of water falling as precipitation on the land reaches rivers only after infiltrating and flowing through the soil.
Inputs and outputs of water cycle - rocks
After infiltrating the soil, water under gravity may percolate into permeable rocks or aquifers. This groundwater eventually reaches the surface as springs or seepages and contributes to runoff
The slow carbon cycle formation
Co2 diffuses from the atmosphere into the oceans where marine organisms, such as clams and corals, make their shells and skeletons by fixing calcium to form calcium carbonate.
On death the remains of these organisms sink to the ocean floor. There they accumulate and over millions of years, heat and pressure convert them to carbon rich sedimentary rocks
Fast carbon cycle process - organisms
Land plants and microscopic phytoplankton - through photosynthesis they absorb co2 from the atmosphere and combine it with water to make carbohydrate.
Respiration by plants and animals is the opposite process and results in the release of co2. Decomposition of dead organic material by microbial activity also returns co2 to the atmosphere
Fast carbon cycle process - oceans
Atmospheric co2 dissolves in ocean surface waters while the oceans ventilate co2 back to the atmosphere. Through this exchange individual carbon atoms are stored by natural sequestration in the oceans for about 350 years
What are the flows of the water cycle
Precipitation
Transpiration
Condensation
Cloud formation
How does precipitation form
Vapour in the atmosphere cools to its dew point and condensed into tiny water droplets or ice particles to form clouds. Eventually these droplets or or ice particles aggregate, reach a critical size and leave the clouds as precipitation
How can precipitation vary
Most rain flows quickly into streams and rivers - in high latitudes and mountainous areas precipitation may fall as snow and may remain on the ground for several months
Different intensity change speed of runoff
Different duration
Rain seasons
What is transpiration
The diffusion of water vapour to the atmosphere from the leaf pores of plants. It is responsible for around 10% of moisture in the atmosphere
What is condensation
The phase change of vapour to liquid water. It occurs when air is cooled to its dew point. At this critical temperature air becomes saturated with vapour resulting in condensation.
What are cumuliform clouds
Flat bases and consideration vertical development most often form the earths surface. These causes heated air parcels to rise freely through the atmosphere, expand and cool. As cooling reaches the dew point, condensation begins and clouds form
Stratiform clouds
Develop where an air mass moves horizontally across a cooler surface (often the ocean). This process is known as advection
Cirrus clouds
Form at high altitudes and consist of tiny ice crystals. Unlike cumuliform and stratiform clouds they do not produce precipitation and therefore. Have little influence on the water cycle
