Transcript of "6.4 condensed characteristics atmosphere review"
Characteristics of the Atmosphere
Characteristics of the Atmosphere• 1. The Astmosphere – a. The atmosphere is a layer of gases and tiny particles that surrounds the earth – b. The study of the atmosphere is called meteorology • i. Meteorologists study • 1. Weather - the general condition of the atmosphere at a particular time and place • 2. Climate - general weather conditions over many years 2
Characteristics of the Atmosphere• 2. Composition of the Atmosphere – a. Most abundant gases • i. Nitrogen = 77% • ii. Oxygen = 21% • iii. Argon = .93% – b. Most abundant compounds • i. Carbon Dioxide- from volcanoes and human activity • ii. Water Vapor- from photosynthesis and transpiration 3
Characteristics of the Atmosphere • 3. Layers of the Atmosphere – a. Troposphere • i. The layer closest to the Earth’s Surface. The Weather Layer • Ii. Closest to earth where water vapor & carbon dioxide are found • iii. Temperature decreases as altitude increases. • iv. Tropopause: zone at the top of the troposphere 4
Characteristics of the Atmosphere • b. Stratosphere (aka the Ozone Layer) i. Atmospheric layer that extends up from the tropopause ii. Almost all of the ozone is concentrated here iii. As altitude increases, temperature increases slightly iv. Heated by UV absorption 5 v. Stratopause: zone at the upper boundary
Characteristics of the Atmosphere • c. Mesosphere i. Atmospheric layer above the Stratosphere ii. The coldest layer, dropping to a temperature of -90 degrees C iii.Temperature decreases as altitude increase iv.Mesopause: upper zone of the mesosphere 6
Characteristics of the Atmosphere • d. Thermosphere i. Atmospheric layer above the Mesopause ii. Temperature increase with altitude iii. Air is to thin, no temperature is known iv. Lonosphere: lower region of the atmosphere v. Exosphere: the zone of indefinite altitude (outer most) 7
Characteristics of the Atmosphere• 3. Atmospheric Pressure – a. Density of the air affects the pressure i. Less dense (lighter weight of air) = lower pressure ii. More dense air = higher pressure a) The atmosphere’s pressure falls as you climb in altitude 8
Characteristics of the Atmosphere• 1. Origin of the Earth’s Atmosphere- Hydrogen & Helium escaped!! a. They are the most abundant elements in the Universe – Because they are small & light, they move fast – Since the earth is so small compared to the universe, Hydrogen & Helium escaped it’s atmosphere long ago 9
Characteristics of the Atmosphere• 2. Outgassing: the atmosphere was built up by release of gasses, mostly from Volcanoes! a. Water vapor and carbon dioxide built up first b. Small amounts of nitrogen were released c. NO oxygen was given off 10
Characteristics of the Atmosphere• 3 Variations in Carbon Dioxide Concentrations – a. In the beginning, carbon dioxide was in abundance – b. Over time, the following changes happened: i. Water vapor condensed to form oceans ii. Carbon dioxide dissolved in oceans and became carbonate rock 11
Characteristics of the Atmosphere• 4. Atmospheric Oxygen Appears… a. Oxygen was released when plants formed b. Plants & algae used carbon dioxide to go through photosynthesis and release oxygen gas into the atmosphere 12
Characteristics of the Atmosphere• 5. Atmospheric Evolution- the atmosphere is dynamic and evolving!! a. Water vapor continues to condense into the oceans b. Carbon dioxide is continuously “locked up” into rocks c. Oxygen is continually formed from photosynthesis in plants d. Human activity (burning fossil fuels and agriculture) changes the atmosphere’s composition 13
Characteristics of the Amtosphere• 1. The Ozone Layer!! a. Ozone forms in the stratosphere b. Ozone is oxygen that absorbs ultraviolet (UV) rays so they don’t reach the ground… this made “life on earth” possible 14
Characteristics of the Atmosphere• 2. Human Activity affects the natural amount of ozone that forms a. Harmful gasses are emitted in large amounts from industry and agriculture b. CFC’s are emitted from other human “inventions” and break down the ozone: refrigerators, exhaust, air conditioners, aerosols c. Small particles replace the oxygen in the ozone layer when released: pollution, volcanic dust, burning of rainforests 15
Characteristics of the Atmosphere• 3. Variation in oxygen (ozone) amounts a. Some natural processes (animals & weathering of rocks) use up oxygen b. Human activity also uses up oxygen – Oxygen is also released by land and ocean plants during photosynthesis – Ozone amounts will remain constant if the amount used up equals the amount produced 16
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