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Sci - Atmosphere
Includes: Atmosphere notes-1.1; BrainPOP-Atmosphere and Ozone movies
Question | Answer |
---|---|
atmosphere - early makeup | -made by erupting volcanoes; nitrogen, CO2, little O2; 2 billion yrs ago-life in oceans=O2,deep enough in H2O until O3 made |
atmosphere - current makeup | nitrogen=78%, oxygen=21%, 1%=argon(0.93)+carbon dioxide (0.03); trace gases= neon, krypton, methane, helium, xenon, ozone; water vapor=4% |
solids and liquids in atmosphere | small solids= dust, salt, pollen; liquid droplets and solids from volcanoes etc. |
pressure | force exerted on an area; gravity pulls molecules above; molecules close to surface=lots of pressure; mountains=higher=less O2=hard to breath; jets in stratosphere=need pressurized cabins |
troposphere | ~10km thick, densest layer,8km at poles, 16km at equator; 99% water vapor+75% gases; has weather+ small planes; steepest air pressure drop; temp decreases 6.5 degrees=up per km,land warms air |
stratosphere | ~40km thick,jets, weather balloons; has ozone layer=blocks UV rays + gives energy to molecules |
mesosphere | ~35km thick, meteors burn; temp decrease; has part of ionosphere=reflects AM radio waves at night - Sun=interacts w/ waves=waves aborbed |
thermosphere | ~415km thick (goes to 500km); warm+thick; few molecules, but sun energy |
exosphere | very few molecules; shuttle orbits - need rocket thrust to move-wings=useless |
ozone in atmosphere | blocks most of UV from Sun |
chlorofluorocarbons (CFC's) | from aerosols, fridges, A/C's = destroy ozone; UV breaks CFC, Cl then breaks O3, leaving O2; 1 chlorine atom destroys 100,000 ozone molecules |
ozone hole over Antarctica | 70% ozone lost by 1980's; Montreal Protocol 1987: 16 countries but now 190+ ban CFC's; use EPA certified technicians |