¥Thermosphere: highest layer, (also
called ionosphere), merges with space gradually, temp. increases with altitude heated by
cosmic rays
¥Mesophere:
below thermosphere, extends to altitude of ~80 km (50 mi), grows cooler with increasing altitude
¥Stratosphere: below mesosphere, contains protective Òozone
layerÓ absorbs much of SunÕs harmful uv radiation,
extends to ~50 km (31 mi), hotter with increasing altitude, small amounts of ozone
vital for photosynthesis, BUT intense uv damages living
tissue
¥Troposphere:
atmospheric layer closest to Earth surface, this is where weather happens, becomes colder with increasing
elevation, 8 km (5 mi) in Polar regions, up to 17 km (10.5 above equator, layer
where greenhouse gases are trapped and where global warming
occurs.