Atmosphere

Layers of the Atmosphere

Layers of the Atmosphere Temperature at 60 km? 60 km ~ -40 oC

Layers of the Atmosphere Thermosphere The Northern Lights occur in this layer Where satellites orbit Mesosphere Meteorites burn up in this layer - a.k.a. shooting stars Stratosphere Ozone layer is found in this layer Troposphere All clouds, breathable air, and weather occur in this layer

Northern Lights

Boundary between the Troposphere and Stratosphere

Composition of Troposphere 78 % nitrogen 21 % oxygen 1 % other gasses greenhouse gasses - absorb long-wave radiation (heat) given off by the earth causing the atmosphere to warm H2O(v) CO2 - volcanoes and burning fossil fuels methane (CH4) – livestock & decaying plant material in water

ozone (O3) layer absorbs UV-radiation The Ozone Layer ozone (O3) layer absorbs UV-radiation Chemicals (CFC’s) destroy ozone creating a hole air conditioners, refrigerators, and in aerosol cans banned in the U.S. and the ozone has began to repair itself.

Energy Transferred In the Atmosphere

Green House Effect Light (short-wave radiation) passes through the atmosphere and is absorbed by the surface of the Earth The surface re-radiates that energy in the form of heat (long-wave radiation) This long-wave radiation is absorbed by greenhouse gases, which heats up the atmosphere Without greenhouse gases the temperature of Earth would be below freezing

Origin and Evolution of the Atmosphere Original atmosphere - outgassing from volcanoes No oxygen was present (stromatolites) used photosynthesis and converted CO2 to oxygen Some of this oxygen reacted with sunlight in the upper atmosphere creating ozone (O3)