ROUTT ATMOSPHERE

4. Before photosynthesis evolved, the amount of O2 in the atmosphere was ____ ____.
10. movement of air up and down repeatedly in a circular path due to heating and cooling.
11. Above the stratosphere
13. Lowest atmospheric layer
15. The trapping of the sun's warmth by gasses in the lower atmosphere.
17. Above mesosphere
18. comes from volcanism and decay of living things only.
19. tiny droplets of liquid floating in the air.
21. comes from volcanism, decay of living things, burning, animals exhaling.
23. Above the troposphere
24. The atmosphere ____ the Earth.
25. As elevation/altitude increases, air pressure ____.
26. from the Earth deflects particles from the sun that would blast atmospheric gas into space.
27. mixture of gasses surrounding Earth.

1. greenhouse gasses include CO2, ____, H2O, and N2O.
2. tiny solid or aerosol particles, mostly soil particles suspended in the atmosphere.
3. Studies show that since about 1960 CO2 levels have ____.
5. the transfer of energy in the form of heat from a warmer object to a colder object when the objects are in direct contact.
6. the transfer of energy in the form of electromagnetic waves.
7. Density of the atmosphere.
8. the transfer of energy that takes place when warmer air (and other fluids) becomes less dense and rises upwards.
9. O2 comes from this.
12. Photosynthesis is a process used by plants, algae, and some ____.
14. The _____ of the Earth pulls gasses down.
16. An ion is a ____ atom.
20. a gas, O3
22. 21% of the atmosphere