8. Steps for heating the atmosphere: 1) Short wavelength solar radiation passes through atmosphere (uv & visible range) 2) Earth’s surface absorbs solar radiation & heats up
9. Steps for heating the atmosphere: 3) Earth emits infrared radiation 4) CO2 & H2O vapor absorb infrared radiation - “selective absorbers”
10. Earth-Sun Relations Causes annual variations in seasons at a given latitude Rotation = Earth spins on axis Revolution = Earth’s elliptical orbit around sun
11. Earth’s axis: Tilted 23 ½ o off vertical to plane of the ecliptic - points to North Star Most intense sunlight = solar rays striking Earth’s surface at 90o
12. Earth-Sun Relations Know for each season: 1) date 2) location of vertical rays of sun 3) nickname
13. Controls of Temperature 1) Latitude controls: a) Intensity = sun angle Most intense = 90o Lower sun angles = less intense
14. Latitude b) Amount = length of daylight hours At night, Earth emits radiation w/o collecting anymore - coolest temp. = _____________
15. Latitude Summer vs. Winter More daylight hours = Earth builds up surplus of energy (hot temp’s) Less daylight hours = Earth loses more energy than it gains (cold temp’s)
16. Latitude Affects annual temperature range i) Closer to equator = ____ annual temp. range ii) Closer to poles = _____ annual temp. range Why?
19. Cloudy vs. Clear Nights Cloudy night: Daily temp. range is__________ Clear night: Daily temp. range is __________
20. Controls of Temperature 3) Land vs. water ____ heats more in summer Land cools more in winter Land has more variable annual temperature range than water
21. Controls of Temperature 4) Elevation – land height above sea level Cooler temp’s at higher elevations b/c: a) Further from main heat source (“radiator”) = Earth’s surface