Class Notes for Climate and Climate Change Flashcards
(33 cards)
What does humidity include?
rain and snow
What does wind include?
hurricanes and tornadoes
What are the 5 local climate controls?
1) Latitude
2) Elevation
3) Position in a continent
4) Ocean currents
5) Normal wind direction
What is the role of latitude as a local climate control?
polar (90 degrees latitude) vs equatorial (0 degrees latitude) so it is warmer
What is the role of elevation as a local climate control?
low- near sea level
high- mountains (thinner air so will always be colder)
*Elevation: thinner air at high elevation. Fewer molecules per unit volume, so less to heat up by sunshine; lower heat content – lower temp
How is position in a continent a local climate control?
- sea short (plus or minus 10 degrees celsius)
- interior (plus or minus 10 degrees celsius)
- location of mountains controls rain
- Warmer in the middle of continent than shoreline because ocean has moderating effect. Does not go up and down like the atmosphere.
How do ocean currents control local climate?
move warm water around (plus or minus 5 degrees C)
How do normal wind directions act as a local climate control?
e. g. bring moist air in from ocean
- move air masses
- move sand
- control rain
- dry warm air
The drop in temperature per___m rise in elevation is about the same as an increase of___degrees latitude.
- 300
- 10
Why is the equator warmer than the North pole?
Because the energy is spread over a larger area which is why it is colder
What is the Earth’s tilt (on average)?
23.5 degrees
What are the 6 things that can tell us how warm/cold it was in the past?
- distribution of plant and animal fossils at different geological times
- distribution of ancient glaciers — glacial drift deposits…e.g. tills, moraines. Gas bubbles in modern glaciers — composition of ancient atmosphere…use the CO2 for “O” isotope analysis
- “O” isotope analysis of ancient ice, bubbles in ice, clay from marine muds, fossils from various rocks.
- Historical and archeological information — good for the past few millennia
- Temperature proxies — “O” isotopes, tree width variation
What is the must useful temperature proxy we have
“O” isotope analysis
Besides the 6 reasons, what else must we also know to determine how warm/cold it was in the past?
The absolute age of the material
What was the global average atmospheric temperature at sea level?
15 degrees C
What is the cyclicality for climate?
100 000 years
What was the cycle before the 100 000 year cycle (700 000 years ago)?
41 000 year cycle dominant (tilt)
From___isotopes we can see temp of water in which organisms lived.
O
What was the global average temp for the 1900s?
15 degrees C
Was the temperature cooling or warming from 1800-1940s? What about 1940-1980?
- warming
- cooled for 40 years
- 1980s –> mostly warming
When does tree rings analysis indicate atmospheric warming started?
around 1850
What are the 8 controls on climate change?
1) fluctuations in solar output
2) variations in Earth’s orbital elliptical eccentricity from circle to maximum ellipse–100 000 year cyclicality
3) Variations in tis of earth’s axis
4) Plate tectonics
5) large meteorite (or comet) impacts
6) volcanic eruptions
7) CO2
8) Methane – CH4
How do variations in Earth’s orbital elliptical eccentricity from circle to maximum ellipse–100 000 year cyclicality control climate change?
Earth’ warms because when it is a circle it’s always closer to sun than when it is on its elliptic path.
How do plate tectonics control climate change?
Moves continents into new climatic zones; builds mountain belts
