1
Q
definition
PROXY
A
- source of climate information
-from natural and human records
-used to estimate past climate conditions
2
Q
examples
PROXY
A
- human records ie. oral, art, records
- biosphere
3
Q
examples
natural proxies
A
- pollen
- reefs, corals, varves
- stable isotopes
- marine sediment cores
- ice cores
4
Q
stable isotopes
A
- in biosphere proxies
- oxygen molecules that are preserved at the exact time they are trapped
- example: if
5
Q
marine sediment cores
A
- the longest records of past climate
- plankton build calcium carbonate shells that reflect the ratio of heavy and light isotope of oxygen in the sea water where they grew
6
Q
greenhouse and ice house fluxuations
what cycle does it affect and how is it measured
A
- the shift affects the nitrogen cycle
- can be tracked by stable isotopes of N
- snowball earth
- in the phanerzoic
7
Q
greenhouse in mesozoic era
A
- warm late era
- sea level 100-200m higher
- no cryosphere
8
Q
what interval were humans evolved in
A
-cenozoic ice house
8
Q
quaternary period
A
- 2.6 million to present
- the ice age
- has had large glacials and interglacials shown by proxies
- milankivitch cycle
8
Q
holocene epoch
A
- 11,7 k to present
- interglacial interval since the last glacial minimum
9
Q
el nino southern oscillation
A
- ekam transport( counter clockwise in southern hemisphere) causes upwelling
- upwelling is suppressed
- most intense low pressure/rising air shifts west
- warmer temperatures, west pacific is cooler
- releases energy from the ocean into atmosphere
10
Q
la nina
A
- more intense circulation
- enhances upwelling along south america
- steepens thermohaline
- east pacific E cooled
11
Q
forcing
A
- outside effect that changes a flux or reservoir
12
Q
feedback
A
- a system responding to a forcing by enhancing or reducing the forcing
- positive and negative feedback
13
Q
positive feedback
A
system enhances the forcing effect
14
Q
negative feedback
A
forcing changes the system and reacts to reduce the effect of forcing
* EX- radiation of energy reduces earth’s surface temp
* even if there is a positive loop in the cycle it is still considered negative
15
Q
A
EAS100
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