Term
| What are the two things climate is affected by? |
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Definition
boundary conditions (settings)
internal processes |
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Term
| What are examples of boundary conditions? |
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Definition
| land/ocean configuration, insolation, Atm composition, Ocean circulation |
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Term
| What are examples of Internal Processes? |
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Definition
| feedbacks and teleconnections |
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Term
| Sources of climate variability can be either _____ or ______ |
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Definition
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Term
| what are the catagories of climate variability? |
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Definition
| periodic (seasons), qausi-periodic (almost predictable such as El Nino,Malenkovich), Random (Volcanism,Younger Drias) |
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Term
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Definition
| permanent ice sheets expand towards the equator. |
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Term
| What was the atm like prior to the precambrian? |
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Definition
| toxic, high levels of CO2 and N |
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Term
| How do supercontinents affect the world climate? |
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Definition
| dry, arid in center of continent, tropical at edges. changes circulation patterns of ocean, decreases it. |
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Term
| What was the climate like 2 mya? |
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Definition
| Gulf stream started up, downwelling maximized, N and S america were connected, ocean currents changed |
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Term
| What caused the Younger Dryas? |
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Definition
| ice dam on east coast retreated, fresh water rushed into the Atlantic. Gulf stream stopped, ice sheets formed |
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Term
| How has the global mean temperature changed over time? |
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Definition
| There has been a narrowing of diurnal temp changes, warmer at night |
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Term
| How has regional variability changed? |
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Definition
| in the high Lat N, warming occurred, interior of the US is cooling |
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Term
| What are problems with Paleoclimate data? |
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Definition
| upper air data is lacking, records not homogenous. |
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Term
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Definition
| human records such as cave paintings, journals, crop records |
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Term
| What are some examples of proxy data? |
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Definition
| Tree rings, settlement patterns from the Norse, Pollen varve, isotopes from ice cores |
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Term
| when global temperatures rise, evaporation is ____, ____ o18 in ice, ___ in ocean sediments. |
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Definition
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Term
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Definition
| a bony earpiece used as a seasonal record of o18/016 isotopes. |
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Term
| what proxy data is used from the sediment record? |
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Definition
| forminerfera - phytoplankton diatoms, record of O isotopes in their area, temp record since diff species live in diff salinities. |
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Term
| Name mechanisms of variability in Forcing Mechanisms |
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Definition
| continental drift, long term solar variations [faint young sun], atm composition |
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Term
| What is the faint young sun hypothesis? |
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Definition
| the sun gave out 30% less output than today, earth same warmth as today starting 3.4 bya. More methane in atm |
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Term
| What events in the Tertiary changed climate? |
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Definition
landmasses in poles, ice sheets build up, cold, high albedo, high temp gradient.
arctic ocean - close off
greenland - closed off
together helped form ice sheets
N hemisphere - panama isthmus, ocean circulation changes. warm atlantic water redirected to E coast, warm water in europe. Overturning current.
- Mtn building - disruption of upper lvl flow, frmt of ice, snow changes |
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Term
| How does the Thermohaline circulation affect CO2 levels globally? |
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Definition
| slow millenial scale downwelling occurs. warm water in high lats, maritime, stores CO2 in the deep water |
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Term
| What happens if the downwelling from the Thermohaline current is blocked? |
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Definition
| over the long term, N. atlantic becomes saltier, warm water cuts across it, high lats get colder, sea ice expands. NW europe goes into cold, dry, ice age. Global temps drop lower |
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Term
| What was the main forcing mechanism during the Pleistocene and Holocene time periods? |
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Definition
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Term
| a large amount of sunspots do what to the suns overall luminosity? |
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Definition
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Term
| What is a random mechanism causing great change in a short timespan? |
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Definition
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Term
| Cloud albedo is an example of what feedback type? |
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Definition
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Term
| the greenhouse effect is an example of what feedback type? |
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Definition
| positive. high temp, more clouds occur, higher temps |
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Term
| Water vapor is what feedback type? |
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Definition
| positive [like the greenhouse] |
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Term
| ice albedo creates what sort of feedback? |
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Definition
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Term
| biological and geophysical events are what kind of feedback? |
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Definition
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