Term
At what point in time did 60% of all species die out? |
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Definition
At the Cretaceous-Tertiary Boundary |
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Term
What are the impact results of a 10km diameter meteorite? |
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Definition
Blast Wave, vaporization of rock and water, earthquakes, tsunamis, global fires, global darkness, extreme cold, and acid rain. |
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Term
Name diferent types of meteorites. |
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Definition
Stony, Iron, and Stony-Irons. |
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Term
What are the two different types of stony meteorites? |
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Definition
Chrondites and achrondites. |
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Term
Where do meteorites come from? |
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Definition
The main source is from the asteroid belt between Mars and Jupiter but a few dozen also derived from the moon and mars and rarely derive from comets. |
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Term
What causes the formation of meteorites that come from the asteroid belt between Mars and Jupiter? |
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Definition
Collision and fragmentation shifts the orbit of some fragments out of the asteroid belt |
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Term
What causes the formation of meteorites that come from between the moon and mars? |
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Definition
They are most likely the result of an asteroid impact with the moon and mars, sending terrestrial material into space. |
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Term
What causes the formation of meteorites that come from comets? |
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Definition
As the comet gets close to the sun, it sublimates resulting in a cloud of diffuse and fine particles. Comets can split apart when affected by the sun's strong gravitational force. |
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Term
ABout how many new apollo objects are found each year? |
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Definition
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Term
What will all earth-crossing asteroids eventually do? |
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Definition
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Term
How many impact craters our known on our planet? |
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Definition
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Term
What is the closest large impact crater to Michigan? |
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Definition
The 1.8 billion year old 155 mile wide sudbury basin in Ontario, Canada |
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Term
What is the impact sequence of events? |
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Definition
Impact-Mass strikes the Earth and produces shock wave. Compression-SHock wave excavates and compresses material, vaporizing impactor and raising temperature of target rock. Decompression-compressed target rock rebounds. |
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Term
When did the First Primitive Atmosphere develop? |
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Definition
4.6-4.0 billion years ago |
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Term
What was a significant characteristic of the Firt Primitive atmosphere? |
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Definition
It was completely anoxic (lacking oxygen) |
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Term
When did the Secon Chemical/Premicrobal atmosphere develop? |
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Definition
4.0-3.3 billion years ago |
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Term
Why did the composition of the atmosphere change the first time? |
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Definition
Because of volcanic out gassing and perhaps impact degassing of left over planetesimals and cometesimals colliding with earth. |
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Term
What were the temperatures like of the second atmosphere? |
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Definition
Much higher than present temperatures because of high initial temperatures from accretion of planet impacts and also the high amount of carbon dioxide and water of the second atmosphere resulted in a considerable greenhouse effect |
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Term
When and why did the first oceans develop? |
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Definition
3.9-3.8 billion years ago during the second atmosphere when the atmosphere cooled enough for water vapor in the atmosphere to condense to form rain which collected in the ocean basins. the expanding ocean also served as a sink for much of the amospheric carbon dioxide |
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Term
Could life have existed during the second atmosphere? |
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Definition
Life could not have existed within 5M of the ocean surface or on the land because the atmosphere did not provide protection from ultraviolet radiation that disrupts the development of complex molecules such as those of living organisms |
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Term
When did the Third Microbal Atmosphere develop? |
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Definition
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Term
When and what were the first oxygen producing phototrophic organisms? |
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Definition
3.8-3.5 billion years ago procaryote cyanobacteria ("blue-green algae") |
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Term
What was the next step after oxygen producing organisms? |
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Definition
By 1.3 billion years more efficient eukaryotic cells ("green algae") evolved developing oxygen mediating enzymes which are a prerequisite for multicellular, advanced organisms |
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Term
What led to the formation of an ozone layer thick eough to shield plant life within 5m of the ocean surface from harmful effects of UV radiation? |
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Definition
slow buildup of free oxygen in the atmosphere during developmet of the thrids atmosphere |
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Term
When did the Fourth Modern Atmosphere develop? |
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Definition
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Term
What is today's atmosphere composed mainly of? |
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Definition
nitrogen, oxygen, and argon with some carbon dioxide, neon, helium, methane, and hydrogen |
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Term
What is the average thickness of Earth's atmosphere? |
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Definition
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Term
What happens to Earth's atmospheric pressure with elevation? |
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Definition
It decreases exponentially |
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Term
What happens to earth's atmosphereic density with elevation? |
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Definition
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Term
What are the two characters of the sea floor? |
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Definition
oceanic ridges and abyssal plains |
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Term
What is the largest topographic feature on the earth? |
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Definition
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Term
How are black smokers formed? |
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Definition
Hydrothermal vents within central valleys release hot sulfur rich solutions from volcanic rocks. The vents form meter-high dark mounds (black smokers) composed of metal-rich precipitates. |
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Term
Where do abyssal plains lie? |
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Definition
5-6km below the ocean surface and are underlain by fine sediment (mud) |
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Term
What sea floor characteristic form most of the ocean floor? |
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Definition
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Term
Hoe does the thickness of abyssal plains work? |
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Definition
The sediment thins towards the mid-ocean ridges and becomes thicker away from the ridges |
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Term
Types of continental margins |
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Definition
Passive continental margins, active continental margins, special environments |
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Term
What are passive continental margins characterized by? |
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Definition
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Term
What occurs past the continental shelves? |
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Definition
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Term
What are active continental margins characterized by? |
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Definition
narrow to nonexistent continental shelves or by deep ocean trenches |
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Term
What is a characteristic of the special environments within the continental margin? |
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Definition
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Term
What sort of reefs are associated with islands? |
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Definition
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Term
What sort of reefs are associated with continental margins? |
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Definition
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Term
What sort of reefs are isolated and ring shaped and associated with guyots? |
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Definition
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Term
Composition and properties of seawater |
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Definition
Gases, Salinity, Temperature, and Density |
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Term
What are gases in seawater made of? |
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Definition
Mainly oxygen and carbon dioxide |
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Term
Why is dissolved oxygen high in the photic zones? |
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Definition
Due to exchange with the atmosphere and photosynthesis by marine organisms |
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Term
Does oxygen increase or decrease with depth and why? |
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Definition
Decreases due to oxidation of dead organic matter. |
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Term
What doe soxygen do below the depth of 1km? |
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Definition
Dissolved oxygen increases due to convection (circulation) of oxygen rich cold waters from polar regions |
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Term
Why is carbon dioxide low in the photic zone? |
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Definition
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Term
Does carbon dioxide increase or decrease with depth and why? |
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Definition
Increases due to decay of organic matter and high solubility of carbon dioxide in cold waters |
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Term
What is the average ssalinity of the ocean? |
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Definition
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Term
What is salinity in the ocean due to? |
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Definition
mainly dissolved Cl, Na, SO4 and Mg |
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Term
Where is the salinity of the ocean generally least and why? |
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Definition
Near the surface due to dilution by fresh water |
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Term
Does salinity increase or decrease with depth? |
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Definition
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Term
What is the average temperature of the ocean? |
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Definition
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Term
Does temperature increase or decrease with depth and what results from the change? |
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Definition
Decreases often resulting in a warm mixed surface layer 100-200m thick. |
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Term
What temperature lies beneath the surface layer? |
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Definition
A permanent thermocline of unmixed water and a cold layer of unmixed water below that |
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Term
What is the range of density in the ocean? |
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Definition
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Term
What is the density at high latitudes? |
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Definition
It increases to a depth of 300m and then remains generally constant. |
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Term
What does density do in low latitudes? |
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Definition
It increases to a depth of 2,000m and then remains constant |
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Term
What are some examples of surface ocean currents? |
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Definition
The north and south equatorial currents, the west wind current, the north pacific current, and the gulf stream |
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Term
According to the Coriolis and Ekman effects which way is the curviture in the northern and southern hemisphere? |
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Definition
In the northern hemisphere the curviture is to the right, while in the southern hemisphere it is to the left. |
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Term
When are reverse flows possible according to the Coriolis and Ekman effect? |
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Definition
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Term
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Definition
The north atlantic subtropical gyre, the north pacific gyre (Great Pacific Garbage Patch) |
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Term
What are deep-sea currents driven by? |
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Definition
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Term
What causes the density of seawater to increase? |
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Definition
Cooling and freazing in the polar regions |
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Term
What causes the density of seawater to decrease? |
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Definition
High temperatures and large quantities of rainfall in the tropics |
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Term
What causes upwelling of cold waters elsewhere? |
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Definition
Sinking of polar waters displaces deep waters |
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Term
examples of deap-sea currents upwelling |
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Definition
North Atlantic deep water, antarctic bottom water |
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Term
How long does the cycle of upwelling take? |
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Definition
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Term
What is the result of trade-wind currents weakening or reversing late in the year due to eastward shift of the low pressure cell? |
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Definition
Warm surface waters are transported eastward resulting in blockage of upwelling of cold deep water (El Nina) and high precipitation along coast of South America |
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Term
When do effects of El Nina extend far beyond the eatern pacific? |
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Definition
During periods of unusually well-developed blockage ( a strong El Nina event) |
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Term
Examples of El Nina effect |
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Definition
Drought conditions in Western Pacific, heavy rains in Western South America, Southern US and California, and warmer winters in Canada |
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Term
How do tropical cyclones originate? |
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Definition
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Term
Where do tropical cyclones develop? |
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Definition
Along the boundary between the doldrums and the trade-wind belt |
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Term
Of the short-wave radiation intercepted by the Earth's atmosphere, what percent is reflected off air molecules, atmospheric dust, clouds, and the Earth's surface? |
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Definition
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Term
Of the short-wave radiation not reflected, what percent is absorbed by the atmosphere, mainly by ozone in stratosphere? |
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Definition
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Term
Of the short-wave radiation not reflected, what percent is absorbed by the atmosphere, mainly by the Earth's surface? |
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Definition
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Term
the amount of longwave radiation emitted from an object is a function of what? |
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Definition
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Term
What is the temperature of the Earth's surface and atmosphere dictated by? |
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Definition
The balance between incoming and out going radiation |
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Term
What type of radiation is mostly gained or lost at the Earth's surface? |
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Definition
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Term
Is the heat capacity of liquid water relatively large or small? |
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Definition
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Term
Factors driving natural climate change |
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Definition
Atmosphere composition, plate tectonics, orbital variablilty, solar variability, and volcanic eruptions |
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Term
What doe spositive climate forcing lead to? |
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Definition
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Term
What does negative climate forcing lead to? |
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Definition
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Term
What is atmosphere composition connected to? |
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Definition
Changes in concentration of greenhouse gases |
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Term
What is plate tectonics connected to? |
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Definition
Changes in Earth's surface albedo and ocean circulation |
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Term
What is orbital variability connected to? |
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Definition
Changes in received shortwave radiation |
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Term
What is solar variability connected to? |
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Definition
Changes in sunspot activity |
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Term
What are volcanic eruptions connected to? |
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Definition
An increase in the atmospheric albedo |
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Term
WHat are greenhouse gasses connected to? |
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Definition
An increase in atmospheric longwave radition from burning fossil fuels |
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Term
What are anthropogenic aerosols connected to? |
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Definition
An increase in atmospheric albedo from generation of air-born dust |
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