BIOC58: Climate Change (Midterm) Flashcards
the impact of climate change on natural systems, with a focus on future impacts of anthropogenic climate change
climate change biology
founders: Rob Thomas & Peter Lovejoy
interactive system consisting of 5 major components and the impacts of forcing mechanisms on these components
climate system
what is the greenhouse effect?
- earth’s surface radiats long-wave radiation back into space
- GHG absorb and re-emit some of this long-wave radiation
- radiation that would have escaped to space is re-radiated w/in the atmosphere, causing warming
what are the 2 most abundant GHG in the atmosphere?
- water vapour
- carbon dioxide
what happens in a region with cloud cover (clouds present)?
- cooler days (sun’s energy reflected back to space)
- warmer nights (head from ground is trapped)
what happens in a region with no cloud cover (absence of clouds)?
- warmer days (more energy from sun reaches earth)
- cooler nights (heat doesn’t get trapped)
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B) When temperatures increase, this can slow down the water cycle due to decreased evapouration, which can influence climate patterns
- should be increased evapouration
the amount of solar energy reflected by a surface
albedo
(white = 1, black = 0)
- light surfaces reflect sunlight back into space in wavelengths not trapped by GHG = cooling effect
- dark surfaces re-radiate heat that can be trapped by GHG
what are the 5 major components of the climate system?
atmosphere: 78% N, 21% O, GHG
hydrosphere: water/water movement (hydrological cycle) and clouds
cryosphere: ice and snow
land surface: vegetation, soil, rock
biosphere: where all life on earth can exist
the amount of solar radiation that reaches the earth’s surface
(direct) insolation
the amount of solar radiation lost to the atmosphere or the presence of clouds
diffuse insolation
how is insolate measured?
hint: what are the units used?
cm2/min
or W/m2
or KW/m2
when warm air rises because it’s less dense than cool air
uplift
phenomenon where as air it cools, it becomes more dense and it sinks
subsidence
a zone of low pressure where trade winds meet
intertropical convergence zone (ITCZ)
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large scale circulation patterns resulting from tropical uplift
Hadley cells
when cold air descends and creates high pressure zones
Polar cells
mid-latitude cells, driven by movement of air in Hadley and polar cells
Ferrell cells
when winds appear to deflect due to the earth’s rotation around its axis and shape
think of a ball being thrown on a spinning merry-go-round
Coriolis effect
winds deflect RIGHT In th NORTH, LEFT in the SOUTH
air flows from _____ pressure to _____ pressure, producing _____
air flows from HIGH pressure to LOW pressure, producing prevailing winds
trade winds blow from _____ and meet at the ITCZ
westerlies blow from _____ and balances trade winds
trade winds blow from EAST to WEST and meet at the ITCZ
westerlies blow from WEST to EAST and balances trade winds
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why do hurricanes spin counterclockwise? how does this relate to the coriolis effect?
- hurricans have low pressure in the center and surrounded by high pressure systems
- winds try to move to the center
- in N. hemisphere, winds deflect right and spins CCW
- in S. hemisphere, winds deflect left and spins CW
continually replaces seawater at depth with water from the surface and slowly replaces surface water elsewhere with water rising from deeper depths
thermohaline circulation
aka the Great Ocean Conveyor Belt
when surface winds push ocean currents but water currents move slower, resulting in a different deflection (by 15oC – 45oC)
Ekman spiral
how much of the heat exchange b/w tropics and polar regions occur through ocean currents?
40%
60% Is from wind movements
when prevailing winds blow warmer surface water away from coast and deeper, colder, nutrient-rich water rises up to replace it
upwellings
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the warm and cool phases of a recurring climate pattern across the tropical Pacific
El Niño-Southern Oscillation (ENSO)
El Niño and La Niña
a warming of the ocean surface in central and eastern tropical Pacific ocean
- results in increased rainfall
- trade winds can weaken or start blowing in other direction
El Niño
how do volcanic eruptions affect climate change?
- when volcanoes erupt, they release a mixture of gases and particles into the air
- some of these particles can reach the stratosphere and reflect sunlight away from the earth = colder temp.
the earth is farthest from the sun in _____ and closest in _____
the earth is farthest from the sun in JULY and closest in JANUARY
shape of orbit around the sun
eccentricity
the amount of earth’s tilt
obliquity
the direction of earth’s tilt relative to other celestial objects (not the sun)
precession
what are the 3 orbital forcings?
- eccentricity
- obliquity
- precession
what do orbital forcings impact?
they impact the distribution of solar energy across earth b/w seasons and b/w hemispheres
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D) loss of seasonal changes