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55 Cards in this Set
- Front
- Back
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reasons for cold winters and warm summers
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beam spreading
atmosphere effect length of day |
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beam spreading
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intensity of radiation is effected by the angle the beam makes with thos horizontal surface
the larger the angle of incidence the, the more energy that is spread out on the horizontal surface |
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earth's orbit around the sun
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agle is -23.5 degrees
when angle does not equal -23.5 this increases seasonal change |
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atmospheric effect
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intensity is effected by angle of beam as it passes through the atmosphere
the larger the angle, the greater the distance th beam must travel and the more energy that is lost by the atmosphere's absorption and reflection of the beam |
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2 types of planets
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terrestrial: mercury, venus, earth mars,
other: jupiter, saturn, uranus, neptun, pluto -- less dense -- gas giant planets |
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eath's orbit
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elliptical
closest to the sun at the parhelion (jan. 3) farthest at aphelon (july) |
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environmental change
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fact of our planet's existence
from ice core data we know that temp. and atmospheric comp. have fluctuated job of EAS scientists is to decide whether chances are anthroprogenic or natural |
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natural
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process occurs outside of human society
environmental catastrphies that are not necessarily anthroprogenic - ex: KT boundary: some of the mass extinctions that have occured |
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anthroprogenic
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change is caused by human activities
usually more severe |
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change not understood by scientists
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global warming
we know that the greenhouse effect is caused by burning fuel and deforestation; but due to past fluctuations in temp. we are not sure how much of the warming is caused by this |
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gaia hypothesis
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james lovelock
suggests that life is responsible for keeping earth habitable at least part in spite of perterburtions ex: plants keep atmosphere oxygen-rich |
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human dimensions of global change
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land use/cover
human population |
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land use
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how humans employ land and resources -- anthroprogenic
ex: farming, urban, lumber |
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land cover
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physical state of land surface -- can be natural or anthroprogenic
ex: crops, forests; or spec. characerteristics of soil, etc. important because we need land to grow food best soil tends to be in heaviest populated/urbanized areas |
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climate
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cutting down forests causes CO2 to increase which affects cliamte
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biodiversity
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loss of it related to loss of habitats
ex: loss of wetlands |
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important facts about land change
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1. not always bad; arable land can increase naturally
2. its a natural process |
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land cover info.
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can be natural or antrhoprogenic
can be good not always bad for the environment |
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cultivation/crop lands
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arable land: areas that are cultivated for crops that are replanted after each harvest
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cultivable land
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land that is ice-free -- around 75%
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livestock
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domesticated animals -- non-pets
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types of livestock landcover
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rangeland: use of livestock production constitutes areas that provide forage for free-ranging livestock and wild animals
meadows and pastures: land used permenantly for herbaceous forage crops, either cultivated or growing wild -- wild prarie or grazing land 24% total of ice-free areas |
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forests
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land under natural or planted stands of trees, productive or not, and includes land from which forests have been cleared but that will be reforested in the future
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settlements
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land used for human habitation -- urban/built-up land
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modern extinction
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extinction of large mammals and birds corresponds to human pop. spread
note: africa has a diff. curve because people evolved there with animals |
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human pop. growth over time
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increases linearly for ~9500 yrs and then started growing exponentially about 600 yrs.
rise in population with ind. rev. is paralleled by rise in urbanization regions of world have experienced growth at different times - this relates to when they urbanized |
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malthus theory of human pop.
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will increase geometrically -- double in fixed amts. over time
food supply increases linearly -- pop. will outdo food supply leading to a famine WRONG population doubling time has decreased with time -- super exponential growth rates vary by region -- no famine has occurred |
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demographic transition
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birth rates in agricultural societies are high but death rates are high due to bad med. care and that farming is dangerous
children are 401k -- you need them to take care of you in old age so people have more in urban society, death rates go down since medical care is better there is gap because birth rate stays constant and death rate drops experts predict human pop. will stabalize this century since developing nations will make dem. transition |
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resource price
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more urbanized countries consume more
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stable pop. and fertility rate
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to maintain a stable pop. fertility rate must be 2.1
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metastable equilibrium
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depends on amt. of disruption; stable if disturbed a little, unstable is disturbed a lot
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stable equilibrium
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if system is disturbed, it still returns to original position
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unstable equilibrium
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if dist. if won't return to initial state
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persistent change
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occurs in one direction -- ex: slow decrease of earth's rotation on axis
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period/rythmic change
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follows a sinusoidal variation with set of period oscillation -- ex: waves, tides
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cyclical/oscillatory chance
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like period changes but more random with respect to period and magnitude of oscillation
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singularities
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short-lived events that can cause brief changes from normal conditions
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systems approach/paradigm
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way to conceptualize, analyze, and understand how complex entities operate, evolve, change
system: composed of related parts that make up a whole - components: parts - state: conditions in terms of spec. parameters |
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couplings
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processes that cause various components in system to be interrelated
ex: positive coupling: increasing electric blanket temp causes an increase in body temp negative coupling: body temp. goes up so we decrease the temp. of the blanket |
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feedback loops
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2+ couplings in a system can cause a feedback loop
electric blanket example is a negative feedback loop positive loops: can cause the system to go out of control -- unstable stable system = uneven number of negative couplings multiple together the amt. of negs. and postives and if you get a negative its stable, if you get a positive its not |
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perturbations
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temp. events
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forccings
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more persistent disturbances
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solar luminosity
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radiation from the sun
has increased throughout the history of the earth |
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cold sun paradox/hot sun catastrophe
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sun's outgoing energy has increased with time but earth's temp is constant
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albedo
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reflectivity of any planetary surface
ex: white daisies reflect light -- higher albedo; gray soil absorbs more light -- lower albedo %albedo = reflected light/incident light |
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planetary albedo
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area weighted average of the albedo of each surface type on the planet
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albedo and daisyworld
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daisy coverage increases albedo which decreases climate
-- temp. goes down b/c surface absorbs less energy living organisms have optimum temp. -- parabolic plot -- daisies start dying off after optimum temp is exceeded stable mech.: t is below t optimum unstable: t is above t optimum new eq. is eventually established daisies ended up prolonging their own lives |
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first law of thermodynamics
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conservation of energy
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electromagnetic radiation
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prop. of energy involving coupled electric and magnetic waves
characteristics: w/l - lamda freq - v speep - c radiation also acts as a stream of photons E = hv = hc/lamda h = plack's constant forms are determined by lamda and v |
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radiative flux
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rate at which enery o mass passes though unit area
units of WM^-2 ex: tropic of cancer (23.5 degrees has the greatest amt. of flux also depends on distance from source depends incidence of radiation upon surface and distance from source |
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temperature
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macroscopic property of a substance that describes the ave. amt. of internal energy in the substance
random kinetic energy proportional to ave. velocity of molecules |
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blackbody radiation
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perfect emitter; follows stefen-boltzman; emits and absorbs at all wavelengths with max. efficiency
follows planck, stefan-boltzman, wien's |
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effective temp.
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ave. temp. of a body at which it radiates energy
for planet, its also the temp. the planet would have in the absence of an atmosphere to maintain thermal balance we can calculate this by demanding a simple energy balance energy absorbed = energy emitted |
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energy absorbed by the earth
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eff. area for absorbing radiation is the equiv. a 2-D circle facing the sun
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if albedo does not vary...
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Teff is prop. to (1/r^2)^(1/4)
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