Lecture 2 Flashcards

Earth's Energy Budget

1
Q

weather

A

state of atmosphere at any given time and place

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2
Q

climate

A

average state of climate over some given time interval

typically 30 year weather “normals”

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3
Q

habitable zone

goldilock’s zone

A
  • sweet spot that allows for evolution of complex life
  • strongly controlled by distance from star
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4
Q

stars

A

astral body that emits different wavelengths of EMR

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5
Q

our sun emits…

A

mostly visible light (50%), some as infrared and longwave (40%), and the rest as UV or shortwave (10%)

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6
Q

wavelengths

A

peak to peak

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7
Q

frequency

A

how many waves in a given amount of time (waves/second)

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8
Q

light is measured in ____, and what are they

A

photons
- tiny balls of energy
- smallest amount of discrete energy transported by an EM wave

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9
Q

solar insolation

A

amount of energy passing through a given area over a given amount of time

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10
Q

flux

A

amount of energy (# of photons) in an EM wave passing through a ceratin area/time

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11
Q

solar flux is ____ at the poles because…

A

lower bc there is more area

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12
Q

flux is dependent on …

A

distance from sun and angle of incidence

inverse square law means distance plays even bigger role

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13
Q

eccentricity

A

elliptical orbit
- controls amount of solar insolation received
- 413000 years

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14
Q

precession

A

wobble
- 24000 years

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15
Q

obliquity

A

tilt
- 41000

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16
Q

blackbody

A

ideal absorber and emitter in all wavelengths
- 100% efficiency
- doesn’t actually exist
- but most objects behave similarly

energy in = energy out

17
Q

Planck’s Law

A

relationship between intensity of radiation flux from a blackbody and its wavelength or frequency

18
Q

Wiens law

A

states rad flux from a blackbody reaches its peak at a max wavelength inverse to its absolute temp

the hotter the object, the shorter the wavelength

19
Q

what explains why the sun is yellow

A

Wien’s Law

20
Q

stefan-boltzman law

A

energy flux emitted by a bb is proportional to abs temp ^4

the hotter it is, 4x more flux

21
Q

first law of thermodynamics

A

law of conservation of energy
- when in equilibrium, earth is emitting to space the same amount it is absorbing from sun

22
Q

emissivity

A

thermal radiation emitted from a body’s surface vs the radiation emitted from an ideal blackbody surface at the same temperature

0-1, 1 = perfect emission, perfect blackbody

23
Q

Earth’s energy budget controlled by …

A

incoming/outgoing radiance
- temp of and distance from sun/
- radiated energy and earth’s albedo

24
Q

energy emitted equation

A

stefan-boltzman law and area of a sphere

25
Q

energy absorbed equation

A

energy intercepted - energy reflected
area of a circle and solar constant and 1-albedo

26
Q

important difference between energy absorbed and emitted equations

A

one uses area of a circle one uses area of a sphere

all of earth emits at once, but only half receives sun at once

27
Q

cause of discrepancy between what earth temp should be and what it is

A

greenhouse gases :)

the atmosphere

28
Q

surface temp controlled by

A

○ Solar constant
○ Number of layers in the atmosphere
○ The albedo

29
Q

One layer atmosphere

A

○ Transparent to incoming shortwave
○ Opaque to outgoing infrared
○ Behaves like a blackbody (emits what it absorbs)
○ Energy outwards goes to space and energy down is re-absorbed
- Calculation is too hot

30
Q

N layer model

A

The more layers we have, the higher the temperature goes
- But each layer produces less warming than the last

31
Q

high clouds emit ___ and reflect ___

A

less, less

warming effect, high and cold wispy clouds don’t emit or reflect well

32
Q

low clouds emit ____ and reflect ____

A

more, more

cooling effect, big warm fluffly clouds emit and reflect well