Lectures 4-6 - Global Radiation

Question 1

Heat

Answer 1

a measure of energy

Question 2

Temperature

Answer 2

a function of the response of an object to the heat or energy absorbed

amount of kinetic energy the molecules possess, rate of vibration

Question 3

Heat capacity

Answer 3

efficiency of conversion of heat to kinetic energy
differs based on material
large heat capacity means it takes a large amount of energy to increase the temp of the substance
specific heat
ex.) winter in Montreal versus in Vancouver (Vancouver is near the ocean and its temp is influenced by the very high heat capacity of the ocean)

Question 4

Conduction/diffusion

Answer 4

heat transfer from faster to slower moving particles

stick touching fire

Question 5

Radiation

Answer 5

emitted by matter as electromagnetic waves due to pool of thermal energy from all matter with temperature
on side of fire

Question 6

Convection

Answer 6

transfer of heat through fluids

hand on top of fire

Question 7

Kelvin to Celsius conversion

Answer 7

T(K) = T(C) + 273.15

Question 8

Habitable zone

Answer 8

optimal area for life given distance from sun

Goldilocks Principle

Question 9

Wavelength and frequency relationship

Answer 9

longer wavelengths have lower frequencies

Question 10

Wave speed equation

Answer 10

c (wave speed) = λ (wavelength) ν

Question 11

photon

Answer 11

elementary particle responsible for carrying the energy of electromagnetic radiation of all wavelengths
􏰀can only interact with matter by transferring the amount of energy given by E = hc/λ
􏰂

Question 12

(Solar) flux

Answer 12

amount of energy or material that passes through a given area
􏰀In the case of the Sun, it is the number of photons that pass through a given area per unit time
changes based on angles –> seasons

Question 13

Inverse Square Law

Answer 13

Radiation spreads out as it leaves its source and the area increases proportionally to the distance traveled
number of photons does not change, they just spread out
S = S0 (r0/r)2

Question 14

blackbody

Answer 14

something that emits or absorbs electromagnetic radiation with 100% efficiency at all wavelengths
has a characteristic wavelength distribution dependent on body’s absolute temperature

Question 15

Planck Function

Answer 15

there will be a wavelength of EMR where flux is maximized

Question 16

Wien’s Law

Answer 16

an approximation of the Planck function
wavelength where maximum flux is emitted is inversely proportional to temperature
λmax≈2898/T where lambda is in micrometers and T is in Kelvin

Question 17

Stefan-Boltzmann Law

Answer 17

energy emitted is proportional to the fourth power of its absolute temperature
F = σT^4

Question 18

Contributors to Earth’s surface temperature

Answer 18

1) solar flux of radiational energy
2) albedo
3) Greenhouse Effect

Question 19

Energy absorbed

Answer 19

equal to energy intercepted - energy reflected
πr^2earthS - πr^2earthSA
The earth absorbs energy as a DISK

Question 20

Energy emitted

Answer 20

4πr^2earth x σT^4sub(e)

emits as a SPHERE

Question 21

Temp of blackbody if it were to radiate what it absorbed

Answer 21

T = fourth root of S(1-A)/4σ

Question 22

Greenhouse gases

Answer 22

H2O (water vapor and clouds), CO2, CH4 (methane), N2O, O3 (ozone)

Question 23

Radiation balances

Answer 23

100 units - top of atmosphere
133 units - surface
154 units - atmosphere

Question 24

Effects of clouds

Answer 24

difficult to quantify
variations in types
variations in coverage
variations in heights and thicknesses