Module 3

Question 1

Temperature radiation heat definitions

Answer 1

Temp is the measure of kinetic energy in a body
Heat is energy in the process of being transferred
Radiation energy in the form of wavelengths emitted by all substances with a temp greater than absolute zero

Question 2

Temp conversion equations

Answer 2

C° to F° (c x 9/5) + 32
F to c (f - 32 ) x 5/9
For k to f just get rid of 273.15

Question 3

Stefan Boltzmann law

Answer 3

Intensity of energy radiated by black body increases with fourth power of absolute temp

Ρ = ε Α σ T^4
P is energy radiated
ε emissivity of substance
A surface area
σ Stefan Boltzmann constant (5.67 x 10^-8 w/m^2K)
T temp in Kelvin

Question 4

Peak emissions def

Answer 4

Wavelength range in which the majority of a substances radiative emissions are found

Question 5

Black body

Answer 5

Theoretical substance that emits 100% radiative energy (100% emissivity)

Question 6

Grey body

Answer 6

Less than perfect emitters
Less than 100% emissivity

Question 7

Emissivity

Answer 7

Percentage of theoretical black body radiative emission that is actually achieved

Question 8

Weins law

Answer 8

For any radiating body the wavelength of its peak emissions is inversely proportional to its absolute temperature

Question 9

Terrestrial and solar radiation wavelengths

Answer 9

Terrestrial:
3-100 um

Solar:
Infrared .8um-1mm
Visible light .4-.8 um
Ultraviolet less than .4 um

Question 10

Global energy budget

Answer 10

Balance between incoming solar radiation and outgoing terrestrial radiation

Question 11

Total solar irradiance

Answer 11

Average amount of insolation received at the top of the atmosphere
11 year cycle due to sunspot activity
Changes in orbital path and position relative to sun
Average TSI = 340 Wm2
Maximum TSI = 1367 wm2
Higher TSI means higher global temps

Question 12

Solar cycle minimums and maximums

Answer 12

Every 11 years suns magnetic poles reverse
At time of reversal suns magnetic field and energy output are at their peak
Solar minimum = point where magnetic fields have stabilised and energy output and magnetic fields are weakest

Question 13

Milankovitch cycle

Answer 13

Reflects changes in orbital path and position relative to sun
Eccentricity: earths elliptical orbital path around the sun due to gravitational effects of other planets pulling earth away from the sun
Increased distance from sun means less energy by inverse square law
Obliquely: the angle or tilt of earths rotational axis which varies from 22.1-24.5 degrees perpendicular to earths orbital plane
More tilt means more severe seasons and less direct light from sun so less energy
Precession: the wobble or rotational path of the earth around its axis of rotation. Wobble is due to the competing gravitational effects of the sun and the moon on the earth as well as the effects of large gas planets Jupiter and Saturn
Very long term and can effect the severity of seasons

Question 14

Equinox and solstice dates

Answer 14

Equinox march and September
Solstice June and December
(23 ° n/s)

Question 15

Processes effecting insolation

Answer 15

Transmission: radiation moves straight through the atmosphere and reaches surface
Absorption: radiation absorbed in atmosphere or by surface
Reflection/scattering: radiation encountering element that redirects its path of motion. When energy is lost this is called diffuse when none is lost it is called specular.
Rayleigh scattering: scattering particles that are small in comparison to wavelength, responsible for blue atmosphere by scattering short wavelengths leaving blue as only visible light during day (blue light scattered 10x more than red light), UV scattered before reaching surface.
MIE scattering: scattering by particles large vs wavelength aerosols or droplets, leads to whitening (cloud color), all wavelength scattered just same manner leaving light blue or grey sky

Question 16

Reaction per 100 units of insolation

Answer 16

Reflection: 30 (20 clouds, 5 atmosphere, 5 surface)
Absorbed by atmosphere: 25 (20 atmosphere, 5 clouds)
Absorbed by surface: 45

Question 17

Why is the sky different colours

Answer 17

Blue and indigo shorter wavelengths and scattered easily by small gas elements
Red and pink require larger elements such as cloud droplets or aerosols
(Sunrise and sunset the light travels a greater distance to get to us so the atmosphere has more time and space to scatter reds and yellows, also blue light effectively used up during the day so reads and yellows make up higher concentration during night)