7: Solar (Shortwave) Radiation Flashcards
Top down effect
1) Define
2) What is its affect?
1) Increased incoming UV radiation stimulates O3 formation
2) Slight warming of the stratosphere
Bottom up effect
1) Define
2) What is the affect?
1) Increase in incoming short-wave radiation at surface at the subtropics
2) Increase in evaporation of moisture from the oceans
Wavelength
1) Define
2) Denoted with
1) The distance between two peaks or troughs
2) Lambda
Frequency
1) Define
2) Formula
3) Denoted by
4) In direct proportion to
1) The number of peaks or troughs passing at a given point
2) f = c/lambda
(where c = speed of light)
3) f
4) Energy
Energy
1) Define
2) Formula
3) Denoted by
4) In direct proportion to
1) Energy is the ability of an object to do work
2) E= hc/lambda = hf
(where h is planck’s constant)
3) E
4) Frequency
If wavelength is high what of
1) f
2) E
1) Short
2) Low
If wavelength is low what of
1) f
2) E
1) High
2) High
Electromagnetic Spectrum
From short to long wavelength
Gamma-rays 1 pictometer
X-ray 10-4 micometer
Ultraviolet 0.1 micrometer
Visible 0.4 - 0.7 micrometer
Infrared 1.0 micrometer
Microwaves 1 millimeter
Radio 1 meter
Long wave 1 kilometer
Visible spectrum
Longest wavelength to smallest
Red 780-630 nm
Orange 630-590 nm
Yellow 590-570 nm
Green 570-500 nm
Blue 500-450 nm
Indigo 450-420 nm
Violet 420-390 nm
Visible light Red (780-630 nm) 1) Lambda 2) f 3) E
1) Longest
2) Shortest
3) Lower
Visible light Violet (420-390 nm) 1) Lambda 2) f 3) E
1) Shortest
2) Highest
3) Higher
Blackbody
1) Define
2) Do they reflect
3) Does the perfect blackbody exist
1) Absorbs and emits all wavelengths of electromagnetic radiation
2) NO
3) No
Blackbody
1) Define
2) Do they reflect
3) Does the perfect blackbody exist
4) Two examples
1) Absorbs and emits all wavelengths of electromagnetic radiation
2) NO
3) No
4) Sun & stars
Laws of blackbody radiation
Wien’s Law
1) Define
2) Formula
1) The wavelength of peak emission is inversely proportional to temperature
2) Lambda max = Constant/T
(where constant is Wien’s displacement)
Laws of blackbody radiation
Stefan-Boltzmann Law
1) Define
2) Formula
1) The total energy emitted per unit surface of a blackbody area across all wavelengths is proportional to the 4th power of the body’s temperature
2) E* = Constant x T^4
(Where constant is Stefan-Boltzmann)
Inverse Square Law
1) Define
1) The intensity of emitted radiation decreases by a factor which is the square of the distance
Applying laws: 1. Sun is a lot hotter than earth a) Emits more energy & b) Emits shorter wavelengths 2. Earth is a lot cooler a) Receives a small portion of sun's energy & b) Emits a longer wavelength
- a) Stefan-Boltzmaan law
b) Wein’s law - a) Inverse square law
b) Wein’s law
Energy absorbed (result)
Warming
Energy emitted (result)
Cooling
Why is the sky blue (day)
1) Define
2) Why?
Dust particles in the atmosphere are roughly the same size as the wavelength of blue light
Blue light has shorter wavelength so it gets scattered more (so you see more blue)
Why is the sky blue? (evening & morning)
Shortwave radiation from the sun travels more though space
Now red light get scattered
Why is the sky blue?
How far does it go?
Extends to only 30 km, as most of the dust particles are close to the surface
Albedo
1) Define
2) Albedo of 1
3) Albedo of 0
4) What determines albedo
1) A measure of the reflectivity of the surface of a substance
2) All radiation reflected, lower temperature
3) Everything absorbed, temperature increases
4) By the colour of the surface
Albedo (Darker colour)
1) Albedo
2) Absorption
3) Temperature
1) Low
2) High
3) High
Albedo (Light colour)
1) Albedo
2) Relfection
3) Temperature
1) High
2) High
3) Low
