7: Solar (Shortwave) Radiation
No description yet. This curated deck is ready for daily study.
Card preview (24)
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