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Variation of EM radiation(Sun) in different latitudes

by thorium1010
Tags: latitudes, radiationsun, variation
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thorium1010
#1
Jul6-13, 10:11 PM
P: 200
So we know that there is variation of EM radiation in different latitudes we receive from Sun. My question is, it same through all EM radiation like uv rays, visible spectrum , IR spectrum or specific to only to one type of radiation like only uv or IR rays? i.e. higher latitude, there is less uv or it is same through all EM radiation we receive ?
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Simon Bridge
#2
Jul6-13, 11:00 PM
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You'll have noticed that the angle to the Sun, at the same time of day, also varies with latitude :)
The amount of radiation received depends on the distance to the source and the amount (and type) of intervening material. Relate that to your question ;)
thorium1010
#3
Jul7-13, 12:26 AM
P: 200
Quote Quote by Simon Bridge View Post
You'll have noticed that the angle to the Sun, at the same time of day, also varies with latitude :)
The amount of radiation received depends on the distance to the source and the amount (and type) of intervening material. Relate that to your question ;)
So angle, meaning it is more perpendicular at the equator than higher latitudes ? Also longer the wavelength the more it penetrates the atmosphere.

So thickness of the atmosphere varies with latitude ?

Simon Bridge
#4
Jul7-13, 01:33 AM
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Variation of EM radiation(Sun) in different latitudes

Lets say the thickness of the atmosphere does not vary with latitude ... draw a circle representing the Earth, and draw another circle around it representing an exaggerated atmosphere thickness ... now draw the rays illuminating this Earth from one side (from a Sun somewhere down the other end of the room) ... observe how much atmosphere must the rays pass through at each latitude in order to reach the ground.

Note: the long-wavelength thing is to do with scattering ... do you generally see a redder sky in the arctic/antactic regeons?
thorium1010
#5
Jul7-13, 05:26 AM
P: 200
what about angle at which the radiation when hits our atmosphere ? Does it play a role in difference in the amount that reaches surface?

Does thicker atmosphere mean more scattering or absorption ?
Simon Bridge
#6
Jul7-13, 08:22 PM
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The angle affects how much atmosphere a ray has to pass through to reach the surface.

A thicker atmosphere means there is more opportunity to scatter and to be absorbed.
EM radiation reduces exponentially with distance through "stuff" while charged particles have a pretty-much fixed stopping distance depending on density of the stuff, as well as the momentum and charge of the particle.
jim mcnamara
#7
Jul7-13, 09:48 PM
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This article on insolation gives background and some more detail to go with Simon's answers.

http://en.wikipedia.org/wiki/Insolation
thorium1010
#8
Jul8-13, 09:51 AM
P: 200
Thanks Simon and Jim.


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