Jump to content

Archived

This topic is now archived and is closed to further replies.

joo

Snow at Night - Dark or Light?

Recommended Posts

I've been pondering this myself as it was bugging me whilst reading a book.

 

A bloke goes to a lonely hotel in the middle of a snowstorm, the snow is deep on the ground and in the trees.

He's standing in his room when the power goes out and ....... it's really dark.

 

Now I'm sure that if there's snow on the ground, it won't be dark.  I remember some years back when I tested it out my back garden which normally has no light, but the other side of my house looks down into town, so would those lights be reflected off the clouds?

 

So can you help me sort this out in my head in the example above.

 

Would it be very dark out - 

If it's still snowing

If it's not snowing but still cloudy.

If it's not snowing with clear skies, but no moon.

 

Thanks for any answers as I don't want to look silly if I take up this argument.

Share this post


Link to post
Share on other sites

I've been pondering this myself as it was bugging me whilst reading a book.

 

A bloke goes to a lonely hotel in the middle of a snowstorm, the snow is deep on the ground and in the trees.

He's standing in his room when the power goes out and ....... it's really dark.

 

Now I'm sure that if there's snow on the ground, it won't be dark.  I remember some years back when I tested it out my back garden which normally has no light, but the other side of my house looks down into town, so would those lights be reflected off the clouds?

 

So can you help me sort this out in my head in the example above.

 

Would it be very dark out - 

If it's still snowing

If it's not snowing but still cloudy.

If it's not snowing with clear skies, but no moon.

 

Thanks for any answers as I don't want to look silly if I take up this argument.

 

How much light there is during snowfall depends greatly upon your proximity to any light source. So if it snows in a built up area at night and the street lights are on then you'll get a decent orange light from the street lights being reflected back and forth off the snowy sky and snowy ground, almost as if the light becomes trapped at ground level.  If the snow is heavy enough it will become light enough to be able to read a book even away from direct street lights. In this scenario the heavier the snow then the greater the reflection of the light. The effect diminishes the further away you are from street lighting (obviously :) ).

 

If you live far enough away from street lighting then the only other large light source is the moon. Even during heavy snow you may notice a blue glow, but it's not as pronounced as the orange glow street light effect. This blue glow effect will diminish as the snow becomes heavier as the light source is above the clouds/snow, and will be reflected more by thicker cloud/ falling snow before the light reaches ground level. If there's no moon then you'll get little or no blue glow.

 

So in your example at the "lonely hotel" :) we'll assume it's a long way from any other light source so it may become pitch dark during snow but only if there's no moon above the clouds and/or the snow is very heavy.

 

I'm sure others will have their own take on it, but that's my best punt at it :D

Share this post


Link to post
Share on other sites

The reason that it's so light during the night time when there is snow lying is due to the reflective fragments inside snowflakes that reflect light off the cloud.

Share this post


Link to post
Share on other sites

Three answers in and I'm still confused. :D

 

So the whiteness of the ground and trees wouldn't show up if there was no light, but if there's clouds and it's snowing, then it would be lighter?

 

Why do I have this question when there's no snow due to arrive for a few months  :diablo:

Share this post


Link to post
Share on other sites

Pointing out the really, really obvious...snow reflects light, it doesn't generate it. Therefore as catch said, it'll depend on whether there's a light source or not. No light source = dark, snow or not. With a light source then snow will make it seem lighter as it is a better reflector of light than most other surfaces e.g. buildings, vegetation, tarmac.

Share this post


Link to post
Share on other sites

When I was living in the Highlands, where there were few, if any, streetlights nearby, the easiest way of telling when it was snowing was when everything went dark...

 

PS: catch sums it up nicely. :good:

Share this post


Link to post
Share on other sites

I'm glad I asked the question and I thank you all for putting me right.

It is obvious that no light doesn't mean the snow glows on its own accord, but I was assuming that loads of white meant it wouldn't be totally black.

Cheers

Share this post


Link to post
Share on other sites

When I was living in the Highlands, where there were few, if any, streetlights nearby, the easiest way of telling when it was snowing was when everything went dark...

 

PS: catch sums it up nicely. :good:

 

Yes Pete, And that silence! Roll on Winter..

Share this post


Link to post
Share on other sites

From my experience of living in Canada its only 'light' at night when it is actually snowing...if its not snowing even with snow on the ground its still as dark as a night with no snow

Share this post


Link to post
Share on other sites

Full moonlight on snow can make it seem relatively light. Fresh snow has a high albedo. The time-lapse I did Boxing Day night last year, the transformation was remarkable, you can see how "bright" it becomes.

Share this post


Link to post
Share on other sites

A lot depends what your surroundings are.It actually takes 40 mins for your eyes to fully adjust to darkness.If you go out an a white ground and good moon it can be extremely light but if you venture out in blizzard like conditions it can seem very dark and you can get lost easily,i have twice got lost in these conditions and it can be very scarey as you are totally disorientated.Fog and snow is not good either you cannot see a thing,just end up retracing your steps and follow the walls.

Share this post


Link to post
Share on other sites

Everything you see is the colour it because of the part of the spectrum it is attracting. For example a leaf on a tree is green because it is attracting the green part of the spectrum, not because its 'green'.

 

With no moonlight (the sun's reflection of the spectrum) everything is dark, so without 'fake light' everything will be pitch black.

Share this post


Link to post
Share on other sites

Everything you see is the colour it because of the part of the spectrum it is attracting. For example a leaf on a tree is green because it is attracting the green part of the spectrum, not because its 'green'.

 

With no moonlight (the sun's reflection of the spectrum) everything is dark, so without 'fake light' everything will be pitch black.

This isn't quite right. Taking your example Of a leaf, you see it is green because it reflects the green part of the spectrum, not attracts it. This is to do with the pigment called chlorophyll. All other colours are absorbed. However we see different colours in Autumn as the amount of chlorophyll decreases (meaning the leaf creates less food/energy and begins to die) allowing pigments that create reddish colours to come through.

Share this post


Link to post
Share on other sites

×
×
  • Create New...