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General Astronomy => Light Pollution Topics => Topic started by: behelphyri on December 25, 2017, 10:17:19 AM

Title: AAAS Report: 99% US, Europe Pop. under light poluted skies
Post by: behelphyri on December 25, 2017, 10:17:19 AM
Read Full Report Here (http://advances.sciencemag.org/content/2/6/e1600377.full)

<p class="citation">Quote
Abstract
Artificial lights increase night sky luminance, making the very visible effect of light pollution--artificial skyglow.  Regardless of the increasing interest among scientists in areas like ecology, astronomy, healthcare, and land-use planning, mild pollution lacks a present quantification of its magnitude on a global scale.  To defeat this, we now introduce the world atlas of artificial sky luminance, calculated with our mild pollution propagation software using new high-speed satellite data and fresh precision sky brightness measurements.  This atlas shows more than 80% of the world and more than 99% of the U.S. and European inhabitants live under light-polluted skies.  The Milky Way is hidden from more than one-third of humanity, including 60% of Europeans and almost 80% of North Americans.  Moreover, 23% of the world's land surfaces between 75??N and 60??S, 88 percent of Europe, and nearly half of the United States experience light-polluted nights.

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Title: Re: AAAS Report: 99% US, Europe Pop. under light poluted skies
Post by: William Mendoza on December 29, 2017, 05:49:43 AM
Tanx for posting it here--just heard about it on NPR today....
Title: Re: AAAS Report: 99% US, Europe Pop. under light poluted skies
Post by: vicareeti on December 29, 2017, 11:26:57 PM
Also in the report:
<p class="citation">Quote

The atlas also projects what would happen if all outdoor lighting in Europe switched from common high-pressure sodium lights to energy efficient 4000-K white light-emitting dioed (LED) lights. LED lights release more light in the blue part of the spectrum than sodium lights. Those blue wavelengths are more easily scattered by Earth’s atmosphere than other colors, which would considerably increase the light pollution they ultimately contribute, bulb for bulb. Blue light is also more easily picked up by the human eye, which means that people would perceive even brighter skies. The atlas team predicts a doubling in worldwide light pollution if they continue to be adopted globally.
[/quote]

I assume that this assumes that the radiation pattern from light fixtures is the same. This highlights an important mitigation strategy: that LEDs, being inherently directional, are easy to install as directional lights that illuminate areas needing illumination without throwing light in all directions. If light is directed on the ground, there is a 10-fold suppression effect (even more in build-up areas). This increases cost savings by requiring fewer lumens. We need to promote the use of high efficiency directional outdoor lighting.
Title: Re: AAAS Report: 99% US, Europe Pop. under light poluted skies
Post by: Chris Smale on December 31, 2017, 06:02:17 PM
Another report here (http://www.bbc.com/news/science-environment-36492596).
Title: Re: AAAS Report: 99% US, Europe Pop. under light poluted skies
Post by: maulaepretag on January 09, 2018, 02:58:01 PM
I wonder when the very large images will become available so we can use them as a Google overlay. I linked the the original article and the images available where still highly pixelated when you zoom in on a region.
Title: Re: AAAS Report: 99% US, Europe Pop. under light poluted skies
Post by: breakinnocor on January 10, 2018, 02:00:41 AM
So..... I'm finally in the 1%!!!!

While I certainly have noticeable LP at my rural southern NY home (SQM readings around 20.2 or so, with much of the light to my south) I can still see the Milky Way. Friends who live just a few more miles out from the local city get SQM readings of 21.0.

From my Adirondack camp (SQM 21.7)the Milky Wayis bright and dramatic and clouds are just black patches.

Last Sept, during the total lunar eclipse, my landlord sent about 12 people down from his small motel to my camp on the laketo look at the eclipse. These folks were all from 'big city NY'. I gave them my 10x50 wide-field binoculars to look at the eclipsed moon, and then made a mistake...... I pointed out the bright Milky Way. They went nuts..... forgetting all aboutthe lunar eclipse. I had a very hard time getting my binoc's back from them after they gotto scanning from Cygnus to Sag and started seeing all the nebulae and star clusters.
Title: Re: AAAS Report: 99% US, Europe Pop. under light poluted skies
Post by: David Williams on January 11, 2018, 01:10:18 AM
One of the sites that has an interactive map:

http://cires.colorad.../artificial-sky (http://cires.colorado.edu/artificial-sky)

This is very recent data, as the oil/gas fields in the Permian Basin, Eagle Ford and Bakken show up in all their, um, glory.

The resolution is also much better vs. the previous 2006 and 2001 maps.
Clear Skies,
Phil
Title: Re: AAAS Report: 99% US, Europe Pop. under light poluted skies
Post by: Mike Brown on January 11, 2018, 07:40:32 AM
Pink. Is that good? The good news is there is a lot of large dark grey areas within 90 miles of home.
Title: Re: AAAS Report: 99% US, Europe Pop. under light poluted skies
Post by: Jon Venning on January 12, 2018, 10:26:11 AM
At least the media recognizes this.

That's a good sign.
Title: Re: AAAS Report: 99% US, Europe Pop. under light poluted skies
Post by: Cesar Lawhorn on January 12, 2018, 12:49:51 PM
It's tricky to do an apples-to-apples comparison with the older maps because the color zones were all factors of 3 apart from one another, and the the 2006 map was later revised to split each color into two zones 1.73X (square root of 3) apart. The new map has the zones split by factors of 2. For instance, on the old map, the yellow zone was 1.00X - 3.00X brighter than background sky, but the "new yellow" is 1.28X - 2.56X.

The 2006 map was based on the DMSP, if I recall correctly. The latest map is based on the VIIRS data, which is much higher resolution.

One curiosity I had with the 2006 map was the dark-green zone (0.33 - 0.57X) designation for Calhoun County Park, WV, which made no sense. That would made multiple sites in SE Ohio just as dark, and I know for a fact that wasn't the case.

The new map has CCP in the "blue", just darker than the "light blue". The blue zone (as opposed to the new dark blue; yeah, this isn't confusing..) is 0.08X - 0.16X brighter than normal. On the old maps, blue was 0.11X - 0.33X brighter than background. So, maybe 0.15X above background for CCP sounds about right.
It's also interesting to note there's quite a bit of dark green sites (0.32X - 0.64X) in NW Ohio, particularly around Kenton. That's a 2-hr drive from here, but I'd have some interest in scouting this area out when I get the chance, as it would dramatically cut the chances of lake-effect clouds vs. anything in NE Ohio.

Clear Skies,
Phil
Title: Re: AAAS Report: 99% US, Europe Pop. under light poluted skies
Post by: liomocharla on January 13, 2018, 01:48:41 AM
I just put together this map viewer that has a few more options for checking out this data. The data is somewhat low resolution, and in fact will not display once you zoom in passed roughly the county-wide level, but still very interesting.

http://arcg.is/1Pp4fN7 (http://arcg.is/1Pp4fN7)
Title: Re: AAAS Report: 99% US, Europe Pop. under light poluted skies
Post by: Rahul Sanders on January 13, 2018, 02:16:19 AM
Ryan,

Excellent map. It's detailed enough to really nail down where the dark spots are. According to the Science Advances article, the data is very recent -- 2014. This is a MUCH more accurate map than previous versions. VIIRS has much higher resolution (about 7X that of the prior DMSP satellite) and the bright spots correspond very well to locations around my neck of the woods.
One notable deviation from previous maps is Cadiz, Ohio. This small town at the center of Harrison County didn't have much light pollution in 2001 and 2006, but lights from fracking and other related activities (particularly the local processing plant) have bloomed Cadiz into a light dome roughly the same intensity as Zanesville--a city more than 7X its population.

One improvement I wish could be put on maps like this, if in any way possible, would be something that, to the limits of the resolution of the maps, shows the actual sky brightness factor for a selected point on the map.
Clear Skies,
Phil
Title: Re: AAAS Report: 99% US, Europe Pop. under light poluted skies
Post by: percufareg on January 13, 2018, 12:25:27 PM
Phil,
Perhaps I will be able to add that feature to my map viewer when they expand the release of the data. Not possible right now.
Title: Re: AAAS Report: 99% US, Europe Pop. under light poluted skies
Post by: Gandza Startley on January 13, 2018, 01:44:02 PM
It's interesting...
the map seems mainly about the light, when it's light
and particulates that cause the worst trouble...

What do I mean? .... Looking up from next to blazing car dealer lots
and mall parking lots in Bangor, ME (which does show up hot), I could
see far more than looking up from Andover, MA, which is in a hot area,
but also carries a much heavier soot plume from Penn, Ohio, NJ, etc...

I think the particulate pollution has its own effects, when you look at
 higher powers. There is a sort of 'haze bloom' around stars and clusters.

Not to dimish the light factor by any means.
I just think the particulate factor interferes on its own,
and (here vs. Bangor) really boosts the effect of the lights, too.
Title: Re: AAAS Report: 99% US, Europe Pop. under light poluted skies
Post by: Robert Cavalli on January 17, 2018, 08:24:22 AM
Quote
At least the media recognizes this.

That's a good sign.


About time.
Title: Re: AAAS Report: 99% US, Europe Pop. under light poluted skies
Post by: Ivan Deane on January 17, 2018, 11:19:01 PM
Quote
Quote

At least the media recognizes this.

That's a good sign.


About time.
Yeah, it only took all of 50 years.