Trixology

Weather => General Weather Discussion => Topic started by: idunn on November 17, 2016, 03:42:53 PM

Title: Anybody ever seen the Green Flash?
Post by: idunn on November 17, 2016, 03:42:53 PM
Greetings all,
Got thinking about the Green Flash while looking at the last seconds of the sunset in Berkeley.  Have any of you ever seen one?  You can read about it at https://en.wikipedia.org/wiki/Green_flash
Attached is the view from the UC Berkeley webcam  http://static.lawrencehallofscience.org/scienceview/scienceview.berkeley.edu/html/view/index.php
You can stop and start the video with the mouse and so catch the Green Flash moments. Just wonder how often it occurs.
I plan to check for it on this video in the future.
Regards, Irving
Title: Re: Anybody ever seen the Green Flash?
Post by: vetenskapsman on November 17, 2016, 08:21:51 PM
Hi Irving,  Green Flashes are really cool.  Here is a tally of my sightings.

Number of times I have purposely tried to look for Green Flash:  est >100

Number of times I have sorta kinda (meaning probably not) seen one:  ~5-6

Number of times I have actually, really, really, pretty sure seen one:  2

Number of times I have photographed one:  0 (I have lots of pictures of "empty" sunsets  :-[)

Both times I have seen them have been on the ocean horizon. One on Santa Barbara coast and another in Baja.  The problem for me is you are looking at the setting sun and which is still pretty bright and when the time comes you can sort of convince yourself that you saw another color which I think can be confused with an afterimage.

Despite my low success rate I don't think they are all that rare really.  I think it happens more often than one might think it's just people aren't looking for it or notice it for what it is.  Good idea to use a webcam - though it might be a little hard with the wide field of view.  That offshore marine layer probably won't help with the chances but on clear days certainly worth a shot.

Now that I live in the high desert I won't get as many opportunities (no ocean).  But one over land would be pretty cool so I'll keep trying when the situation presents.

-carl
Title: More memories (Re: Anybody ever seen the Green Flash?)
Post by: elagache on November 17, 2016, 11:38:49 PM
Dear Irving, Carl, and WeatherCat sky watchers,

Quote from: idunn on November 17, 2016, 03:42:53 PM
Got thinking about the Green Flash while looking at the last seconds of the sunset in Berkeley.  Have any of you ever seen one?

I've never seen one, but it was one of those things I learned about when I first got interested in Astronomy.  The book that got me hooked was The Sky Observer's Guide.  It was in our local library in the early 1970s, but the book is still in print today:

https://www.amazon.com/Observers-Guide-Golden-Martins-Press/dp/1582381550 (https://www.amazon.com/Observers-Guide-Golden-Martins-Press/dp/1582381550)

The green flash is covered in the chapter called "Sky Colors."  I still have a copy and I just flipped through a few pages.  Wow!  The memories!

Cheers, Edouard  [cheers1]
Title: Re: Anybody ever seen the Green Flash?
Post by: idunn on November 18, 2016, 08:44:41 AM
I read about the green flash in a Jan. 1960 Scientific American (googled it).  I think it was not until around 1980 that I managed to see it on a beach in Portugal. As I was watching, the sun went behind a cloud and came out underneath with the green flash. Nothing since then though. So only one time out of hundreds of tries. It is worth waiting for.
Irving
Title: Re: Anybody ever seen the Green Flash?
Post by: idunn on November 18, 2016, 09:16:56 PM
I found a very instructive Youtube video on the green flash.  The images were taken through a small telescope.  Don't miss it!
https://www.youtube.com/watch?v=LWw8z75AXwU
Irving
Title: Re: Anybody ever seen the Green Flash?
Post by: Blicj11 on November 19, 2016, 04:18:25 PM
Interesting video. Thanks for sharing.
Title: Re: Anybody ever seen the Green Flash?
Post by: xairbusdriver on November 19, 2016, 10:28:10 PM
More "Fake News"!
It's all a hoax!!
Or,
maybe it's just a chromatic aberration because the "lens"
used (the Earth's atmosphere) is not very well ground and it
doesn't have the correct coatings. [banghead] [rolleyes2]
Of course, it is the largest lens we have within
several hundred thousand miles...
Title: My attempt
Post by: dfw_pilot on November 20, 2016, 03:08:15 PM
I think the flash happens all the time, we just don't always see it. I've seen it when on a cruise as the flat horizon of the sea helps. Ken Rockwell describes it here (http://www.kenrockwell.com/2005maui/maui-photo-tips.htm). Below is my feeble attempt at the flash:
Title: Thanks! (Re: Anybody ever seen the Green Flash?)
Post by: elagache on November 20, 2016, 11:32:03 PM
Dear Irving, dfw, and WeatherCat shutterbugs,

Thanks Irving for posting the video link.  I finally was able to enjoy it last night - a very interesting video indeed!

Thanks dfw for the link to the explanation and for your contribution.  Clearly it is a hard effect to capture!


Cheers, Edouard
Title: Re: Anybody ever seen the Green Flash?
Post by: vetenskapsman on November 21, 2016, 04:53:38 PM
What a delightful, beautiful video on the green flash.  It captures well the nervous anticipation of the event and his restrained glee at having seen it.  What a perfect place to attempt it, Paranal, one of my bucket list destinations.

I'm sure you weather enthusiasts all know this but the green flash isn't the only refractive event at sunset - the entire sunset is!  By the time the bottom limb of the sun hits the horizon the entire disk is (line of sight) already below the horizon.  Many people I've shared sunsets with find that difficult to believe  :-X  I just tell them it adds to the ephemeral, illusory nature of sunsets.  [rolleyes2]

When we all have logged our sunset green flashes we can move on to the moon, venus, and even jupiter green flashes! 

-carl