People that live on Bonaire for years, made us crazy about the Green Flash, we should look at it, and ever since that time we are sitting here nearly every evening at sunset, and staring at the sun when coming down. The only green flash we have seen up to now, is a boat with that name.
Five months now, and we have never seen any green at the horizont, when the sun is setting for the night. We know allready that the sky needs to be clear, no clouds at the horizont, but we really start to think that the effect does not exist. Does someone know what to do exactly, where we have to look, is the sight in the see, or in the air, how far / near to the sun, just before, or just after sunset?
Does someone have pictures of the effect?
And last but not least, does someone know a good technical explanation of what happenes, as far as I know it is just a "tromp d'euil"; the eye gets false information, which also means that there will not exist pictures.

I'm wondering,

Harrie

Here you are Harrie

Green Flash Information Page
What Is The Green Flash?


by Peter Michaud
Gemini Observatory Information Manager


Lots of people talk about it, but how many have actually seen the much coveted green flash? If you haven't seen or heard of the green flash, it's simply a fleeting spot of intense green light on the horizon an instant after sunset or immediately before sunrise. Since Hawai'i is one of the best places to see this phenomena, let's explore why the green flash happens and how to improve your chances of glimpsing it safely.

First of all, when trying to spot the Green Flash don't be fooled by what I call, "The Fool's Flash". This is simply the greenish after-image burned into your retina by looking directly at the setting sun. (If you're lucky, this condition will only be temporary.) Remember, even when it's rising or setting it's still dangerous to look directly at the sun's disk. While awaiting the green flash at sunset, look away until only the very top of the sun's disk is about to disappear below the horizon - it's only during this last instant that the green flash will be visible anyway.

Secondly, the green flash is best seen when the sun sets or rises over the ocean and only when it is absolutely clear all the way to the horizon. While this might seem common in Hawai'i, distant clouds often linger on the horizon, making the green flash much less frequent than one might imagine.

In order to understand what to expect from the green flash, it helps to know how our atmosphere effects sunlight. Coincidentally, the phenomenon responsible for the green flash is also the one that paints rainbows across Hawaii's sky.

A rainbow is created when rays of sunlight enter a raindrop, bounce around inside, and exit. Light from the sun consists of a potpourri of colors that are each bent by a different amount inside a raindrop. This unequal bending of sunlight, called dispersion, ultimately sends fourth a rainbow of colors from each raindrop. It's simply a variation on this theme that makes the green flash possible.

Each day at sunrise and sunset, sunlight passes through the thickest possible layer of our atmosphere and this bends the light slightly. As the sun's rays are bent by our atmosphere, they are also dispersed or broken up into different colors, just like a rainbow. However, this atmospheric dispersion doesn't result in a rainbow. Rather, this bending of sunlight results in colored arcs of light above and below the bright orange disk of the sun.

Imagine getting a close-up look at the sun just before it sets. Studying the bottom edge of the sun's disk you'd notice a thin rim of pure red light. Above the mixed colors of the sun's blinding disk would be the light that was bent the most - a crest of vivid green light that's often thinly frosted by blue. Just after sunset (or before sunrise) this bright emerald green light at the edge of the sun glimmers over the horizon for about as long as the blink of an eye. So look carefully and don't blink!

It has been calculated that the green flash itself is far too small to be resolved by the unaided human eye. This really isn't so odd when you consider that all of the stars in the nighttime sky also appear too small to be resolved by the naked eye! Like the brightest stars and planets, the intensity of the green flash compensates for its size, producing a brilliant beacon in the twilight sky.

Over the years, some observers have reported seeing slightly different manifestations of the green flash than the one I described above. Under certain circumstances the green flash might actually appear larger, but no satisfactory theory exists to explain why. One of the most common reports describes a green ray of light projecting up from the horizon, but until I see, or better yet, photograph this phenomenon, I'll remain skeptical.

I've also been told that polarizing sunglasses can help enhance one's view of the green flash, but again I've never seen a good theory to explain why. I personally believe that almost any type of filter, polarizing or otherwise will reduce glare and improve your chance of seeing the green flash while reducing your chance of seeing the "Fool's Flash"!

Another way to improve your chances of spotting the green flash is to observe from a location that provides a clear view of the sunrise or sunset. I recommend looking for the green flash at sunset since it is easier to look in the right place at the right time. Here on Oahu, an unobstructed view of the sunset can be had from Magic Island from the second half of September until early March. During the rest of the year I like to watch sunsets from Electric Beach at Kahe Point Park in Ewa.

For green flash watchers on the neighbor islands, simply look for a west facing shore that is not obstructed by any land mass. During some times of the year, our friendly neighbor islands can also interfere. For example from May-July here on Oahu, clouds over Kauai prevent any observations of the green flash. Without going into details, it looks like most of the neighbor islands except Kauai and the southern part of the Big Island suffer from this problem to varying degrees, especially from April-August.

Harrie I can't explain it but here is a picture of it!!

try again, darn firewall

thanks Seb we may have both taken care of Harrie's question

Happy New Year Freddie. Have ya seen the flash? It's a grand thing!

No I haven't someone posted that picture a few months ago and I knew it would come in handy!!! Happy New year to you too..

Seb & Freddie,
thanks for the nice pics, and the good explanations.
Still it is strange that we didn't see it in 5 months, but we will be looking the next time of our lives, perhaps there are even more pictures coming, it looks as something really special.
If we don't succeed in seeing it here on Bonaire, we will have to go for hollidays to Hawaii? Not too bad idea?

Are there any webcam-pictures covering the green flash?

thanks,

Harrie

Harrie, although I've not seen the Green flash, I look forward to the day when I will next get to sit at the Coconut Crash and toast the beautiful Bonaire sunset whether or not I actually see anything green . Forget all that science and enjoy the romance of it! margarite

we saw a great one from Belnem last August

We've seen them in Aruba, but not yet during our trips to Bonaire...perhaps the "Green Flash" gods are still upset with us for frequenting Aruba for years.....at least until we discovered Bonaire in 1999! It does exist and one must have lots of patience...not a bad "job", tho...sitting on the beach awaiting and anticipating the Green Flash at sunset. Carole

Hi Seb. Happy New Year to you and Mary. I just got a great photo back from August of the two of you. I'll have to scan it in and send it to you.

When you spotted the green flash in August, were you wearing your polarized sunglasses? If so, do you think this enhanced your ability to view it as stated in the article? Tom

For all non-believers (like those who think that the green flash is caused only by looking through the bottom of the Heineken bottle you just finished emptying), there is a very useful website with explanations, computer models of how it happens, and photos, at http://mintaka.sdsu.edu/GF/

Yeesh! 'That last is almost more information than I wanted!!!' Good site.

I wonder: Curacao is just at/below the horizon just south of BOPEC. I wonder if it affects the formation of a green flash mirage as seen in it's direction from Bonaire?

It's amazing what one can learn by being a BT'r. I never realized that there was that much information about the green flash out there. I would be frustrated just sitting there trying see it though. This type of sighting - if you have to see it- should be done with equipment, you know?
Smile
Michelle

Harrie,

It's more of a green "blip" than a flash. Freddie's photo is an excellent representation.

Jake

Yeah, "flash" is a major-league exaggeration. We've seen it once or twice, and it's just this instantaneous thing right as the sun is disappearing at the horizon where the little smidge of sun showing above the horizon is green instead of yellow/white. It's nothing like a flash bulb going off, or anything like that...

Faith

Hi folks!

24 hours after my question, it really is incredible, so many good answers, pictures, scientifically answers on one simple question, what a very strong medium this is, easy to handle, for all levels, all kinds of interest. I'm just doing a chatbox since some days, but i'm really impressed! Reading all the stuff was fun, but understanding everything for a dutchman a little bit difficult, but we try......
Tonight around 6:30 pm we were looking again, no green flash, spot ore whatelse, even no full or empty beer-bottle.

Harrie

We have seen a good flash more than once on Bonaire. My particular theory is to be close to the water height, the first one we saw was from the dock at Capt. Don's.
And while we're at it, how about those spectacular early morning shooting stars?

My wife and I have seen it a half dozen times in Bonaire..

You really need to be "unobstructed" from Klein Bonaire.. last week we caught it 2 nights in a row from Karel's Dock!

We have pix too but I am not sure how to paste them here!

PS> I have looked for the Flash for MANY years and never saw it until i was on Bonaire... it was MUCH smaller and MUCH more fleeting than I imagined.. not sure why I would have thought it would not be small and fleeting!

Yeah, but if we called it the "Green Dot", who would watch! Would you sit there with a bunch of friends and some drinks waiting for the green dot? No way...uncool!
By the way, the pool deck at Divi provides great viewing in January for the green flash, as does the Flamingo Nest Bar area there also. Not so in August, due to the change in the setting sun and consequent obstruction by Klein Bonaire.

I still don't believe it! I spent 11 days on Bon in July, and just came back from 3 wks there and never once saw the Green Flash! Seems on the nights I didn't get to see the sunset, there were green flashes....sounds like some kind of conspiracy to me!

seen them a couple times in canada over lake huron. good excuse to watch sunsets whereever you are

In talking about the green flash with a friend who has spent a lot of time sailing, he says he has seen it at sunrise in the Carib.

Has anyone else had this experience, anywhere?

We've been lucky enough to have seen a sunset green flash from the Tipsy Seagull two nights in a row in January, 2002.

Charles Poteet
Dallas

Sunrise? Wow...have not seen too many of those over the waters even in NJ! LOL. Must be nice, tho. Will have to make an effort to get over the the "other side" of the island at sunrise to check it out. Carole

Carole,

One of the info links at the top of this thread talks about morning green flashes. One consideration is that because the flash is so short, you must know quite where the sun is going to rise along the horizon because the flash precedes the sun.

Total reversal, eh? We have seen the sunset Green Flash and now have to gauge the sunrise event...something to look forward to and another challenge...the "fun" kind of challenge! Thanks. Carole

YES, YES, we've seen it!

As starter of this thread i must tell you, we have seen the green flash, tonight, we were just having our desert, and it was there. the green flash, allthough i would say, it wasn't much more than a green spot, and quite disappointing, but Jake said that it was a quite longlasting one. We will absolutely look more often in the future, and it is absolutely sure, the sky needs to be as free as possible from clouds, because otherwise you won't see it.
Thanks everyone for the reactions, and I am glad to join the party of the Green-Flash-viewers.

harrie

It's Green Flash-time

The third green flash in 3 days, I really think it is depending on the wether, (cloudless), and that we know now what we are looking for.

harrie

I too have seen the flash from the raft that was in front of the Flamingo Beach Club in '69 actulally saw it several times the waves must be calm and reserve your looking till the very last moment

I was puttering around in my computer files tonight and came across the picture below, just in case anyone still has a doubt about the existence of a 'green flash' or how it happens. The image is from a Sand Dollar Dive & Photo brochure of a few years ago. I suspect the image was taken by Jim Brandon, then their photo pro, from his house up the hill in Santa Barbara. I know he was trying, with a 35mm camera on his astronomical telescope.

I was puttering around in my computer files tonight and came across the picture below, just in case anyone still has a doubt about the existence of a 'green flash' or how it happens. The image is from a Sand Dollar Dive & Photo brochure of a few years ago. I suspect the image was taken by Jim Brandon, then their photo pro, from his house up the hill in Santa Barbara. I know he was trying, with a 35mm camera on his astronomical telescope.