March 8, 2012

The green non-flash

A MESSAGE from "Crystal," in the Sea of Cortez says:

"Before we left San Diego we head lots of stories from fellow cruisers about how easy it is to see the fabled green flash at sunset.  We've been in the Sea of Cortez for more than a month now, and we haven't seen any sign of a green flash.  What are we doing wrong?"

Well, Crystal, first of all, you need a sea horizon to the west of you at sunset. If you're in the Gulf of California you have land to the west of you all the way from Cabo San Lucas north almost to the U. S. border.  That means you won't see the sun set  over the sea unless you are a good distance offshore, and I imagine that you're pretty close to the shore when you anchor most nights.

Secondly, the green flash is an elusive phenomenon. You can watch until you're blue in the face and never see one.  But on rare occasions, when atmospheric conditions are right, you might see a green flash in the very last rays of the setting sun as it sinks into the sea.

It has been mentioned by several well-known ocean voyagers, and I've seen it myself in the middle of the South Atlantic on a calm evening in the southeast trades. It usually lasts only a fraction of a second but you can prolong it slightly by standing up immediately you see it. If you're really lucky, your boat might be lifted on a swell at that moment, which will save you the trouble of standing up, but don't count on it.

There are a lot of pictures of green flashes on the Internet to whet your appetite, Crystal. Mr. Google is just dying to show them to you. And there's a good backgrounder on green flashes by Andrew T. Young [1].  Meanwhile, however, you should steel yourself to the fact that you're not likely to see a green flash until you sail out of the Sea of Cortez. I'm afraid you're in green-flash-proof territory down there.  I'm sure there is a lot to compensate for this small loss, however.

PS:  I'm told the green flash sometimes occurs at dawn, too, when the bleary sun is just struggling over the horizon. If you're desperate enough, you might watch out for it.

Today's Thought
Nature is a rag-merchant, who works up every shred and ort and end into new creations; like a good chemist whom I found, the other day, in his laboratory, converting his old shirts into pure white sugar.
— Emerson, Conduct of Life: Considerations by the Way

"What's Paddy doing with the big roll of barbed wire?"
"He's practicing for the Irish fencing team."

(Drop by every Monday, Wednesday, Friday for a new Mainly about Boats column.)


ridgewalker said...

I saw it once while up on top of Mount Haleakala on Maui and it was indeed a sunrise. Just a fraction of a second, so if you blink you missed it. I was looking for it; but most of the other several hundred people up there did not notice it at all. Only a few of us did.

Kevin H said...

I've never seen the green flash, but I've seen the red flash a lot. Oh' just a minute, I have red/green blindness, makes those green sunsets of Brazil a real spectacle.!