Morning Lights

[farrari]

Can any one confirm that around dawn you can see for a few seconds what looks like flashes in the sky. I saw this in Sydney, Australia 19th september looking SE. Is this normal, who else has seen it, if so what causes it and does it have a name.

[ACARS]

Was it raining? Could you hear thunder?

[This message has been edited by ACARS (edited 20 September 2000).]

[farrari]

No, it was a clear sky, no noise at all.

[Self Loading Freight]

Sounds like it might be the Green Flash to me. That's an effect where the atmosphere acts as a prism, and bends part of the sun's light enough to be seen when the body of the sun's just beneath the horizon. Like a prism, the amount of bend depends on the frequency of the light, so the flash is typically green or blue/green as these are the components that are bent the most.

I've only heard of this happening at sunset, but can't see any reason why it wouldn't happen at dawn. If you're at altitude, then you'll have a better chance of seeing it than if you're on the ground.

A good discussion of the effect is at
http://www.mtwilson.edu/Tour/Lot/Green_Flash/

Does that sound like it matches your observations?

R

[farrari]

SLF, thanks for your reply, although i found the Green flash article interesting, my observation was to the SE or more so SSE and not over the sun itself, with out colour , just whitesh light, therefore i do not think it was this.{ timing does fit} Thanks again.May be i had to many VB's!

[This message has been edited by farrari (edited 21 September 2000).]

[Goldie]

Could it have been a flash of brilliance being sent to transport bofins for the games