Sunday, March 15, 2015

From the Air

Another in the series ... this time on our way to Yellowstone on Christmas eve.

The Pointy-Shadow effect, where the shadow of the clouds seems to converge on a point in the distance, even though the cloud is not pointy. Look for this effect the next time you are on a mountain peak at sunrise or sunset.

Common birds are known among birders as "trash birds". Glories like the one above are becoming "trash atmospherics" for me. Not! I still think it very cool each time I see one.

This however is something I've rarely seen, a cloud bow.  I've seen hints of them before but never one so well defined.

The basic physics of cloud bows (aka "fog bows") is the same as with rainbows, light passing through water droplets. But the cloud droplets are much smaller than raindrops. And thus diffraction effects take over. The physics of glories on the other hand is not entirely worked out.

Here is the glory with the shadow of the plane's contrail looking like an arrow that hit the bullseye of a target. As the glory is centered on the the plane's shadow, the contrail shadow can't help but hit the target.

Put them all together and you have the contrail shadow "arrow" going from the bow to the glory "target". I wonder how many of my fellow passengers noticed even one of these phenomena?

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